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gcrank1
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# Posted: 14 Nov 2021 13:54 - Edited by: gcrank1
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If you read voltage right after charging you will get a false top charge. The bank has to sit At Least a few hours and pref overnight to settle down to get an accurate read.
If you read voltage during and right after usage you will get a false low. It, again, needs to sit a bit to settle in after discharging.
Starting out with fully charged bats, running a bit, then charging off the gen, over and over, is not going to tell you how well that bat bank is really performing.
I also think using both quads paralleled at this point was premature. Each quad should be 'performance tested' on their own, proven sound, then paralleled.
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bc thunder
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# Posted: 14 Nov 2021 14:53
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I have done load and hydrometer tests at the same time, over and over. Before I hooked them up, right after, several times during the evening, and right before bed. First thing this morning, And then twice more today. I can see nothing wrong. One battery on the hydrometer test is at 12.5, and all others at 12.6 but I think that OK. They are both in the 100% reading.
Am I missing something, is there something you would do other than that GC?
Thanks
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bc thunder
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# Posted: 14 Nov 2021 14:56
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This inverter shuts down automaticly at 21v
I started the gen to trick the inverter into reading 25v
After it runs for 10 mins I can turn it off and continue in battery mode.
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bc thunder
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# Posted: 14 Nov 2021 15:01
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I ran the gen during the hockey game to make sure there is full power in the batteries for sure. I don't want them to freeze as we are -10c at night now.
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bc thunder
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# Posted: 14 Nov 2021 17:04 - Edited by: bc thunder
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hydrometer reading 1250
but
load test reading 6.1v
not sure which I should be going by???
Anyone know?
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gcrank1
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# Posted: 14 Nov 2021 17:26
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12.5-12.6? hydrometer? reading on 6v batteries 
Decimal pt off?
From what I see online 6v GC bats should read 1.275 Per Cell on a fully charge bat that has been off the charger for 'some hours' and has had the 'surface charge' used off the top with a load for a few minutes.
How can you do a load and hydrometer test at the same time?
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bc thunder
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# Posted: 14 Nov 2021 17:30
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Thanks GC, got it. Your the best.
I will disconect 4 tomorrow run the test, and 4 the next.
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ICC
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# Posted: 14 Nov 2021 18:35
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Quoting: gcrank1 From what I see online 6v GC bats should read 1.275 Per Cell on a fully charge bat that has been off the charger for 'some hours' and has had the 'surface charge' used off the top with a load for a few minutes.
1.265 to 1.275, corrected for temperature. It may vary slightly between different battery manufacturers.
When using a hydrometer to test the state of charge there is no need to wait for the 'surface charge' to dissipate. That only applies to voltmeters. The hydrometer measures the specific gravity of the electrolyte. Temperature affects the specific gravity.
One thing that could possibly throw off your readings is hydrogen or oxygen bubbles that form during charging. If bubbles cling to the surface of the float it could ride too high. That is easy to eyeball though and to use a finger thump to dislodge.
Once again I'll mention the Hydrovolt hyrometer as it has temperature compemsation built in. No need for adjusting the float numbers.
A voltage reading taken during a load test is not going to give you any idea of the state of charge. The voltage will be lower than a voltage reading taken if that battery is left to sit, un-used, for a couple of hours. If it is a big load one can watch the voltage rise almost immediately as the load is disconnected.
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gcrank1
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# Posted: 14 Nov 2021 18:51 - Edited by: gcrank1
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The hydrometer should have come with instructions, if not, look up online how to use one.
Imo, with each bat charged and rested, and the surface charge 'burned off' with something running then shut off is when you do the hydrometer test of each cell, each 2-3 times to average then flush the tool and do the next. Notes for all.
Once done like that you dont need to repeat it right away. Not until you have done a defined discharge (-x-amps draw over -y- hrs) to a voltage point; ie, what 50%soc for 24v system with FLA bats is supposed to be
Ive no idea what your load test is like.
Fwiw, the load tester my friend loaned me was for 12v, has a big resister?, anyway, with nothing else drawing (I unhooked my bats) and it hooked up one bat at a time, and turned it on for x seconds (instructions on the case). The heavy load shows if the battery has only a surface charge or a real charge. If surface it can read ok on voltage but have no beans. I had two bats that had seemed good with the voltmeter but Sank right away on the scale under load.
I should mention that I had symptoms not unlike yours, a bat-bank of 4x100+ah 12v bats = 400+ah's, or so I thought; they just didnt give me the hours expected of use. Well, the load test showed why, those 2 weak bats were sucking the 2 good bats down.
Once I pulled the bad bats out of the mix I got waayyy better performance from just the 2 remaining than I had with all 4.
All these testing tools and the process analysis is defined and in order; that is, Must be followed or the results dont mean anything.
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bc thunder
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# Posted: 14 Nov 2021 19:04
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Thanks ICC
I have been using it wrong, but did notice the bubbles and high float.
Since GC set me straight I have been on you tube, and that hydro volt caught my eye. I didn't know there was a few to choose from. I unfortunatly got the crappy one. I'll try to get that one tommorrow in town when I'm replacing my volt meter that quit on me today.
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ICC
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# Posted: 14 Nov 2021 19:53 - Edited by: ICC
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Quoting: gcrank1 Imo, with each bat charged and rested, and the surface charge 'burned off' with something running then shut off is when you do the hydrometer test of each cell
Why? (If it makes one feel better, go ahead, no harm done, but it is unnecessary for hydrometer use.
Again, with a hydrometer test, you are testing the specific gravity of the electrolyte, actually measuring the concentration of the sulfuric acid. As the battery charge is depleted sulfur comes out of the solution and is deposited on the negative plates. That lowers the specific gravity of the electrolyte (makes the fluid lighter)
A surface charge is a phenomenon that occurs with lead-acid batteries while charging and reading voltages. The charging does not instantly affect the entire thickness of the lead plates. The charge builds on the surface and then "seeps" into the subsurface materials of the plates. So when you stop charging and read voltage right away the voltmeter senses the highest voltage off the plate surfaces. Hence the name "surface charge" Given a little time the surface charge spreads into the entire plate and that lowers the voltmeter reading. The specific gravity reading will not change solely from burning off a surface charge. So there is no need to burn off the surface electrical charge when using a hydrometer. Just watch out for the bubbles and correct for temperature as or if needed.
The effect is similar to what happens if a piece of steel is heated with a torch flame. The metal near the surface flame contact point will be hotter than the rest of the steel. With the flame removed heat continues to spread throughout the steel piece..... Not the best analogy but the best I can do off the top of my head.
Rinsing is good after all the readings have been made on all the cells, but no need to rinse between individual cells.
Do start a logbook. Using a hydrometer is kind of a pita, so I believe it pays dividends to record the readings. After some use, if a cell is going bad you will see the change in lower S.G. readings and not have to trust memory or try to remember which cell. I number my batteries and then count the cell numbers from positive to negative.
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gcrank1
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# Posted: 14 Nov 2021 20:19
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Thx ICC, that will make a complicated, labor intensive, pain of a proc a bit simpler 
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ICC
Member
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# Posted: 14 Nov 2021 20:54
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I can't say that I miss the cell reading with the hydrometer, since installing the LFP a few years back. House, cabin, bus/rv. 
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bc thunder
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# Posted: 15 Nov 2021 09:08 - Edited by: bc thunder
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I'm tring to see how to convert the temp / gravity on hydrometer test.
cell1 1255
cell2 1260
cell3 1260
-4c
load test 6.7 to 6.1
I'm on you tube now, but if anyone can show.....
thanks
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bc thunder
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# Posted: 15 Nov 2021 09:27
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OK I think the cells are good
1.255 1.260 1.260
1.255 1.260 1.260
1.245 1.245 1.245
1.250 1.250 1.260
Is the 1.245 ok???
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gcrank1
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# Posted: 15 Nov 2021 10:03 - Edited by: gcrank1
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Add or subtract four points (.004) to the reading for every 10*F/6*C above or below 80*F/27*C
You do not want more than 50 pts (.050) variation between any cells or there is a cell problem.
I think the 1.245 is about 75% soc,
the 1.250 about 80% soc.
Your best reading cells are only 1.260, thats about 85% soc.
So, your bank of 4 bats is ranging between only 75 to 85%. Bingo-problem.
If those had been fully charged within the last couple days on a grid charger to be for sure and certain it appears they cant hold a charge. That also means they cant discharge much before hitting the wall.
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bc thunder
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# Posted: 15 Nov 2021 14:23
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so a super slow charge, or are these garbage?
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bc thunder
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# Posted: 15 Nov 2021 14:24
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just subtracted .12 from those tottals , so 1.135
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gcrank1
Member
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# Posted: 15 Nov 2021 14:59 - Edited by: gcrank1
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Im thinking if you bought 2x 12v/100ish ah 'marine deep cycle' bats ($250ish for the pair?) and wired in series for 24v you would have more power than you are getting out of these 8x 6v that are only 2.5mo old.
Except you may have a 1yr warranty on them? Im thinking they were never fully charged when you put them into service and have been running at deficit ever since. That would be pretty hard cycling.
A lot of places will only throw bats on a 'quick charger' for a short while before 'out the door'. I always charge new bats, one at a time, for at least 24hrs on my home smart charger before putting into service.
Fwiw, it is often said that a person will murder their 1st set of offgrid batteries so dont feel alone.
Id be seriously thinking about returning them to see if I could get replacements under warranty and start over.
Others here may have suggestions to consider.
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bc thunder
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# Posted: 15 Nov 2021 15:09
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Not getting anywhere with bat company atthe moment.
the manager is off today.
Thanks you GC, you have been a steady rock during stormy seas.........
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travellerw
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# Posted: 15 Nov 2021 15:37
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Quoting: bc thunder Thanks you GC, you have been a steady rock during stormy seas
Yup.. %100 agree with GC.. Try and get something out of the company.
Unfortunately, it will be a tough hill to climb as they will blame you. Be persistent without being rude. Even if you get a portion back, thats something..
For starting over.. You may want to look at Costco or Sams. I have built quite a few first systems for people from "GC" (golf cart) batteries from both Costco and Sams. I know of at least one of those systems that is still in use (5 years later). They can also be very affordable. Coscto just had a $100/batt sale up here in Canada. It doesn't hurt so much if you murder an $800 bank!
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bc thunder
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# Posted: 15 Nov 2021 15:52
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I'm up in Canada too, $100 sounds awsome.....
I'm a little gun shy though, to just go grab more off a big box shelf. I think I need someone who knows and services and stands behind what they sell. If this were to happen again, I don't think I could take it.
Also this AIO is turning it"s self on and off on occation, is that battieries or do I have multiple catastrofic hydrolic failure from top to bottom???
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travellerw
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# Posted: 15 Nov 2021 17:30 - Edited by: travellerw
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Quoting: bc thunder I'm up in Canada too, $100 sounds awsome..... I'm a little gun shy though, to just go grab more off a big box shelf. I think I need someone who knows and services and stands behind what they sell. If this were to happen again, I don't think I could take it.
You will find companies that will help you and stand behind their stuff.. but you will pay for that. Nothing wrong with that, but be prepared for it.
With FLA there really is no rocket science. You NEED a good smart charger. You start out by connecting 2 or 4 to make 12V or 24V and charge for at least 24 hours, then move on to the next set (rinse and repeat). After that you hook into the configuration you want and allow 24 hours to equalize. I then like to do another 24 hour charge in that configuration (the smart charger should switch to trickle quickly and you just trickle for 24 hours).
After that I put them in service. Of course you must have a good system you are putting them into. First, I won't build anything without a shunt based battery monitor (like the Victron one I posted earlier). Second the solar chargers need to have good smart profiles that include an equalization phase that can be triggered about once every 2-3 weeks (for full time living, less if its not full time use). Finally you need to ensure backup 120V charger is reliable. If you go to deep into SOC because of clouds, too much draw, ect you will use that charger (usually powered by a Honda) to bring them up.
That is really it for an FLA system. You try to keep you depth of discharge as low as you can and try to get back to %100 everyday (when possible). The equalization phase will not only equalize the cells but help to remove sulphate from the plates. Doing all that will give you a pretty decent life (depending on capacity and depth of discharge every day, life should be about 3-5 years, however I have a set of Costco cells that were removed from service @ 12 years and still have life in them.).
Unfortunately I think the Costco sale has ended and the cells are back at $149 (which is still a good deal).
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gcrank1
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# Posted: 15 Nov 2021 18:55 - Edited by: gcrank1
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Do you have a friend on grid there with an automotive charger, at least a 10amp (20a would be better) with a 6v and 12v setting?
If so, take the 4 bats with the highest SG and have each charged for 12 hrs.
Then hook 2 up in series as a 12v and charge at 12 for 12 hrs.
See and note the voltage of each and each pair as you go.
If they are holding a charge, take home, hook up as your quad 24v bank and give em a go.
You might get lucky
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bc thunder
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# Posted: 15 Nov 2021 19:16
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Unfotunately, I don't know anyone here, as I just moved here. I have no grid power, and my only two friends are smelly, and chase cats. I think the best I could do is hook 4 to The AIO and set the charger for 10a ( I think it goes that low) then run the gen all day.
Hope for the best
I think I need to buy from someone ready to go out the box. Expensive I know, but.....................
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bc thunder
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# Posted: 15 Nov 2021 19:17
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Also we have no Cosco lol
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gcrank1
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# Posted: 15 Nov 2021 19:33 - Edited by: gcrank1
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You do have a local garage/service station or farm implement place dont you? They have chargers and you should make one of them your friend anyway if you are living there. Next on the list of possibilities is a good sized farm or even 4wd motorheads or hotrod people.
Go in, introduce yourself, tell them briefly that your only power is this off-grid set up and you think your batteries are wonky, can/will they charge 4 up in a healthy way and try to save them for you so you can test out for the problem. It might cost you a little bit, ask, or not if it looks like you could become a customer.
That will net you a well charged quad to work with pretty much asap, if they can be saved.
By taking in the 4 with the best SG will give you the best chance and they wont be spinnin their wheels with your worst 4 right off.
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gcrank1
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# Posted: 16 Nov 2021 11:41 - Edited by: gcrank1
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Btw, If it turns out your 6v gc bats are basically junk the thought of buying another set would make me go pale.
Id seriously consider buying 2x 100ah (or more) 12v 'marine deep cycle' bats (NOT marine 'starting' bats) locally. Hook em up in series for 24v. Your usage, sans full time fridge, is not huge. Im pretty sure Ive run your kind of usage loads on my 200ish ah bats with success.
At worst you could use 4, 2s/2p for more ah's but those 4 would be about 1/2 the cost of the 8 gc bats.
The GC bats should have lasted far longer/better but it isnt looking good. The 'marine bats' should last better than your 1st set has and if bought locally you should get better response for any 'issues'.
Fwiw, in multi-bat banks with FLA you should be using matching bats made within a month of each other And made within the past 3-4 months (they are each date coded). Then the dealer should fully charge them for you to pick up the next day and be able to show you on each what volts they are.
Get the paperwork and KEEP it safe!
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bc thunder
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# Posted: 16 Nov 2021 12:47
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I spoke this morning with a locale solar supplier about his batteries. He said he thinks it's becauce my batts are outside in abox, and not inside where it's warm. He said he doesn't think his batts will be any better?
If I get some more here shortly, I will get marine, 4 at most, and the cheapest I can find.
Or I might just ride these out, get what I get, then turn on the gen at night for power and top them off.
Unbelievably, I have two more relitives in hospital, and might need to do a road trip for an extented period.
Life is coming right at me these days, best to get it all now, so the rest of my life will be perfect.
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gcrank1
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# Posted: 16 Nov 2021 14:03 - Edited by: gcrank1
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BC T, 68yr on Ive learned a few things.
I hope yer not hoping for a 'normal life' cause there aint such a thing.....
And, fer sure and certain, 'its always somethin'. Ya might get a pause now and then, but......
Life is An Adventure, roll with it, ROCK sometimes; and when ya get a curve ball Improvise, Adapt and Overcome.
I was just thinking this morning that you are having to deal with far lower temps than I am right now. And when we get as cold as you Im not likely living in my off-grid cabin. Ya, FLA bats take a dive in cold temps. My old rule of thumb is to figure 1/2 of the 'normal' ah's.
Another consideration is that FLA's like to stay charged up, not cycled, even deep cycle bats. To that end I had oriented my array to catch early to mid-day sun and get the prev day's afternoon thru evening discharge replaced ASAP the next morning. If I had to run the gen Id do the same thing, asap in the morning then let my array do absortion thru the day.
Actually, Im usually recharged by noon and thru the day Im running on the excess solar, not the bat-bank, so that bank is all in reserve come time to turn on the lights and make supper.
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