PWM Charge Controller Not Entering Float Mode

MaccaMacca Registered Users Posts: 15 ✭✭
Hi all, I'm a newbie to solar charging, so if I'm asking a stupid question, please forgive me.

I've recently just installed an 110AH LA battery in our trailer tent accompanied with a rather trick custom made output panel (lots of usb outlets, a couple of cigar sockets, an LED lighting connector and 3 Pin faceplate connected to an inverter).
It involved removing 2 full length drawers, dividing the space in two, putting the battery and panel on one side and making a new, double height drawer for the other side.

That's all just setting the scene though :).

To keep the battery topped up when we're away camping, I have a 80w suitcase solar panel with the generic blue 20a PWM controller.

I noticed last week that the controller didn't appear to enter float mode when the battery looked to be full, but being in a field in the middle of nowhere I was limited to the checks I could do.

Now I'm back home, I thought I'd have a proper look.

So, using another 110AH battery I have in the garage for convenience i did a bit of playing.

First, I charged the battery using my 10a mains charger. When full the battery was measuring 13.1v using my multimeter.

However, when connecting the battery to the controller, the controller listed 12.9v, so it appears to under read a couple of tenths (both measurements were taken using a 2 foot, 30a cable - So the readings are like for like).
I don't know if this is relevant or not.

The controller has the bulk charge voltage set to 14.4v and the battery type to LA.
The float voltage is set to 13.7v.

I connected the panel/controller up to the battery this morning and pointed it at the sun.

The panel display was showing 14.4v going into the battery (confirmed by the multimeter, well it was 14.5v but it's close enough).

What I was expecting is that after a short while, that the controller would drop to the 13.7v float mode as the battery was already full.
It didn't, it just sat pumping 14.4v into the battery for a couple of hours.

I disconnected it and checked the battery with the multimeter again and it was still sat at 13.1v.
I connected the panel up again later in the afternoon with the same result.

So, it looks like the controller doesn't want to enter float mode for some reason...
Is it just cheap/nasty and no more than an in/off switch?

Is there anything else to try, or do I just bite the bullet and get another controller (if so, any recommendations)?

I'm obviously worried about overcharging the battery when we're away camping. We might only use 10ah overnight which will easily be replaced in 3 hours the next day, but the sun might be shining for 10...

Thanks for taking the time to read this.

Macca
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Comments

  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    Welcome to the forum Maca,

    It is difficult to tell from what you have told us--To understand what is happening.

    What type of battery? Flooded cell lead acid, AGM, Li Ion of some sort or what?

    What brand/model of charge controller do you have (link to unit is fine)?

    More or less, a charge controller will:
    • First connect the battery bank, then the solar array (battery first connect, and last connect). If you connect solar first, it is possible to "confuse" the charge controller (or even damage it).
    • Next, the charge controller measures the battery voltage (9.0 to 18 volts or so==set 12 volts; higher set 24 volts).
    • When the charge controller starts charging, it will output 100% of the available current from the solar array and monitor the battery voltage (need relatively short/heavy wire from charge controller to battery bank--Maximum of 0.05 to 0.10 volts or so voltage drop from controller to battery bank).
    • The solar charge controller keeps outputting full solar panel current to the battery until the battery bus reaches around 14.4 to 14.8 volts (depending on charge controller settings). Once the battery bus reaches the charging voltage set point, the controller limits current to hold ~14.x volts for 2-6 hours or so (deeper discharge, longer "absorb" cycle typically). After holding absorb charge for X hours, then it will drop back to ~13.6 volts or so for float (and hold that as you put loads on the battery bank).
    • Once the sun sets, the battery charger will sleep until the next morning. If the battery is below ~12.7 volts (this is highly variable between brands/models), the controller will start charging again up to 14.x volts, hold for X hours, then go to float again.
    And there is the question about how much power (amp*hours) you are using... And if you are using the AC inverter, how much AC power, and how much current the AC inverter takes just being "turned on" and no loads (usually something like 0.5 to 1 Amps for smaller inverters).

    Your 80 Amp panel, in/around Sheffield UK, facing south:
    http://www.solarelectricityhandbook.com/solar-irradiance.html

    Sheffield
    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 37° angle from vertical:
    (For best year-round performance)

    JanFebMarAprMayJun
    1.14
     
    2.02
     
    2.65
     
    3.46
     
    4.02
     
    3.89
     
    JulAugSepOctNovDec
    3.96
     
    3.75
     
    3.02
     
    2.24
     
    1.37
     
    0.98
     
    So, for today, assuming:
    • 80 Watts / ~17.5 volts Vmp = 4.57 Amps Imp (voltage maximum power, current maximum power)
    • 4.57 amps * 3.02 hours average sun (September) = 13.8 AH per day (September average for Sheffield UK)
    If your battery was a 1/2 charge (50% state of charge), it would take around:
    • 110 AH * 0.50 state of charge = 55 Amp*Hours "used"
    • 55 Amp*hours / 13.8 AH per average Sept day = ~4 days of "full September sun" to recharge from 50% state of charge
    If you have a flooded cell battery, you can use a hydrometer to check each cell's specific gravity and get a more accurate state of charge:

    https://www.solar-electric.com/search/?q=hydrometer

    Anyway, lots of information and guesses... Your thoughts/questions?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 5,576 ✭✭✭✭✭
    Solar battery chargers go through a 3 stages of charging, once they reach the 'bulk/absorb setting, the battery slowly reduces the amount of current it takes in... Reaching absorb voltage where the charge controller stops the voltage from increasing only means that the battery has reached about 80-85% full. At this point the charge controller doesn't let the voltage run any higher, and it waits for the current to be reduced or stops after a timed period and drops into float.

    Stages of Charging;

    During charging, there are basically 3 stages of charging, Bulk, Absorb, and Float.

    BULK;
    First thing when charging starts you will be in bulk, the voltage rises from what ever the system voltage was to a set point, around 14.5 volts. At that point the Charge controller stops the voltage from rising. Higher voltage can damage sealed batteries.

    ABSORB;
    Once the battery hits the preset point the charge controller keeps it at that point. Your batteries are roughly 80% full. Flooded batteries will start accepting less current at 80-85% full AGM/Sealed may go a little longer before accepting less current.

    On many controllers you can set this point, Some will have different presets for Flooded, and sealed batteries, or flooded, AGM, and sealed batteries. 

    The charge controller has a couple ways to know when to switch to float, Most inexpensive Charge controller are just timed for 1.5-2 hours. Some will also see less current flowing through the charge controller and shut it down when minimal current is flowing through the controller. On more expensive charge controller. You can set battery capacity to give the Controller a better idea of when to stop. you can also set a longer Absorb time. Or set 'end amps' a amount of amps flowing through the charge controller to stop Absorb and switch to the final stage.

    FLOAT;
    Once the Controller has determined the battery is fully charged it reduces the voltage to a point where very little current is flowing to the battery. This will prevent the battery from over charging and heating up.

    While in 'Float' the charge controller watch for voltage drop, which would indicate a load. If the voltage begins to drop the charge controller will allow as much current to flow from the panels/array to compensate and maintain the voltage. If the voltage can be maintained, the load will in essence be running directly off the array/solar. If the voltage drops below the preset float voltage, the controller may start a whole new cycle if it stays there for a period of time.

    The system voltage drop you see at night when the sun goes down is the charge controller moving into a resting mode with no energy to contribute to the system.

    The morning voltage may reflect a load present that is effecting the voltage level. With sealed batteries, you would want to disconnect the battery from the system and allow it to 'rest' for a while to get an accurate idea of it's SOC (State Of Charge) from the voltage. 

    Looking at the battery voltage as soon as the battery is disconnected is still not a good idea of the State Of Charge (SOC) you would have to let the battery 'rest' for a while before getting any idea...
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited September 2020 #4
    Your withdrawals are likely greater than the income which means you're running a deficit, my guess is everything seemed to work fine when the battery was new but has begun to show the symptoms as of late. The 80W is insufficient perhaps 200-300 watts would be close to what's needed, this depends on geographic location as well as local weather trends. 

    Don't worry so much about overcharging, but rather undercharging, the controller will/should regulate itself once satisfied in the absorption stage, or may never transition to float if the battery is damaged due to sulfation. This is speculative as details of the equipment are unclear,
    but rather based on typical overestimating the systems  capabilities, which common for beginners.    
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • MaccaMacca Registered Users Posts: 15 ✭✭
    edited September 2020 #5
    Hi all,

    Thanks for the replies, hopefully I can answer some of the questions below:

    Here is the type of controller I'm using.
    https://www.amazon.co.uk/Controller-Intelligent-Regulator-Control-Display/dp/B07Y4Q7V3D/ref=mp_s_a_1_1_sspa?dchild=1&keywords=solar+charge+controller&qid=1599644057&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExNzVXUFJLOUYwRllNJmVuY3J5cHRlZElkPUEwMjcxMDUzM1FOQjVKTzFINkYwNyZlbmNyeXB0ZWRBZElkPUEwMTA2Njg2M0JSTU5NTUk2R1I1VSZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

    The battery is a flooded cell lead acid (sealed).

    At the moment, the solar panel is not connected to the trailer tent - I'm testing against another battery I have spare in the garage.

    So, I charged the battery overnight using my mains 10a charger.
    Voltage was at 13.1 as measured by the multimeter via the same cable used to connect to the charge controller (I know that this is just surface charge)

    The battery was then connected up to the solar panel with the PV input switched off.
    The charge controller only reads 12.9v (this 0.2v under read on the charge controller is consistent across the voltage range).

    The PV input was then turned on and the charge controller pumped out the specified 14.4v for the next three hours until I turned the PV input of again.

    Surely, as the battery was already 100% charged before beginning connected to the charge controller it should have gone into the float stage in that time?

    I then repeated this test an hour later with the same results. So, pretty much 6 hours in full sunlight (controller pushing out 14.4v for 90% of that time) on an already full battery and the controller never dropped into the float stage..?

    I understand the different charging stages (or I thought I did), the comments above helped solidify that knowledge.

    When we are out and about, I know how much power has been used as there is a voltmeter built into the panel.

    All inputs go via a fuse bank, which is connected to an isolater switch so there is no idle drain when not in use.
    The inverter is connected separately, but also via a separate isolater switch, and it's disconnected when not in use.

    Under changing is not a concern, as if the battery ever drops to 12.0v then the input panel gets disconnected via the isolater switches.

    The lowest we hit whilst away was 12.3v

    The battery in the trailer tent is new (6 months old but only a couple of discharge cycles), before fitting it I did check it's capacity by hooking up a 50w car bulb to it (4ah load) for 12 hours and we were still showing 12.1v, so unless there is a better way to check in as sure as I can be that the battery is good.

    The battery I'm testing with is around a year old, but has only had around 20 discharge cycles.
    I haven't done a capacity check on this one however...

    Thanks

    Macca
  • MaccaMacca Registered Users Posts: 15 ✭✭
    edited September 2020 #6

    Hi all,

    Thanks for the replies, I'll try and address all of the questions below.

    The battery is a Flooded Cell Lead Acid battery (sealed)

    The charge controller is the same as one of these:

    https://www.amazon.co.uk/Controller-Intelligent-Regulator-Control-Display/dp/B07Y4Q7V3D

    Regarding charging stages/cycles, I had a pretty solid understanding but the provided information helped solidify it.

    Just to answer questions about usage in the trailer tent.
    The panel has a voltmeter on it, so I can keep tabs on the usage/state of charge from there.

    All of the inputs run via a fuse box, which is runs via an isolator switch so there is no idle drain when not in use (all of the inputs are separately switched as well but we just flick the isolator when nothing is in use)

    The inverter is also connected separately, but via a separate isolator switch and is disconnected when not in use.

    Undercharging isn't really a concern as is the battery ever drops to 12v, I'll just disconnect the panel so no much power can be drained.
    The lowest we hit when away recently was 12.3v and we were always back to 12.6/7v by the end of the day.

    Before fitting the battery to the trailer tent, I did check it's capacity by running a 50w bulb from it (4ah load) for 12 hours and we were still showing 12.1v, so I'm as sure as I can be that it's ok (it's only 6 months old with under 10 cycles on it)

    Just to clarify, the recent testing I'm doing is against a completely separate 110ah Flooded Cell Lead Acid battery I have spare in the garage.
    This one is a year old with around 20 cycles on it (i've not tested the capacity on it like the other battery)

    Both batteries charge fine on the mains 10a charger and correctly go through the Bulk and Absorption stages before going into float mode

    So, my recent testing was as follows:

    • Spare battery charged overnight on the mains 10a charger
    • Voltage measured in the morning with the multimeter at 13.1 volts (I know that this is just surface charge) - The measurement was taken via the same 30a cable used to connect up the charge controller
    • Battery was connected to the charge controller with the PV input switched off
    • Charge controller reads 12.9v (this 0.2v under read is consistent across the voltage range)
    • Panel is faced into the sun and PV input is switched on
    • Panel reports 14,4v being fed to the battery (Multimeter reads 14.5v but it's close enough) - 14.4v is the limit set in the controller
    • We wait for 3 hours, pretty much direct sunshine for that time period
    • Panel is still feeding 14,.4v into the battery - By this point i would have expected it to have dropped to the float voltage of 13.7v given that the battery was already fully charged when connected.
    • I disconnected the panel for 1 hour
    • I reconnected the charge controller and switched the PV input back on for another 3 hours (battery was reading 13.1v on the multimeter before connecting back up
    • 3 hours later the charge controller is still feeding 14.4v into the panel
    So we had a full battery connected up the solar panel/charge controller for 6 hours (85-90% direct sunlight during that time) and the controller never switched into float mode.

    So my concern is that I will be cooking the battery in these conditions..?

    Thanks
  • mike95490mike95490 Solar Expert Posts: 9,274 ✭✭✭✭✭
    >  The battery is a Flooded Cell Lead Acid battery (sealed)

    uh, no.   There is
    Flooded, with caps that you must add distilled water to monthly
    and Sealed, which come in 2 types
    AGM (better for solar as it can be charged faster, has Absorbent Glass Matting wedged between the plates)
    Gel ( not good for solar as the electrolyte is gelatin like and can develop permanent gas voids/bubbles if charged fast)

    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    Generally, it is best to leave the charge controller (and solar panels) connected to the battery bank and let them do their job when stored.

    The controller says it has a 13.5 volt float mode... Perhaps you need time (and a full battery) for it to get there.

    Solar charge controllers can draw a bit of energy when "dark". If you leave the controller connected without a solar panel, the controller can slowly discharge the battery over a few months (did not see the "tare" loss listed--So don't know "how fast", but controllers like this usually do not consume much power at night/no panel connected).

    I would suggest not disconnecting the solar panels and controller during storage--Unless it is under shade (like a car port/heavy trees). If you do, make sure to reconnect in the correct order (battery first, then solar panels):
    Solar Controller System Connection:
    1.Connect the battery to the charge regulator - plus and minus.
    2.Connect the photovoltaic module to the regulator - plus and minus.
    3. Connect the consumer to the charge regulator - plus and minus.
    NOTE: The reverse order applies when deinstalling! An improper sequence order can damage the controller!
    Otherwise, it does not sound like you are doing anything wrong, and the battery is still good.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    Don't assume the charging is completed based on voltage, that alone is a poor method of of determination, flooded lead acid batteries are extremely resilient to overcharging but very fragile to undercharging, the specific gravity, or SG, should be used to determine the state of charge of individual cells as apposed to voltage of the battery as a whole, a hydrometer will provide more accurate results.

    Sadly based on the information provided you are on a path of self destruction, more concerned with self presivation whilst  ignoring the actual requirements of the battery itself.Your environmental conditions are not ideal, but with practical  compensation anything is possible.

    Please don't misconstrue this as a negative comment, it is in fact constructive criticism, far too many fall into the trap of  overestimating the potential whilst ignoring the demands.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • MaccaMacca Registered Users Posts: 15 ✭✭
    edited September 2020 #10
    mike95490 said:
    >  The battery is a Flooded Cell Lead Acid battery (sealed)

    uh, no.   There is
    Flooded, with caps that you must add distilled water to monthly
    and Sealed, which come in 2 types
    AGM (better for solar as it can be charged faster, has Absorbent Glass Matting wedged between the plates)
    Gel ( not good for solar as the electrolyte is gelatin like and can develop permanent gas voids/bubbles if charged fast)

    It's a sealed 'wet' lead acid battery, but it's not Gel or AGM
    Here's a link to it
    https://www.tayna.co.uk/leisure-batteries/platinum/lb6110l/

  • MaccaMacca Registered Users Posts: 15 ✭✭
    BB. said:
    Generally, it is best to leave the charge controller (and solar panels) connected to the battery bank and let them do their job when stored.

    The controller says it has a 13.5 volt float mode... Perhaps you need time (and a full battery) for it to get there.

    Solar charge controllers can draw a bit of energy when "dark". If you leave the controller connected without a solar panel, the controller can slowly discharge the battery over a few months (did not see the "tare" loss listed--So don't know "how fast", but controllers like this usually do not consume much power at night/no panel connected).

    I would suggest not disconnecting the solar panels and controller during storage--Unless it is under shade (like a car port/heavy trees). If you do, make sure to reconnect in the correct order (battery first, then solar panels):
    Solar Controller System Connection:
    1.Connect the battery to the charge regulator - plus and minus.
    2.Connect the photovoltaic module to the regulator - plus and minus.
    3. Connect the consumer to the charge regulator - plus and minus.
    NOTE: The reverse order applies when deinstalling! An improper sequence order can damage the controller!
    Otherwise, it does not sound like you are doing anything wrong, and the battery is still good.

    -Bill
    Hi Bill,

    Leaving the panel hooked up whilst in storage is not an option (the trailer is stored in a custom-built shed).
    I'm not sure it's necessary for me in any case?
    I do have an external charging point on the trailer and when it's packed away nothing is actually connected up to the battery other than the charging socket ( everything runs via isolator switches), so it's just keeping on top of the self-discharge as far as I'm aware?

    Regarding the float mode, that's the real question - The battery is full from a mains 3-stage charger and then connected to a solar panel.
    Even after 6 hours of daylight, the controller still outputs 14.4v and doesn't drop in to float mode...

    Thanks

    Macca
  • PhotowhitPhotowhit Solar Expert Posts: 5,576 ✭✭✭✭✭
    edited September 2020 #12
    Sorry, It appeared you came here for information and knowledge. Wish we could have given you the answer you wanted.
    So I prepared a few more answers.

    Charge controller is clearly toast, better toss it and get a new one.

    Solar just won't work for you, just charge a battery at home and use it when you need to.

    I've not got a clue, perhaps you should speak with your local solar professional.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • MaccaMacca Registered Users Posts: 15 ✭✭
    mcgivor said:
    Don't assume the charging is completed based on voltage, that alone is a poor method of of determination, flooded lead acid batteries are extremely resilient to overcharging but very fragile to undercharging, the specific gravity, or SG, should be used to determine the state of charge of individual cells as apposed to voltage of the battery as a whole, a hydrometer will provide more accurate results.

    Hi there,

    Given that it's a fully sealed battery, I'm not sure I have any other option than relying on voltage readings to measure charge level do I?
    Other than conducting a load test as I did before installing the battery in the first place..?
    mcgivor said:
    Don't assume the charging is completed based on voltage, that alone is a poor method of of determination, flooded lead acid batteries are extremely resilient to overcharging but very fragile to undercharging, the specific gravity, or SG, should be used to determine the state of charge of individual cells as apposed to voltage of the battery as a whole, a hydrometer will provide more accurate results.

    Sadly based on the information provided you are on a path of self destruction, more concerned with self presivation whilst  ignoring the actual requirements of the battery itself.Your environmental conditions are not ideal, but with practical  compensation anything is possible.

    Please don't misconstrue this as a negative comment, it is in fact constructive criticism, far too many fall into the trap of  overestimating the potential whilst ignoring the demands.

    mcgivor said:
    Don't assume the charging is completed based on voltage, that alone is a poor method of of determination, flooded lead acid batteries are extremely resilient to overcharging but very fragile to undercharging, the specific gravity, or SG, should be used to determine the state of charge of individual cells as apposed to voltage of the battery as a whole, a hydrometer will provide more accurate results.

    Sadly based on the information provided you are on a path of self destruction, more concerned with self presivation whilst  ignoring the actual requirements of the battery itself.Your environmental conditions are not ideal, but with practical  compensation anything is possible.

    Please don't misconstrue this as a negative comment, it is in fact constructive criticism, far too many fall into the trap of  overestimating the potential whilst ignoring the demands.

    Without meaning to sound defensive, I genuinely don't understand this comment.

    What path of self-destruction am I on and what requirements of the battery am I ignoring?

    As far as I'm aware, I'm just trying to ensure that the battery doesn't get overcharged when we have gone out for the day, there are 10 hours of sunlight and there has only been a couple of amps of charge used up the previous evening (which happens often as we typically only run a couple of strips of LED lighting in the evening).

    If you could enlighten me, I'd be most grateful

    Thanks

    Macca
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    For the most part, Lead Acid batteries are "killed" by under charging/over discharging. Rarely damaged by over charging.

    Sealed Lead Acid batteries are sensitive to over charging. They recombine the Hydrogen and Oxygen generated during the last stages of charging (as you get to 14.4 volt). Some use a catalyst (platinium, palladium, similar) which does wear out over time... And the longer/higher charging voltages, the more gasses generated, the faster the catalysts wear out.

    And once a sealed battery generates more gasses than can be recombined (high charging voltages, failed catalysts), the batteries will vent the gasses (and mist), and the batteries lose water, and eventually die.

    If you are using the solar panels during outings, then this controller appears to be mostly working. Just use a float charger (good quality) to keep the battery happy in storage.

    However, if there is a problem with the solar charge controller--There is always the chance that further problems will develop when you are on a trip (stop charging, other issues).

    Most charge controllers are not repairable--So you are generally left with warranty support or just buiting the bullet and getting a new one that hopefully will work better.

    And a controller that costs £10.59.

    There just is not a lot of money there vs the 100 Pounds or more you probably spent for the battery itself.

    It is difficult to debug/diagnose solar charge controllers because there are the variables of solar, battery, time on charge, charging current, etc... So getting an actual good/bad determination in that environment is difficult.

    But tat this time, yes, it sounds like your controller is not working correctly. Have you gone through the setup menu? Sometimes, "resetting" to factory defaults (or changing a setting, save, then change it back) is needed to fix a "corrupted" settings memory. I would try that first.

    And there is at least one complaint about not entering float:

    Answer:
    Do not need adjust the setting because the microprocessor does it for you, it will know the battery you have connect to.
    You only need adjust the setting if you are electronic engineer.
    Mr wizard. see less
    By Mr. Wizard. on 01 July 2020

    We have seen lots of people "kill" their battery banks from under charging/over discharging (weak solar arrays and charge controllers, large loads, not much sun, failed hardware). Just don't want to see it happen to you too.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MaccaMacca Registered Users Posts: 15 ✭✭
    BB. said:
    For the most part, Lead Acid batteries are "killed" by under charging/over discharging. Rarely damaged by over charging.

    Sealed Lead Acid batteries are sensitive to over charging. They recombine the Hydrogen and Oxygen generated during the last stages of charging (as you get to 14.4 volt). Some use a catalyst (platinium, palladium, similar) which does wear out over time... And the longer/higher charging voltages, the more gasses generated, the faster the catalysts wear out.

    And once a sealed battery generates more gasses than can be recombined (high charging voltages, failed catalysts), the batteries will vent the gasses (and mist), and the batteries lose water, and eventually die.

    If you are using the solar panels during outings, then this controller appears to be mostly working. Just use a float charger (good quality) to keep the battery happy in storage.

    However, if there is a problem with the solar charge controller--There is always the chance that further problems will develop when you are on a trip (stop charging, other issues).

    Most charge controllers are not repairable--So you are generally left with warranty support or just buiting the bullet and getting a new one that hopefully will work better.

    And a controller that costs £10.59.

    There just is not a lot of money there vs the 100 Pounds or more you probably spent for the battery itself.

    It is difficult to debug/diagnose solar charge controllers because there are the variables of solar, battery, time on charge, charging current, etc... So getting an actual good/bad determination in that environment is difficult.

    But tat this time, yes, it sounds like your controller is not working correctly. Have you gone through the setup menu? Sometimes, "resetting" to factory defaults (or changing a setting, save, then change it back) is needed to fix a "corrupted" settings memory. I would try that first.

    And there is at least one complaint about not entering float:

    Answer:
    Do not need adjust the setting because the microprocessor does it for you, it will know the battery you have connect to.
    You only need adjust the setting if you are electronic engineer.
    Mr wizard. see less
    By Mr. Wizard. on 01 July 2020

    We have seen lots of people "kill" their battery banks from under charging/over discharging (weak solar arrays and charge controllers, large loads, not much sun, failed hardware). Just don't want to see it happen to you too.

    -Bill
    Hi Bill,

    That's incredibly useful - I had searched for similar issues but had not thought to go through Amazon reviews.
    So it looks lie at least one other person has the same issue as me!

    I did try going through the menus yesterday and I set the float voltage to a couple of different values, but to no avail.
    I'll see if there is a factory reset, if not I still have the original instructions which I think have the default values in there.

    If that makes no difference, then I think we are looking at a new controller - Any recommendations?

    Cheers

    Macca
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    I am not in the solar business (retired systems engineer)... I will point you to our host's website (Northern Arizona Wind & Sun)--They have very good equpiment that they stand behind (and provide engineering support for). However, I would expect you to buy locally (UK).

    https://www.solar-electric.com/residential/charge-controllers.html

    But NAWS is going to cost around $50-$100+ for their controllers.

    EPEVER and a hundred different imports are out there that are less expensive (Amazon, Ebay, etc.). And there have been issues with just about every brand out there (including the $600 to $1,000 models too).

    Many of the problems are user error (miss programming, connecting battery after connecting panels, corrupted databases, etc.). But past the simple things to do (disconnect controller, let sit for 1 minute, then connect battery first; clearing database, factory reset, checking wires from controller to battery bank--Where you want around 0.05 to 0.10 volts maximum drop for 12 volt battery bank; check for loose/overheated/corroded wiring, etc.).--There is not much more you can do.

    Some others here with more experience than I can probably give you some lower cost brands/models that will work well.

    Sincerely,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mike95490mike95490 Solar Expert Posts: 9,274 ✭✭✭✭✭
    >  Labyrinth Lid

    OK, so if they sell it as a flooded with a spill proof lid, you need to be able to water it monthly.
     I am surprised it only has a 2 year warranty .
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • MaccaMacca Registered Users Posts: 15 ✭✭
    mike95490 said:
    >  Labyrinth Lid

    OK, so if they sell it as a flooded with a spill proof lid, you need to be able to water it monthly.
     I am surprised it only has a 2 year warranty .
    Yeah, there is no way you can top this one up. It's basically fully sealed with just a vent.
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    @Macca You have to understand that responders can only offer advice based on their personal knowledge and experience, the accuracy of the information  provided will be directly related to the  information you  provide.

    From an outside perspective it would appear you are under paneled which could result in battery failure, the emphasis being on the word could, without detailed information such as load current along with duration, it's impossible to know how much of the battery capacity is being used, which corresponds to what needs to be replaced.

    Let's assume the battery is fully charged, this would be represented by a standing voltage of around 12.8V, 4 hours after charging without any loads.  Apply a load of approximately 10 amps to the battery whilst measuring the voltage, the voltage will drop but should stabilize to 12.xx V, if the voltage continues to drop rapidly the capacity is low.

    Next step is to connect your 10A charger with a multimeter connected, the voltage should rise slowly, if it climbs rapidly to 14+ volts that would indicate a failed battery.

    The controller linked is known to fail in a short condition, but the result would be a voltage increasing above 14.4V, if it remains at that value you need to measure the current flow to the battery, this will establish if in fact the controller is in the absorption stage. The current should drop slowly as it approaches it's transition to float, this is assuming the battery is healthy.


    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • MaccaMacca Registered Users Posts: 15 ✭✭
    edited September 2020 #20
    mcgivor said:
    @Macca You have to understand that responders can only offer advice based on their personal knowledge and experience, the accuracy of the information  provided will be directly related to the  information you  provide.

    From an outside perspective it would appear you are under paneled which could result in battery failure, the emphasis being on the word could, without detailed information such as load current along with duration, it's impossible to know how much of the battery capacity is being used, which corresponds to what needs to be replaced.

    Hi there,

    I appreciate that people are in only trying to help, but the original question was not about my solar capacity compared to my usage (I have little to no choice about the panel size as it's about the biggest we can take away with us camping, I can maybe upgrade to 100w but that would be about it). The question was if my controller was faulty or had I been doing something wrong/misunderstanding how it should work.

    I've tried to answer any questions people had and to gently steer the discussion back on topic.

    Bill gave some great advice yesterday and even went as far as finding someone with the same issue in an Amazons question/answer section (which was greatly appreciated and going above and beyond).

    Again, I know that an 80w solar panel is not going to be able to meet the requirements any kind of even moderate power usage. Luckily, when we are off camping we are only charging phones and running LED strip lights mainly.
    The inverter is normally solely used to charge a laptop battery should I need to work whilst I'm away.

    The purpose of the setup is to get us through 7 days max of the above kind of usage, which it did last week, and in fact, when wet got home and I checked the next day, the battery was sat at 12.6v

    The only real option I would have the increase capacity would be to go for a lithium battery of a similar capacity, but they are prohibitively expensive at this point

    I still believe the main concern is boiling the battery - As it's sealed, topping it up is not something that can be done.


    mcgivor said:

    Let's assume the battery is fully charged, this would be represented by a standing voltage of around 12.8V, 4 hours after charging without any loads.  Apply a load of approximately 10 amps to the battery whilst measuring the voltage, the voltage will drop but should stabilize to 12.xx V, if the voltage continues to drop rapidly the capacity is low.
    .


    This is one thing that I have checked and the voltage stabilises at 12.xx as does not continue to drop.

    mcgivor said:

    Next step is to connect your 10A charger with a multimeter connected, the voltage should rise slowly, if it climbs rapidly to 14+ volts that would indicate a failed battery.

    The controller has a voltmeter built in and the voltage rises slowly as expected

    mcgivor said:

    The controller linked is known to fail in a short condition, but the result would be a voltage increasing above 14.4V, if it remains at that value you need to measure the current flow to the battery, this will establish if in fact the controller is in the absorption stage. The current should drop slowly as it approaches it's transition to float, this is assuming the battery is healthy.


    This is a great suggestion, I hadn't thought to check the current from the controller.
    The 80w panel should produce a max of around 4-5a correct?
    If so, what should it drop off to during the absorption stage (I've never tried to measure this before)?

    Thanks again for your help, it is greatly appreciated

    Macca
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    edited September 2020 #21
    There is an interrelationship between the battery capacity and the charge controller, if the battery has been depleted to 60% state of charge,  the charging required to bring it back to 100% would be approximately 48Ah, taking into account inefficiencies. The 80W panel will produce  around 4 amps in perfectly aligned sun, therefore it would take somewhere in the neighborhood of 12 hours, being the prime window of opportunity is restricted to 3 or so hours with less output before and after, it could take multiple days to complete the absorption.

    This is a very common for beginners who don't fully understand the nuances involved, often falling victim to cronic undercharging resulting in premature battery failure, hense the reference to other factors, battery capacity, depth of discharge etcetera, which may seem trivial and not directly focused on the perceived issue.

    Lead acid batteries have very specific needs which need to be fully understood to avoid the pitfalls, many, including myself, have learned the hard way and offer assistance to help others to not fall victim to the common misconceptions.

    Did the controller go into float when the battery was new? This is important because some low end controllers don't ever transmission to float but rather maintain a voltage of 14,4V but at extremely low current in pulses, which in itself is not harmful to the battery.

    One other thing which may or may not be relevant, the controller MUST be connected to the battery first to establish a nominal voltage of 12V, if connected to the panel first  it may establish itself as 24V nominal which will lead to problems, unlikely perhaps, but never leave stones unturned when trouble shooting.

    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • MaccaMacca Registered Users Posts: 15 ✭✭
    edited September 2020 #22
    mcgivor said:
    There is an interrelationship between the battery capacity and the charge controller, if the battery has been depleted to 60% state of charge,  the charging required to bring it back to 100% would be approximately 48Ah, taking into account inefficiencies. The 80W panel will produce  around 4 amps in perfectly aligned sun, therefore it would take somewhere in the neighborhood of 12 hours, being the prime window of opportunity is restricted to 3 or so hours with less output before and after, it could take multiple days to complete the absorption.

    This is a very common for beginners who don't fully understand the nuances involved, often falling victim to cronic undercharging resulting in premature battery failure, hense the reference to other factors, battery capacity, depth of discharge etcetera, which may seem trivial and not directly focused on the perceived issue.

    Hi there,

    This is understood and useful information, however I did try to make it clear that we were talking about the charge controller not appearing to behave when connected to a fully charged test battery, basically taking out any potential complications caused by trying to recharge 50ah of departed power with an 80w solar panel.

    When I tried to gently bring the thread babk on topic, I then received a couple of pretty passive replies that I still feel were unwarranted.

    Again, knowing that people are just trying to help I'm trying just to move on. I was thinking of abandoning this thread entirely add it appeared to be taking a wrong turn and getting upset by, or causing upset to others on an internet forum is something I have zero interest in.
    mcgivor said:


    Lead acid batteries have very specific needs which need to be fully understood to avoid the pitfalls, many, including myself, have learned the hard way and offer assistance to help others to not fall victim to the common misconceptions.

    Did the controller go into float when the battery was new? This is important because some low end controllers don't ever transmission to float but rather maintain a voltage of 14,4V but at extremely low current in pulses, which in itself is not harmful to the battery.

    Last week was the first time this controller was hooked up to the battery so the answer to that is no, it didn't.
    The specs of the controller do day that it should go into float mode at 13.7v though, however it's a cheap Chinese controller and float is actually labelled as 'bloat' in the manual do who knows...

    mcgivor said:

    One other thing which may or may not be relevant, the controller MUST be connected to the battery first to establish a nominal voltage of 12V, if connected to the panel first  it may establish itself as 24V nominal which will lead to problems, unlikely perhaps, but never leave stones unturned when trouble shooting.

    More very important and useful information.
    I'm happy to report that I always connect the battery to the charge controller before the PV input is switched on.

    Thanks again for your input.

    Macca


  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    Macca,

    The folks here care about you and your setup... Everyone is just trying their best to convey information about your system design and operation and avoid the pitfalls that almost everyone here has made at one time or another in their personal solar journeys..

    Take care,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MaccaMacca Registered Users Posts: 15 ✭✭
    Hi all,

    So the current plan is try try and measure the current from the controller to see if it's actually even entering the absorption stage. 
    I'll have to try and work out a way of connecting up the multimeter as a permanent part of the circuit as I don't have clamp leads at the moment, just probes.
    So measuring the current quickly is easy, leaving it hooked up for a period of time is going to be a bit more of a challenge.

    I've also put a call out to a friend who has a folding solar panel to see if I can borrow it on Sunday. I've got no idea what type of controller it's using, but it should give me a known working unit to compare/contrast against.

    Cheers

    Macca

  • mike95490mike95490 Solar Expert Posts: 9,274 ✭✭✭✭✭
    If you have seen the battery voltage slowly rise to 14.x volts, hold there for an hour, then, depending on the algorithm your controller uses, it should transition to float.   If the battery does not reach the required voltage, the Absorb timer will never start.
     You can use a ampmeter to see if the panel is producing enough amps to actually charge the battery, but you don't need to leave it connected all the time, the charge controller does not measure amps, it simply measures volts and starts various timers according to the voltage  (stage 2 in the graph, is Absorb)


    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • MaccaMacca Registered Users Posts: 15 ✭✭
    Quick update - I managed to get my hands on my friend's solar panel setup - It's a 120w foldable panel with a 20a PWM controller (different model to the one I have).

    His controller actually shows the current, so it's going to be useful for testing!.

    I hooked it up about an hour ago to my test battery (full, bright sunshine at the moment) and the current to the battery was 2a.
    I've just checked again now and it's down to 0.4a @ 14.4v, so I believe that means it's in the absorption stage at the moment.

    It looks like full sunshine for the rest of the afternoon, so I'll keep checking on it to see if/when it goes into the float stage.

    Cheers

    Macca
  • mcgivormcgivor Solar Expert Posts: 3,815 ✭✭✭✭✭✭
    The PWM controller may not go into float if not designed to do so,  0.4A  at 14.4V would be typical of a cheaper type controller, which would indicate a battery at near enough to fully charged.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • MaccaMacca Registered Users Posts: 15 ✭✭
    mcgivor said:
    The PWM controller may not go into float if not designed to do so,  0.4A  at 14.4V would be typical of a cheaper type controller, which would indicate a battery at near enough to fully charged.
    Hi there,

    Both my friends and my PWM controllers are designed to go into float mode (according to their specs in any case, but this is backed up by you being able to configure the float voltage in both of them).

    I've just checked the controller again and it has entered float mode - It's now passing through the configured float voltage of 13.7v (the current is 0.4a)

    So I'm happy to conclude that my cheap, Chinese PWM controller is not working as expected and will not enter float mode even when the battery is full.

    I'll look at picking up the same make/model as my friend has, at least I know it does what it says on the tin!

    Thanks

    Macca
  • MaccaMacca Registered Users Posts: 15 ✭✭
    Ok, possibly my final update.

    I want for what I thought was one of the better quality PWM controllers.

    https://www.amazon.co.uk/dp/B07CZNYPR1/?coliid=I108PV7UKMGQAD&colid=O8ICPH17GPK1&psc=1&ref_=lv_ov_lig_dp_it

    As we were going with a new controller, I decided to take the opportunity to reconfigure things a little.

    As I'm using a folding suitcase type panel, the supplied (old, not working correctly) controller is directly attached to the inside of the suitcase frame/panels.

    This makes it very neat and portable, but it means that the cable length to the battery is always going to be longer than ideal - 3 meters is typically what's required (i have 1m, 3m and 5m cables that be combined if needed).

    So I've taken the option of not having the controller attached to the suitcase so that the longer cable runs will be from the PV to the controller.

    I've also made some new battery to controller cables out of 120a wire for the entire 1.5m run to the battery (old motorbike jump/starter cables that I've repurposed).

    So, everything has been connected up the trailer tent this afternoon and appears to be working like a charm.

    The controller reads the same battery voltage as the multimeter (measured down the same battery to controller connection cable), which is a good start.

    The panel was outputting 3.8a as I connected it up to the controller and when I checked on the controller a few minutes later, it was only outputting 1a to the battery, so it would appear that it out had correctly entered the absorption stage.

    I've just checked a hour later and the controller has switched over to float mode, out putting 0.7a at the set 13.8v float voltage).

    So, I think we are there.

    I'll look at seeing if I can pickup one of the higher output folding panels that are fabric backed instead of using an aluminium frame.

    This is the type my friend has and it's pack size is considerably smaller than my suitcase type.

    You can get them in 150w/200w versions, so if I can find one at the right price point, I'll grab one (unless anyone has a good reason not to use this type of panel)?

    Cheers

    Macca
  • BB.BB. Super Moderators, Administrators Posts: 31,684 admin
    edited September 2020 #30
    Sun/UltraViolet and Heat are killers for solar panels (and anything outside made of plastic, such as wire insulation).

    Flexible/Semi-Flexible panels generally have lots of plastic (plastic top cover, etc.) to remain flexible.

    And, maybe too wide of generalization, I would not expect such panels to last more than a couple years in full sun--And sometimes just months if there is lots of flexing involved.

    On the other hand, if you are camping a few weeks a year, a "2 year" life may be 10 years of calendar life (store panels away from sun when camper is parked) and they may be the best for your needs (folding, light weight, etc.). Especially if you are not paying extra money for the folding/flex panels.

    If, the panels were going to be in the sun for 9+ months a year--Then permanently mounting standard glass+aluminium frame panels will last much longer (unless they get hit by road rocks/etc.).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MaccaMacca Registered Users Posts: 15 ✭✭
    BB. said:
    Sun/UltraViolet and Heat are killers for solar panels (and anything outside made of plastic, such as wire insulation).

    Flexible/Semi-Flexible panels generally have lots of plastic (plastic top cover, etc.) to remain flexible.

    And, to may a wide generalization, I would not expect such panels to last more than a couple years in full sun--And sometimes just months if there is lots of flexing involved.

    On the other hand, if you are camping a few weeks a year, a "2 year" life may be 10 years of calendar life (store panels away from sun when camper is parked) and they may be the best for your needs (folding, light weight, etc.). Especially if you are not paying extra money for the folding/flex panels.

    If, the panels were going to be in the sun for 9+ months a year--Then permanently mounting standard glass+aluminium frame panels will last much longer (unless they get hit by road rocks/etc.).

    -Bill
    Thanks Bill,

    Yes, in my case we are talking about 30-50 days a year max.
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