# Newbie looking for help!

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Registered Users Posts: 18
Hi all, first off great site! I have been learning at the most alarming rate my non-mathematically mind can learn. With that said I am not mathematically inclined nor an electrician by any means. So with that out of the way here are my questions and a little background info.

My wife and I wanted to leave the city life behind us. We found a cabin an hour north of Las Vegas and decided to make it our new home. The home is in a town that is completely off grid. Our set-up was already there when we purchased our home.

Here are the specs:
24Volt
12 LS16 series Trojan batteries in 3 banks of 4 New in 09
Trace engineering 2.6 KW inverter
APT PowerCenter3 charge controller
12 Kyocera 51.0 watt panels in two arrays of 6 (two have broken glass)
DeWalt 6000 KW generator

I know the next question you are going to ask is our daily usage. Well, to be honest I haven't figured it out yet. I didn't want to compare our usage in town to now because I'll be the first to admit that the laptop stayed plugged in along with the coffee maker and of course the lights were left on in the other room when we weren't there.

Anyways, I plan on removing my two broken panels from the one array and then move my top panel from the other array to the other side so I am running 5 and 5.

I know I will need more panels but the funds won't allow that right now. So here is my basic question that I have yet to find a definitive answer on.
When I push the button on my trace inverter to see battery voltage I get a number generally .5 higher than the number displayed on my charge controller. Being cautious I always go with the lower number to determine my state of charge. I know 25.6 is full charge. My question is... what is the magic number that I should be watching for that tells me my batteries are at half charge and I better fire up the generator? Eventually I am looking at getting a new charge controller that allows me to monitor the battery voltage from inside the house. I also would like to have the system be able to eventually turn the generator on automatically when I hit a certain battery voltage.

Sorry I know this is long winded, but I do appreciate your time and responses.
Dan
«1

• Solar Expert Posts: 9,583 ✭✭✭✭✭
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Re: Newbie looking for help!

You have quite a challange to adjust to. You have 10 working panels, and I hope strings of 5 are enough to charge your batteries.
510W of pv turns into about 408w when you take of 20% for non-labratory conditions. x 4 hours of good sun, gives you 1.632 KWh daily harvest in winter. Add in battery recharge losses and inverter losses, and you will be lucky if you can burn 1KW daily, and have the sun recharge the batteries, w/o having to fire up the generator.

When you were in escrow, did you check battery voltage and water levels ?

Unattended low batteries, or dry plates usually is bad news.

Welcome to the solar club, where you can get 6 different answers from 4 different people.
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 ,

• Registered Users Posts: 18
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Re: Newbie looking for help!
mike90045 wrote: »
You have quite a challange to adjust to. You have 10 working panels, and I hope strings of 5 are enough to charge your batteries.
510W of pv turns into about 408w when you take of 20% for non-labratory conditions. x 4 hours of good sun, gives you 1.632 KWh daily harvest in winter. Add in battery recharge losses and inverter losses, and you will be lucky if you can burn 1KW daily, and have the sun recharge the batteries, w/o having to fire up the generator.

When you were in escrow, did you check battery voltage and water levels ?

Unattended low batteries, or dry plates usually is bad news.

Welcome to the solar club, where you can get 6 different answers from 4 different people.
Thanks I needed that laugh.

I know we have some adjustments to do and we have been doing very well about turning off lights and charging electronics when the generator is on. I did check water levels and battery voltage when in escrow. Water level was good and they were always charged because nothing was drawing on them. The people before us only were only part timers at the home.
• Banned Posts: 17,615 ✭✭✭
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Re: Newbie looking for help!

Right. First problem: you have no place near enough panel to recharge 960 Amp hours of tall case Trojan L16's. These really need the peak 10% charge current, i.e. 96 Amps. To get close to that on a "24 Volt" system:

96 * 28.4 charging Volts = 2726 @ 80% efficiency = roughly 3400 Watts of panel.

You've got 12 @ 51 Watts = 612 @80% efficiency = 489 Watts usable. Not including broken panels or extra derating that may be required for your particular site. It's not good. How much current do you see from your charge controller? 17 Amps at best? That would do for one bank of the L16's maximum. Possibly not even that.

So you definitely should be running the generator so as not to waste those nearly new batteries. I'm not familiar with that charge controller so I don't know if it has any read out or even if it's a proper 3-stage unit. Check out the battery FAQ's for starters: http://www.windsun.com/Batteries/Battery_FAQ.htm

A "24 Volt" system should Absorb at about 28.4 and should Float at 27.6. The absolute lowest you can take these would be 21 Volts, and that would be pretty rough usage (shorter battery life).

Get yourself a hydrometer and take Specific Gravity readings on all the battery cells, "at rest" (nothing going in or out for at least three hours). You need to know what state those batteries are in if you're going to preserve them.

And you are going to need more panel. Not necessarily 3600 Watts; you may find it easier to cut your usage down and not need to run such a big battery bank.
• Solar Expert Posts: 5,436 ✭✭✭✭
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Re: Newbie looking for help!

Do some "real life" load calcs (estimates?) to determine whether or not you really need so much battery capacity.

A common mistake people make (myself included) is assuming that bigger battery banks are better. What usually happens is people think they have lots of battery,ergo they don't need to worry about charging as much, when in fact the reverse is true,, a 'Coot says.

Tony
• Solar Expert Posts: 9,583 ✭✭✭✭✭
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Re: Newbie looking for help!
I know 25.6 is full charge. My question is... what is the magic number that I should be watching for that tells me my batteries are at half charge and I better fire up the generator? Eventually I am looking at getting a new charge controller that allows me to monitor the battery voltage from inside the house. I also would like to have the system be able to eventually turn the generator on automatically when I hit a certain battery voltage.

Sorry I know this is long winded, but I do appreciate your time and responses.
Dan

There is no good way to measure battery voltage under load. The best way to do what you ask, is to use a amp hour totalizer, which counts amps in vs amps out of the battery. When it caculates you have used half, you will need a relay and a Generator starting Module, to fire up the genny. And these aint cheap.
Meters/Monitors/Totalizers are here : http://www.solar-electric.com/metersmonitors.html

Use the search fuction at the same site for Generator & Starting to filter out the modules that can, or with optional parts, auto start a genset.

Hope this helps.
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 ,

• Registered Users Posts: 18
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Re: Newbie looking for help!

Mike thanks for the link. I need to get something because telling my wife every night "we're going dark" isn't going to last much longer while I run out and check the numbers! Coot thank you for the math. When I see it laid out in front of me I can understand it but when I have to crunch the numbers myself I am slower than slow with a bit of confusion mixed in!. Thank you for answering my questions and I will continue researching and reading here. Thanks again and to the guy that pissed on my post next time start your own thread:p
• Registered Users Posts: 18
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Re: Newbie looking for help!

Thank-you everyone else also. I am going to take specific gravity readings this weekend and will post back what I find. Have a Happy Thanksgiving!!
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Re: Newbie looking for help!

I moved all of the off-topic commentary over to Sr Guy's original thread:

The "perfect" 2500W system--Suggestions?

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 9,583 ✭✭✭✭✭
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Re: Newbie looking for help!

One way to get the most out of the system, is to fire up the genset every morning for a half hour or more, as needed to get the batteries to 80% full), and use it to bulk charge the batteries, and then let the solar top them up the rest of the day. Generator at night while you run the microwave, is OK, and the batteries will appreciate it.
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 ,

• Registered Users Posts: 18
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Re: Newbie looking for help!
mike90045 wrote: »
One way to get the most out of the system, is to fire up the genset every morning for a half hour or more, as needed to get the batteries to 80% full), and use it to bulk charge the batteries, and then let the solar top them up the rest of the day. Generator at night while you run the microwave, is OK, and the batteries will appreciate it.

Sounds good. Kind of what we do now. We fire it up every morning to make coffee. Coming home and lookingat the numbers, in the dark and no load, I can tell if we had a sunny day or not. Definitely time to get some more panels and a trimetric. Thanks again
• Solar Expert Posts: 5,436 ✭✭✭✭
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Re: Newbie looking for help!

There is no substitute for more PV. Time shifting the loads to times of good sun helps too. Mike's idea of running the gennie in the AM is a good one, most folks wait and get sucked into running it in the afternoon, and as a result not very efficiently.

T
• Registered Users Posts: 18
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Re: Newbie looking for help!

Well, I finally had a chance to check my batteries with a hydrometer. Numbers ranged from the lowest being 1.270 to the highest being 1.300 on the hydrometer. It was 50 degress when I checked the batteries. According to Trojans website I had to subtract .004 for every ten degress below 80. This made my number range from 1.258 to 1.288. Trojan recommendeds a range of 1.27 to 1.284. So, I equalized my batteries. Ran the generator all day, 7 hours. Went out and I could hear the batteries bubbling. I have to check them again now that I have equalized.

From your experience how often do you equalize?

I also ordered a Trimetric monitor so I can keep a closer eye on what's really going on. Yay, no more turning everything off and going out and checking the numbers!
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Re: Newbie looking for help!

For equalization--you should check the batteries every 30-60 minutes... Once the cell(s) stop increasing specific gravity, then stop equalization.

Equalization is actually pretty hard on a battery bank and you only want to do it when it is needed (Trojan says if the spread is more than 0.030 specific gravity from low to high cell). Ideally, you want to write down the SG values after your equalization is complete so you know the 100% charged level from your battery bank.

Check the water levels before you equalize (covering the plates), and add water to normal levels after equalization (overfilling then equalizing can be a big mess).

Otherwise, from what I have read here--maybe 3-12 times per year (once a month would be on the high end). And equalization should only take 30-120 minutes (depending on how far out of balance your cells are and how much current you are supplying--typically ~5% of the 20 Hour battery capacity rating--i.e., a 100 AH bank would be equalized at 5 amps).

Trojan Battery 20 page Maintenance FAQ (PDF).
Trojan Battery Maintenance FAQ in español (PDF).
Deep Cycle Battery FAQ
http://www.batteryfaq.org/
www.powerstream.com/SLA.htm
BB. wrote: »
Eric/Westbranch posted a link to a 1922 battery repair manual. A very interesting read and look back almost 90 years at technology and mass production (near the end are some factory photographs).

THE AUTOMOBILE STORAGE BATTERY ITS CARE AND REPAIR

Despite the title, also includes information on storage batteries too (Farm Lighting Batteries).

There are others with much more experience than I with battery banks here--They can give you some more information.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 334 ✭✭
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just a couple of points:

On the SG readings, the temperature compensation is for the temperature of the electrolyte, NOT ambient air temps. Some hydrometers come with a thermometer with temperature compensation values clearly visible, which can be handy.

If you were taking voltage readings just after turning all the lights off, then your voltage readings really wont tell you much. In order to take "at rest" voltage readings the batteries need to sit "resting" for a while, at bare minimum 6hrs to give a rough estimate and probably closer to 24 hrs to give a really accurate measure. Lucky for us we don't really need to know down to a fine percentile just how charged or discharged our battery bank is; being within 10% is probably more than we need to worry about and even just really rough estimates of 20% or so should be enough to tell us when to turn the generator on. The big numbers to watch are when nearing the 50% mark, and making sure that the batteries do get a FULL 100% charge from time to time (particularly important after any deeper discharges)

As for voltage under load readings (which are FAR more relevant to us than "at rest" readings which we rarely have), I'd try the following:

On EQ'ing, in general you probably want to EQ when one of the following is the case:
-the batteries have not had a really full charge in a few weeks
-after finishing normal absorb cycle and exhibiting a full charge, while the SG levels are notably lower than full
-if the SG levels vary wildly from cell to cell, typically spreading more than 0.03 from high to low

There are various levels of Equalizing a battery bank as well, and some range of opinions on how often to do them. In general what you'll hopefully be doing is typically termed Opportunity Equalizing; where you're simply giving the batteries a boost to completely recharge any low cells that haven't been getting quite all the way charged up on your regular charging routine (which is often the case in a PV charging set up). This you probably want to do roughly once a month, or as needed.
Corrective Equalizing is a much bigger deal, and a lot harder on batteries, and should be avoided if possible by taking good care of your batteries. It will likely involve many hours or even days of high voltage charging in an attempt to restore a partially sulphated battery... not a fun process.
• Banned Posts: 17,615 ✭✭✭
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Re: Newbie looking for help!

Couple of observations/points from an old guy whose been using tons of different types of batteries for several decades.

1). Hydrometer readings are relative. Yours may not read the same as the manufacturer's even at the same temp on the same battery. It is best to take readings when you first put the battery in to service and compare subsequent readings with the same hydrometer to that. Likewise, it's relative between cells. Equalization requirements are so much a matter of a particular number as of a difference between cells.

2). Never automatically equalize batteries unless it is an "unattended" installation. Like Bill said, running the Voltage up and keeping it there for an hour is hard on the battery. Check the SG per cell, and if the difference is greater than 0.010 (my pick, others my vary) equalize once (one hour) and recheck. Remember that bubbling batteries can put bubbles on the hydrometer float, giving a false reading. Ideally you should let the battery rest at least an hour before taking another reading.

3). Hydrometers are not perfect. Eyesight is not perfect. Batteries are not perfect. The world is not perfect. Sometimes it's more art than science. Apply this info accordingly.
• Solar Expert Posts: 334 ✭✭
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Re: Newbie looking for help!
3). Hydrometers are not perfect. Eyesight is not perfect. Batteries are not perfect. The world is not perfect. Sometimes it's more art than science. Apply this info accordingly.

This may well be THE most accurate statement I've ever read on how to read and interperate the numbers on batteries! I can most certainly say from personal experience this has been the case for me and my care and tending of batteries (which is still VERY much a learning process). The hydrometer in particular has been especially problematic; so much that I will ultimately blame my bad luck with various hydrometers 100% for the premature death of my batteries :-) ... whenever my batteries finally give out and die.
• Registered Users Posts: 18
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Re: Newbie looking for help!

Wow, thanks for the write ups and responses! The batteries were at rest for at least 6 hours. No input, no load. I will check the SG again next rest time I get in. So do you guys check every cell on every battery when you are testing from time to time, or do you randomly check different cells.

Another note, if you go out of town for a week do you let the PVs still charge the batteries or do you shut it down. I only ask because the people I bought the house from were part timers and everytime I went to the house, during escrow, the batteries were bubbling because there wasn't a load on them.

Good news my Trimetric meter came today, so hopefully this will help me be able to use the batteries mroe effectively instead of running the generator so much because I am fearful of draining them too much.
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Re: Newbie looking for help!

Well I check every cell every time, about twice per month. Otherwise you might not notice if one cell has suddenly suffered a catastrophic failure (e.g. SG of 1.100 but the whole battery reads 12.65 Volts - one cell shorted, the others over-charged).

If you go away for any significant length of time turn off the inverter and any other DC loads (unless it is something critical) but leave the panels & charge controller connected to the batteries. That way when you come back they'll be fully charged. With no usage, there shouldn't be any long Bulk/Absorb time on them and there should be no significant loss of water. If there is, then maybe your charge parameters are off - like too high Absorb of Float Voltage or too long minimum Absorb time.
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Re: Newbie looking for help!

Yea, check the charging and float voltage at the battery bank... At 77F--you should be around 14.2-14.5 volts charging, and 13.2-13.7 volts floating (floating is after the battery is 100% charged at 14.5 volts, the controller drops back to 13.6 volts or so to keep the batteries charged, but not bubbling).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 10,300 ✭✭✭✭
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Re: Newbie looking for help!

this was a system that came with the property and the condition of those batteries would be something that comes to mind that as far as i can tell you did not sufficiently test to answer that question. for instance you said it was always bubbling when you got there and there weren't any loads on it. if there happens to be a bad cell in one of those batteries it would want to try and continually charge it. an at rest voltage that is under the general area one would expect it to be at could say there's a bad cell or even more than one bad cell. i don't recall at this time if you said there were any batteries in parallel in your bank or not, but in a parallel arrangement the battery with the bad cell would constantly drain off the power to the other good batteries and thus destroy them too. if cell levels are good, sg levels look good, and the voltages of the batteries look good (if parallel then disconnect the batteries and measure individually) then the only thing left may be the question of their capacity which one can get a good idea of just by using them, but a load test is more exacting.
• Registered Users Posts: 18
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Re: Newbie looking for help!
Well I check every cell every time, about twice per month. Otherwise you might not notice if one cell has suddenly suffered a catastrophic failure (e.g. SG of 1.100 but the whole battery reads 12.65 Volts - one cell shorted, the others over-charged).

If you go away for any significant length of time turn off the inverter and any other DC loads (unless it is something critical) but leave the panels & charge controller connected to the batteries. That way when you come back they'll be fully charged. With no usage, there shouldn't be any long Bulk/Absorb time on them and there should be no significant loss of water. If there is, then maybe your charge parameters are off - like too high Absorb of Float Voltage or too long minimum Absorb time.

Good to know, Thanks.
• Registered Users Posts: 18
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Re: Newbie looking for help!
BB. wrote: »
Yea, check the charging and float voltage at the battery bank... At 77F--you should be around 14.2-14.5 volts charging, and 13.2-13.7 volts floating (floating is after the battery is 100% charged at 14.5 volts, the controller drops back to 13.6 volts or so to keep the batteries charged, but not bubbling).

-Bill

I did notice the light on my charge controller bouncing in and out of Charging and stopped modes while equalizing. Are you checking the volts on your charge controller or a volt meter at the battery?
• Registered Users Posts: 18
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Re: Newbie looking for help!
niel wrote: »
this was a system that came with the property and the condition of those batteries would be something that comes to mind that as far as i can tell you did not sufficiently test to answer that question. for instance you said it was always bubbling when you got there and there weren't any loads on it. if there happens to be a bad cell in one of those batteries it would want to try and continually charge it. an at rest voltage that is under the general area one would expect it to be at could say there's a bad cell or even more than one bad cell. i don't recall at this time if you said there were any batteries in parallel in your bank or not, but in a parallel arrangement the battery with the bad cell would constantly drain off the power to the other good batteries and thus destroy them too. if cell levels are good, sg levels look good, and the voltages of the batteries look good (if parallel then disconnect the batteries and measure individually) then the only thing left may be the question of their capacity which one can get a good idea of just by using them, but a load test is more exacting.

Batteries were brand new the summer before I bought the property. There are 12 LS16 Trojans. 3 strings of 4. I tested all the cells and there was only a max difference of .010 between the cells. I don't think there are any bad cells and I understand what you are saying a bout a bad cell draining off the other ones. I guess I equalized wrong. (I thought getting the batteries bubbling was a good thing to keep them from sulphating.) I will be installing my Trimetric 2025 this next week and I should have a better handle on my batteries.

My inverter and charge controller are from the early 90's and are working for now, but eventually I will replace the controller first. Right now I have a .9mV draw on my load amperage display that is always there. I'm guessing this is from powering the inverter or a ghost load. My inverter has little knobs to dial in parameters but I don't think it's very accurate because it's just a range. I have more panels to add first and I guess everything will fall into place later.
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Re: Newbie looking for help!

In the end--it is the proper voltage at the battery bank that matters (corrected for temperature if your bank is way different than ~77F/25C.

Always double check your readings with any voltmeter... We have had a few times when failing DMM's or DMM's with weak batteries have caused some very strange readings (not right, but not 100% wrong in a consistent manner).

It is possible that a charge controller with too small of controller to battery wiring (or too long), bad connections, interference with other DC loads (Battery de-Sulphators and some AC inverters have been known to confuse a couple Outback charge controllers, other charge controller+inverter DC ripple noise issues have been reported before with older Blue Sky controllers), etc. can confuse the charge controller.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 18
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Re: Newbie looking for help!
Couple of observations/points from an old guy whose been using tons of different types of batteries for several decades.

1). Hydrometer readings are relative. Yours may not read the same as the manufacturer's even at the same temp on the same battery. It is best to take readings when you first put the battery in to service and compare subsequent readings with the same hydrometer to that. Likewise, it's relative between cells. Equalization requirements are so much a matter of a particular number as of a difference between cells.

2). Never automatically equalize batteries unless it is an "unattended" installation. Like Bill said, running the Voltage up and keeping it there for an hour is hard on the battery. Check the SG per cell, and if the difference is greater than 0.010 (my pick, others my vary) equalize once (one hour) and recheck. Remember that bubbling batteries can put bubbles on the hydrometer float, giving a false reading. Ideally you should let the battery rest at least an hour before taking another reading.
3). Hydrometers are not perfect. Eyesight is not perfect. Batteries are not perfect. The world is not perfect. Sometimes it's more art than science. Apply this info accordingly.
:D

While equalizing I noticed my charge controler was clicking from charging to stopped. My question is if I am running the generator say to do laundry or work in the shop with grinders, saws, shop vac, etc watching the big screen watt hungry tv, and it is charging the batteries at the same time am I hurting the batteries. Or, is the charge controller stopping them from overcharging? I don't know the more I think I begin to understand the more confused I get.
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Re: Newbie looking for help!

For the most part, you can parallel different controllers to one battery bank (assuming proper electrical connections).

The battery charging voltage will end up being set by the controller with the highest output voltage...

If your solar charger is a 3 stage type--and is currently set to "float" at 13.6 volts... And your AC charger is a 2 stage type that is set for bulk/absorb charging at 14.4 volts--the AC charger will simply take the battery to 14.4 volt.

If both are 3 stage chargers--You still will have the condition where charger A has decided on 13.6 volts and charger B is still in absorb at 14.4 volts for another hour.

When the batteries are not fully charged, both controllers will supply their maximum rated current into the battery bank until battery reaches the target voltage.

You may be able to set the chargers for different Absorb voltage... Set the Solar to 14.5 volts and set the AC charger to 14.2 volts. Then the AC charger will only charge if the battery voltage is low and there is insufficient solar for charging.

Or you can set the genset to 14.5 volts for maximum charging current (start the genset first thing in the morning before ~9am) to get the most energy from the genset into the battery bank quickly (gensets are more efficient if loaded to ~>50% of rated load). Then shutdown the AC charger/genset and let the solar panels finish up charging the rest of the day.

The above are just a couple of examples you can use... Some of this depends on how often you use your genset and how much loading you have. Normally--I like to reduce genest runtime and increase fuel efficiency--Generally this means maximizing battery charging current (charging discharged bank up to ~80-90% state of charge with near 100% of available charger current / generator maximum loading) and letting the solar array finish of the charging (say after 2-3 days of no sun).

Make sense?

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 334 ✭✭
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Re: Newbie looking for help!
Batteries were brand new the summer before I bought the property. There are 12 LS16 Trojans. 3 strings of 4. I tested all the cells and there was only a max difference of .010 between the cells. I don't think there are any bad cells and I understand what you are saying a bout a bad cell draining off the other ones. I guess I equalized wrong. (I thought getting the batteries bubbling was a good thing to keep them from sulphating.) I will be installing my Trimetric 2025 this next week and I should have a better handle on my batteries.

Not sure what you mean about Equalizing them wrong. Sounds like they maybe just didn't actually need equalizing. Some bubbling is normal when absorbing or EQing, no bubbling at all while charging would indicate insufficient charging, constant vigorous bubbling for hours and hours on a regular basis will shorten the batteries lifespan. If the difference between all cells was within .010, that's really good particularly with 3 parallel strings; mine never get that close even after EQ'ing :-(

Think of EQ'ing as a way to insure that all cells get returned to 100% on a semi regular basis; meaning don't obsess on having to get all cells completely full every single day, but don't go months at a time with some cells only getting up to 80-90% full either. Usually in regular cycling you'll find that there are imbalances in the charging and discharging, thus some cells end up getting full early and some may not quite get completely full. If this type of cycling were to continue for extended periods of time the imbalances can grow, and eventually this will lead to some cells working much harder and having their life span shortened while other cells will begin to sulphate. Hence there is some range of opinions on exactly how and when to EQ, but the idea is the same: use it as a tool when needed to balance and recharge all cells, but only if/when needed.
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Re: Newbie looking for help!

Another thing to watch for is battery water usage. No water usage month after month--you probably are undercharging.

If you are using a lot of water (electrolyte levels near plate surface every month)--you probably are overcharging / equalizing.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 334 ✭✭
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Re: Newbie looking for help!
:D

While equalizing I noticed my charge controler was clicking from charging to stopped. My question is if I am running the generator say to do laundry or work in the shop with grinders, saws, shop vac, etc watching the big screen watt hungry tv, and it is charging the batteries at the same time am I hurting the batteries. Or, is the charge controller stopping them from overcharging? I don't know the more I think I begin to understand the more confused I get.

Sometimes it can be a bit tricky/buggy when utilizing more than one charging source at a time. I forget which chargers do you have? One issue that I've had from using the method that Bill suggests (which is in theory the ideal way to utilize a generator), is that if I let the generator fill the batteries a bit too long is that the PV charge controller will think that the batteries are completely full and stop charging, and then go into float after the generator is turned off. This means that I have to manually reset the charge controller, or sometimes tell it to "EQ" while I turn the EQ voltage setting to my actual absorb voltage. One thing that helps a bit with this is to set the absorb voltage setpoint slightly lower on the AC/DC charger than on your PV charge controller... if possible.
• Solar Expert Posts: 10,300 ✭✭✭✭
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Re: Newbie looking for help!

just to clarify, it is good to have the bubbling to mix the electrolyte, but that's while charging a battery that is not 100% soc. to do this with a battery that is charged already is over charging it and it will need water much more often.