HOW TO AVOID BATTERY MISUSE (while away)?

JakachiraJakachira Solar Expert Posts: 47
I have a problem, people

I installed a solar system in my rural area. The system is used by my parents and my younger brothers. The issue is that they have been cooking all the batteries i buy so much that every time i make my way home i have to do a battery replacement.

They do not use Solar controller to charge the batteries no matter how many times i explain to them the use of it. I recently bought a third regulator (Steca PR3030 with LCD monitor) thinking maybe they might be able to see that the batteries actually charge but that didn't help either. Removing the system altogether is not an option.

I was thinking of hiding a mere solar controller beneath the mounted panels and let them to what ever they want .Is it possible to use two regulators in one system. I mean to say.. the battery terminal on one regulator connecting to the other regulator's solar terminal? then from the battery terminal to the battery. This is like desperate solution.

Eish, anyone with a better solution. I understand the better solution is to explain these things to them, but they seem not to care!:confused:

The system is a 370watts of PV and always a 120ah battery. They use it for lights (no electricity is in this area), charging phones, TV, radio, etc.. If i bring I shut the system down.. believe me they will have to walk for 15km to charge the phone only!

Comments

  • icarusicarus Solar Expert Posts: 5,355 ✭✭✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    Your problem(s) may not just be them. YOu are talking about all kinds of loads on this system, and it is a small system. The 370 watts of PV are likely to give you ~ 6-700 watt/hours out of the system per day. The 120 ah of battery @ 50% depth of discharge (DOD) will give you ~ 720 wh of power. So every day you can just barely put in 50% of battery capacity. My guess is that you (your family are consistently drawing the batteries down too far and not giving them enough time to fully recharge..

    That 6-700 watt/hours of power will power a 100 watt TV for 6-7 hours for example, or 5 15 watt CFL bulbs for ~ 9 hours. It doesn't take long to run up a 600 wh load.

    I am not sure what you are asking, but what you want is a good Pv installation, coupled to a good charge controller, out put to an inverter with a proper low voltage shut down, such that it protects the battery bank. If you force you family to change their habits by having the system shut down before it kills the battery it might help.

    Tony
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    I don't understand how they can "not use the charge controller". Are they changing the wiring? Or is it that they ignore the information provided by it regarding state of charge?

    I can sympathize: I have told the kids "do not run the water pump without the generator if the batteries are not in float" many times. This Summer they were there for a week without me. Ever single night dead batteries by morning. Good thing I wasn't planning on keeping that set.

    Your whole system should be hard-wired. I don't know what you've got for an inverter, but the really good ones can be programmed with a shut off point and a turn on point so that if the batteries are too low there simply is no AC power available.

    Otherwise you'll have to take the batteries with you when you leave and how they get power will be their problem. :p
  • BB.BB. Super Moderators, Administrators Posts: 29,719 admin
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    I am confused... There is a solar charge controller and they are removing it and directly connecting the solar panels to the battery bank?

    Are they keeping the batteries filled with distilled water/filtered rain water?

    Are you thinking the battery is being killed by over charging (boiling battery dry)? Or by over equalization causing plate corrosion?

    I don't know--but I am tending towards Tony's thoughts that the battery is being killed by over discharging.

    A battery monitor--if they can be taught to use one--Would be a good start (assuming there is a charge controller installed too). However even a Trimetric at $152 is probably a bit expensive for such a small system.

    You could measure the usage with a $60 DC Amp*Hour / Watt*Hour meter--but that is going to require even more thought by the users... Interesting for you, but probably not as good as the Battery Monitor (these Amp*Hour meters are one-way reading devices... A battery monitor logs current in and out of the battery so you can read the battery state of charge like the gas gauge on a fuel tank).

    And what is connected to the battery bank? DC loads and/or a 120 VAC inverter? Some inverters can be programmed to turn off at a higher voltage than 10.5 volts (dead battery)--Not ideal, but may force the issue.

    In any case, assuming they are using more power than is available--Are their loads the most efficient possible (LED lights, a MorningStar inverter or other very small/efficient inverter, the MorningStar has a search mode that cuts way back on DC current if less than 6 watts of load is connected, also can use a simple DC switch to "inhibit" the inverter to save power)? Are they turning off loads (inverter shut down with no AC loads, unplugging / turning of DC loads/charger when done, etc.)?

    This is a pretty small system, and they simply may be overwhelming it with their power needs. You have a lot of solar panel on a 120 AH battery (not a bad thing if using a charge controller).

    Some charge controllers have a programmable 8-10 amp or so DC LOAD output that can be programmed to ~11.5 volts (or other settings?) to turn off the DC loads--But this is not a cheap solution and, I am sure, they would bypass as soon as you left because there is still useful power in the battery bank.

    By the way, is the 120 AH battery a true deep cycle or just a large truck battery which is dying because they are only designed to for shallow cycling?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    it seems you need to better evaluate the loads and it seems you aren't there to know what is really being drawn from the system. along this line we also don't know if all of the loads are on an inverter or the battery or both. if all is on an inverter then a watt meter is in order that can do watt hours such as a killawatt meter. once the actual loads are determined this will say if the loads are killing the battery and will help to determine a proper battery/pv system based on the power consumed.

    as to their removing the controller, have you asked them their reason for removing it as that should stay in place no matter what?
  • JakachiraJakachira Solar Expert Posts: 47
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    @Icarus :That might be a good idea, to increase the size of the panels.

    The guys disconnect the solar regulator whenever they feel like too. They think that by doing the float charging, the controller will be restricting them the power they should have. Truly speaking..these are real TV watchers... (probably 5hours during the day then 4 hours during the night (9hours of watching TV)) As long as there is power, they keep that TV on.. Power consumption of the TV (85watts) , the DVD Player consumes 35watts..Total is 120watts. connected to a 300watts Inverter.. This is their most common load and of course phones charging (may have 30 cellphones at anytime - most from rural villagers)..

    As you said I think I need to install more panels..two more 100watts panels will do for me. I will then do a permanant installation for this system.

    What i have to do is to prevent any shortage of power at anytime by increasing the size of the panels.. I usually see 22amps of solar panels on my Steca controller in the afternoon (at maximum). In full sun,one day, the panels had produced 101ah (recorded on my controller, of coz may differs from what the battery gets).
  • BB.BB. Super Moderators, Administrators Posts: 29,719 admin
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    It sounds like they may have more load than your panels can supply in a day... 30 cell phones becomes a significant load all in itself.
    • 9 hours * 120 watts total TV+DVR = 1,080 WH TV
    • 1,080 WH * 1/12 volt battery 1/0.85 eff inverter * 1/0.80 battery eff = 132 AH
    The maximum you have measured in a day is 101 AH from the solar array.

    And that is before you have even charged the cell phones.

    If they use the TV+DVR during the day, that will save the 1/0.80 (80%) battery efficiency.

    If the controller were a MPPT type, removing it could reduce the Amp*Hour output a bit. If the controller is restricting current (because the battery is 100% charged), that is just increasing the life of the battery bank by preventing over charging--It is not reducing available power because the battery simply does not have any more room to store power (it is 100% full). Yes, during the Absorb Phase, when the current is being reduced, they are losing some power (and hopefully getting more battery life).

    In the end, it sounds like you are the one paying for replacement batteries?

    I think a larger system (more panels, more batteries) to better match their loads would be helpful. As would getting a good quality hydrometer and Battery Monitor (like the Trimetric).

    A battery monitor will tell you a lot. And if this is a flooded cell battery, you can monitor with a hydrometer.

    However, if they simply don't care--Then they are going to continue to burn through batteries until the battery costs become burdensome.

    At some point, is the cost of replacement batteries going to become an issue (with them or you--depending on who is footing the costs)?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • JakachiraJakachira Solar Expert Posts: 47
    Re: HOW TO AVOID BATTERY MISUSE (while away)?
    BB. wrote: »
    I am confused... There is a solar charge controller and they are removing it and directly connecting the solar panels to the battery bank?l
    Yes, they say it "blocks power from getting into the battery" Well we know what they mean.. I have tried to explain the use of the controller to them but they don't take it serious..When i'm not there.. they just by-pass the regulator..by removing it from the circuit. There are about 4 condemned 120ah Deep Cycle batteries now. They all show signs of burning
    BB. wrote: »
    Are they keeping the batteries filled with distilled water/filtered rain water?
    I always buy sealed batteries.
    BB. wrote: »
    Are you thinking the battery is being killed by over charging (boiling battery dry)? Or by over equalization causing plate corrosion?
    They are simply cooking these batteries (my money :grr). Currently, i gave them 7a/h battery for punishment. They will have to understand
    BB. wrote: »
    I don't know--but I am tending towards Tony's thoughts that the battery is being killed by over discharging.

    A battery monitor--if they can be taught to use one--Would be a good start (assuming there is a charge controller installed too). However even a Trimetric at $152 is probably a bit expensive for such a small system.

    You could measure the usage with a $60 DC Amp*Hour / Watt*Hour meter--but that is going to require even more thought by the users... Interesting for you, but probably not as good as the Battery Monitor (these Amp*Hour meters are one-way reading devices... A battery monitor logs current in and out of the battery so you can read the battery state of charge like the gas gauge on a fuel tank).

    I have three solar regulators and one multimeter. I have a Steca PR3030 controller with an LCD display.. When sun in up.. the maximum measurements i have seen on my controller are 22amps of solar panel current, 101ah of solar panel produced in a day.
    BB. wrote: »
    And what is connected to the battery bank? DC loads and/or a 120 VAC inverter? Some inverters can be programmed to turn off at a higher voltage than 10.5 volts (dead battery)--Not ideal, but may force the issue.
    The battery is connected to the 300watts inverter (not permanently connected). I always keep the solar controller connected to the battery when i'm around.. but if i'm not around, they connect solar panels directly to the battery (i always find the system wrongly connected this way when i arrive home).

    I have two inverters..all they shut off when there is no power..so they don't over discharge the battery but they overcharge it.
    BB. wrote: »
    In any case, assuming they are using more power than is available--Are their loads the most efficient possible (LED lights, a MorningStar inverter or other very small/efficient inverter, the MorningStar has a search mode that cuts way back on DC current if less than 6 watts of load is connected, also can use a simple DC switch to "inhibit" the inverter to save power)? Are they turning off loads (inverter shut down with no AC loads, unplugging / turning of DC loads/charger when done, etc.)?

    This is a pretty small system, and they simply may be overwhelming it with their power needs. You have a lot of solar panel on a 120 AH battery (not a bad thing if using a charge controller).

    Some charge controllers have a programmable 8-10 amp or so DC LOAD output that can be programmed to ~11.5 volts (or other settings?) to turn off the DC loads--But this is not a cheap solution and, I am sure, they would bypass as soon as you left because there is still useful power in the battery bank.

    By the way, is the 120 AH battery a true deep cycle or just a large truck battery which is dying because they are only designed to for shallow cycling?

    -Bill

    -Bill

    I always provide a correct new sealed deep cycle battery. After one or two weeks i recieve an SMS from them "battery no longer lasts for 20minutes when fully charged.. can you bring a new one?" Eish!

    I think by increasing solar panels that may solve my problem..At night they mostly watch Movies.. TV & DVD Player (85watts and 35watts). 2 DC lamps of 2.5watts each they use them for 3 or 4 hours (i connected these to the solar controller load terminal, but since they take it out, i assume they connect them directly to the battery).

    My solar power system serves a lot of people by charging mobile phones. The closest place with grid power to charge phones is 20km away..and no transport.
  • JakachiraJakachira Solar Expert Posts: 47
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    Thanks, for the quick reply, BB

    The issue now is of replacing batteries in 1 or 2 weeks. They are very much exepnsive this side. $200 for a good 105ah solar battery .
  • BB.BB. Super Moderators, Administrators Posts: 29,719 admin
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    The problem with more panels and no controller--they may over voltage the battery (over 15.0 volts). And shutdown or ruin the inverter (and any DC direct loads like 12 VDC cell phone chargers). And possibly severely overcharge the AGM battery, causing it to vent electrolyte without the charge controller (if they do ever turn off enough loads to properly charge the battery in the first place--which I am not sure).

    They probably are not killing the battery in 1 week, they probably are simply using more power than the solar panels can produce (I said that in the post just before yours--but you probably have missed it as we posted at the same time).

    My fear is that they will not take care of the battery as long as they are not financially responsible.

    A battery monitor is pretty much a requirement for managing a Sealed Battery Bank (no hydrometer)--But I am not very hopeful that they will learn as long as you are supporting them.

    I know that in some parts of the world, charging cell phones can be a significant source of money... Any chance of them making a self supporting business out of it? If they had to pay for their own batteries--They may not be so cavalier about maintaining and using the system within its limits.

    My fear is that they will never accept the limitations that they cannot watch unlimited amounts of TV and charge huge numbers of cell phones with the system they have... And if you grow the system, they probably will not take care of it either--just costing you even more money to replace larger numbers of batteries.

    How do you educate and teach them to care? And turn of the TV when the battery bank needs recharging... I am not sure you can (human nature, human engineering problem).

    You can make a system with a Battery Monitor with a programmable output that can turn the output off the loads at 50% state of charge and turn it back on when the batteries are at 90% state of charge. But you would have to build a block house to lock the system up and not give them the key--or they would simply bypass that too... :confused:

    You could backup the system with a generator--but the cost of fuel is probably prohibitive.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 29,719 admin
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    By the way, do they have good quality flooded cell deep cycle batteries and a source of distilled water (or filtered rain water) to keep the batteries filled?

    It would be cheaper than AGM and even if you have to replace the batteries once a year because of abuse/poor water--It would be cheaper than AGMs.

    But then you have the human factor and requiring them to properly maintain the flooded cell battery...:cry:

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • icarusicarus Solar Expert Posts: 5,355 ✭✭✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    Wire a large cap to the connections so they get a good zap when they try to undo the controller!

    Tony
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    If not a cement block house, at least a metal box with a good lock. Everything inside with the PV output running in and extension cords running out (120 V and 12 V).
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    the basic thing a controller does is prevent too high of a voltage from appearing on a battery and thus prevents overcharging. this may also prevent damage to some electronics from overvoltage conditions. in the event of a high load current being presented, the voltage will drop to lower levels on their own so the controller is not doing anything under those circumstances. they need to leave it connected to prevent an overcharge on the battery and it stands to reason that if there is that much current available to overcharge a battery that they don't have loads that would require more power at that point.

    now i'm not going to call them dumb as they know enough to disconnect the controller and free wire the pv to the batteries, but they know just enough to be detrimental to the system. if they knew nothing they'd have left it all alone and if they knew allot this posting of your concerns would not be here. they think they know better than you at your expense so there is a train wreck coming that is unavoidable here even if you get the perfect system for your load requirements. if it were me i'd shut it down when i left, but as i said, they know enough to be able to reconnect it and destroy it.:cry:
  • Ralph DayRalph Day Solar Expert Posts: 892 ✭✭✭✭
    Re: HOW TO AVOID BATTERY MISUSE (while away)?

    Tough Love approach required:grr. Lockable room or box for components, hide or lock up the batteries when you leave (leave them with the last set they screwed up). Take up a collection for ruined equipment (from users, not us :cool:)

    Ralph
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