Author Topic: Measure battery temp  (Read 13911 times)

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gww

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Measure battery temp
« on: September 01, 2014, 09:03:27 AM »
What are you using to measure battery temp. I have a forklift battery. I unhooked the temp senser from the charge controllers on advice from outback tech support. There was no good way to put it on the battery.

I had been keeping an eye on the battery with the temp senser on a sears clamp meter stuck down in a corner of the batteries but the wire corroded and no longer works. I didn't think that was best anyway, but better then nothing. I have atleast one cell that does not get the sg's up even with hard EQ. What normally happens is I EQ till the sg in that cell starts dropping and then quit.
 I am sure it is going down due to heet.

What is a good peice of equiptment to keep an eye on the battery temp. I spent hours looking on line and didn't really find anything that looked right.
 Thanks
 gww

DamonHD

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Re: Measure battery temp
« Reply #1 on: September 01, 2014, 10:28:04 AM »
With my Morningstar MTTP controller I bolted their matching remote temp sensor onto one of the (gel) battery terminal posts near the middle of the set.  Possibly an anode.

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gww

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Re: Measure battery temp
« Reply #2 on: September 01, 2014, 11:41:10 AM »
damon
Thanks for the reply.  I actually have outback mx 60 and fm80 charge controllers and they didn't play well with the temp senser attatched just on top of the battery cases.  I would like some kind of thermomitor that I can look at.  thought about a glass baking one but the temps on it are wrong (start at 100 degrees) and have to take a battery cap off to use it.  Having a very hard time keeping the sg's up and really want to watch during EQ's.  Thanks
gww

thirteen

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Re: Measure battery temp
« Reply #3 on: September 01, 2014, 01:05:30 PM »
Would a digital house thermoste work by just glueing it on the side of a battery? Or even a remote monitor.  They do need a AA battery to work. I just replaced one in my daughters house so maybe. Just a idea. 13
MntMnROY 13

gww

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Re: Measure battery temp
« Reply #4 on: September 01, 2014, 05:54:33 PM »
thirteen
Thanks, I don't know but the batteries have a metal case around them.  I was hoping someone was using something that they felt was working.  It seems simple and the clamp meter was better then nothing but I don't want to spend 60 plus bucks replacement for just temp.
gww

Mary B

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Re: Measure battery temp
« Reply #5 on: September 01, 2014, 06:19:06 PM »
I put a simple $7 remote thermometer inside my battery box to track air temps(that were within 2 degrees of rthe battery temp reported by my MPPT45).

Flux

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Re: Measure battery temp
« Reply #6 on: September 02, 2014, 03:52:22 AM »
Normally the temperature sensor is to set the charging routine to the battery temperature, which will be close to the ambient near the battery.

You are doing something different and are trying to limit destructive temperature, don't feed this temperature to the controller.Possibly an epoxy coated version of the to220 temperature sensors epoxied to the metal case near the duff cell may work.

I think in the end you are on a looser, by grossly over equalizing the battery to help a poorly cell I suspect you are reducing the life of the good cells.

The better approach would be just to charge enough to keep the good cells in step and deal with the sick cell with a separate high current 2v charger. That would be kinder to the good cells and also restrict the heat to the faulty cell which you are going to have to monitor carefully to try and keep it going for as long as possible.

Flux


gww

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Re: Measure battery temp
« Reply #7 on: September 02, 2014, 08:37:38 AM »
maryalana
two degrees is not much, perhaps I will try that.

Flux
I have a doc wattson hooked to the battery at the 24 volt range.  In charging just the 2 volt cell, would it work simular, ie; just hook charger to the two volt cell and that is all that would be charged even though the batteries are connected with lead bars? 

Are two volt chargers easy to find / make? 

I have only been doing this for a year with a new battery. I went a couple months with a low charging regiment per seller and then called the manufactuer.  Cell 24 has been low since commisioning the battery. 

I have the grid and most times I run off the battery for around ten days then go to the grid for two or three days while allowing the sgs to build.  I EQ once a month and ad water. 

The bad cell gets to 1.272  before droping to 1.270.  The good cells gets to 1.285 to 1.295 and then drop slightly. 

I have 5600 watts of solar.  Most days in the morning the battery is sitting at 48 to 48.8 even if it disconnected due to heavy loads taking it below the low voltage discconect point. 

I don't hit absorb or make quite as much power daily durring summer as I do during winter due to aray angle.  I do get long absorbs atleast every 10 days due to manual munipulation.  I usually only check the sgs on the low cell except durring EQ at which I only compare the low with one high.  It takes about 1and 1/2 gallons water per month.  Any other advice for me?
Thanks
gww

Flux

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Re: Measure battery temp
« Reply #8 on: September 02, 2014, 09:58:48 AM »
Ideally with a new battery they should be equalized and sg adjusted to bring each one within limits. I am not sure whether your low cell has gone bad or whether the sg was never correct from new.

The main thing to watch now is that the bad cell returns to the same sg each time even if lower than the rest. If it gets back to its normal sg at the same time as the main bank then it is probably just wrong sg from new. if it was ok and has now dropped then it will need nursing.

If you have grid you can build a charger with a 6v transformer, a rectifier and a ballast resistor and use it for sorting out rogue cells, it's always a useful thing to have. Off grid a small dc/dc converter would do the same sort of job but could
be more costly initially.

It is not normally advisable to add acid to a battery but if that cell has been low from commissioning I would contact the suppliers and ask their opinion, a little more acid could bring it in step with the rest. This won't fix a bad cell but if it was low from day one it should have been done then and I can't see it hurting now.

I suspect the only way to be sure if it is low acid or faulty would be with a discharge test. If it always takes more charge to get back to normal sg then the single cell charger would be the best way to nurse it.

As long as the small charger is isolated from the main battery it can be run without problem during normal charging, or equalizing or even when the rest of the bank is idle.

Flux

gww

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Re: Measure battery temp
« Reply #9 on: September 02, 2014, 11:12:04 AM »
Flux
My belief is it was low from the get go.  It is hard to be sure due to my first charging regiment was absorb at 57.2  volts and EQ at 62 volts.  My commissioning EQ was about 16 hours and the cell was as it is now.  My fm 80 was holding all charge rates about a volt below these values untill I disconnected the battery temp senser.  I called the manufactuer and my charge values are now 61.4 absorb and 63.4 EQ.  Things are a bit better but who knows if I did damage in the beginning.  I have never gotten higher sg's from cell 24.  I may call the battery manufactuer or just run it this way untill the battery dies.  I don't believe it has gotter worse.  I am new enough to not know but have spent the last year really babysitting the batteries trying to learn.  The old charging rate (first 6 months) during winter never raised the batteries to 90 degrees without 16 hours of EQ.  during summer and the new charge rate I worry more about heat.  I figure everytime my sgs start dropping during charging that I am on the edge of the abbiss. Thank you for your help. 

Flux

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Re: Measure battery temp
« Reply #10 on: September 02, 2014, 11:29:00 AM »
The sg is temperature dependent , it falls with temperature so what I think you are seeing is the maximum sg on full charge with temperature modest, then you are gassing and making heat, the sg then seems to fall as the temperature rises.

If you apply the temperature correction to the hydrometer readings I feel fairly certain it is just staying at the full charge level but dropping due to the temperature rise. You are not in a meltdown situation.

Best not to prolong the equalizing beyond that needed for maximum value, the high temperature and prolonged gassing is only corroding the positive link bars once you are fully charged. Heat is a killer for batteries.

Flux

gww

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Re: Measure battery temp
« Reply #11 on: September 02, 2014, 11:57:03 AM »
Flux
Thank you for your help.
gww

ChrisOlson

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Re: Measure battery temp
« Reply #12 on: September 02, 2014, 07:55:55 PM »
The bad cell gets to 1.272  before droping to 1.270.  The good cells gets to 1.285 to 1.295 and then drop slightly. 

Anything over 1.270 is not a bad cell.  1.275-1.280 for a traction battery is normal at the end of the finish charge (which your Outback controllers don't do), and 1.295 is severely over-charged and should only be taken to that level once every 30 cycles (for most manufacturers) during an equalization charge.

Chances are your cell is fine - it was just filled with a weaker electrolyte solution when the cell was built.  I would contact the manufacturer and ask them if they figure it needs a correction to the electrolyte in it.  And if they don't think it does, then tell them to ship you a new cell and replace it, since with low SG it is obviously going to be short on rated capacity.

Also, with a forklift battery, don't make the mistake of using the 2.40 VPC absorb voltage that is published for a three-stage charger when your RE equipment cannot do three-stage charging.  Virtually all industrial batteries use 2.40 VPC absorb and constant current at 2% C to 2.58 VPC finish voltage.  These chargers are constant-current IUIa profile chargers.

RE chargers don't do this so you have to use a higher (usually 2.50-2.58 VPC) Absorb V, depending on the manufacturer's rec.  Your battery will never reach 100% SOC if you absorb it at the Absorb V published for a three-stage charge profile when you do not have that.

gww

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Re: Measure battery temp
« Reply #13 on: September 02, 2014, 09:03:56 PM »
Hi Chris
I have talked to the manufacture and told him how my charger works and you are correct as my absorb is now 61.2-4 volts.

The new cell would be hard even if I had it as they are connected by lead bars.  Don't get me wrong if it goes bad I won't have a choice.  I am sure you reamember how heavy these suckers are.  Would electrolight mean cell drained or just some added.
Thanks
gww

ChrisOlson

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Re: Measure battery temp
« Reply #14 on: September 02, 2014, 09:39:40 PM »
The manufacturers of forklift batteries usually have service people that come out in a truck to service and/or repair the battery.  They have the stuff to unsolder the lead bars from the jars and replace one under warranty (or at your cost if the battery isn't under warranty).  Replacing bad jars in forklift batteries is done all the time.

If all it needs is to have the specific gravity of the electrolyte corrected, they usually want you to fully charge the cell to insure no lead sulfate remains on the grids and that they are "clean".  Then you pull some electrolyte out and replace with the 1.835 SG acid that battery manufacturers get to build batteries.  If you have a valid warranty claim and suspect that a cell is merely been filled with the incorrect SG electrolyte, they will tell you how much to pull out and replace to correct it.  I would suspect that more than a sulfated cell because the battery is not old enough and has not been abused bad enough to have that problem, and has been equalized charged enough, and it had the problem from new.


gww

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Re: Measure battery temp
« Reply #15 on: September 02, 2014, 11:14:12 PM »
Chris
I don't know if the battery is warrentied or not.  I bought it from calling the number at the giant battery web site.  I didn't question warrenty or recieve papers.  The batteries just went over being a year old. Built by battery builders, which is were the charging help came from.  I didn't check cause I haven't really ever made a warranty claim for anything that couldn't be took back to the store.  It doesn't hurt to ask.  Is the cell hurting the other cells if I did nothing?
Thanks
gww

ChrisOlson

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Re: Measure battery temp
« Reply #16 on: September 03, 2014, 12:20:17 AM »
So it's a GB Industrial.  Those guys are usually pretty good.  I'd give 'em a call and tell 'em what you got going with it.

I doubt the other cells care much.  On a 48V system you can have a cell completely fail, pull it out of the string, and run the system on 23 cells.  It'll work just fine that way until you get a replacement cell.

gww

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Re: Measure battery temp
« Reply #17 on: September 03, 2014, 08:20:28 AM »
Thanks for the help.
gww

phil b

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Re: Measure battery temp
« Reply #18 on: September 08, 2014, 03:05:53 AM »
I asked GNB about charging voltages on my 24 volt batteries. I have three Midnite charge controllers with attached battery temp sensors. I've had no issues with heat, so far. All the cells are within 2 degrees F. I used a Harbor Freight temp sensor for this. Charging them correctly though is another matter. I have an email from GNB below the battery specs.

One thing I took away from several phone conversations with the GNB folks is use them hard and recharge soon. They said their forklift customers will run them "well below" the recommended specs before recharging and they will bounce back. I'd rather take care of them from the start so hopefully they will last.

Absorb is set to 2.43 V per cell for three hours or 5 amps to start float. Float is set to 2.25 V on the charge controllers. After sunset, they ALWAYS go to 2.125 V (25.5) volts without a load. EQ at 30 volts has not changed that. I'm going to try a higher EQ when I do get the batteries to float.

My Battery Specs:
GNB Industrial Power
GJP2206
M2801214017B
Cells 12
volts 24.0
AH C/6 1120
lbs/kg  1,854\841
Type EO
Gravity 1.295

I received the following email from GNB about my 24 volt tubular forklift batteries…
 
"C20 is 125% of C6 so 1400AH
 
There is no bulk/absorb/equalize established for these motive power batteries so  start with the 29.1VDC you're using and monitor recharge.  If it's insufficient bump it up little by little.
Change float to 27VDC

Motive power users equalize these using constant current at a high voltage of 2.8-2.9 Volts Per Cell until they've returned 116% of the capacity…..probably too much too deal with, but that is the feedback I received.
That is the only info available as related to your application"
Phil

gww

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Re: Measure battery temp
« Reply #19 on: September 08, 2014, 05:12:35 AM »
I talked to a guy at the factory "battery builders"  That pretty well ecoed your email.  I am charging the cells absorb 2.55 and equalize at 2.64 and don't remember flote as I never get there very often but believe it is very simular to yours.  It was his hope that these values could be lowered a bit if charging became easyer with use. gb wanted my low voltage at about 44 volts but the factory guy some where around 45.7.  Both wanted some good discharge, expecially while forming the plates.  I don't believe I get this as most of my low voltage disconects are from heavy loads and the battery pops back after disconnecting. 

My sg's however are low enough at times to scare the crap out of me.  Also when I add water It is hard to tell when it is affecting sg's.  you would think adding cool water to a hot battery would cause mixing but I haven't found this to be the case.

I have my absorb set for four hours.  I find after an EQ that two will bring the sg's up the first day or two but on the third or so I just start losing or get no absorb and eventually "10 days" I quit using night time loads and get longer absorbs 4 or 5 hours.  depending on the sun it takes 2-3 days to get the sg's back to start the cycle again.
Thanks for the help
gww

Flux

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Re: Measure battery temp
« Reply #20 on: September 08, 2014, 12:22:16 PM »
Add water before a charge, it will need a good charge with lots of gassing to mix the water with the acid, the best time is before an equalizing charge. Don't add too much water as the level will rise during charging, but traction batteries tend to have plenty of space at the top.

You won't make any sense of sg unless the electrolyte is properly mixed.

In my days with Plante cells there was no electronic charging, they were charged at constant current to a specific voltage and a voltage relay set a timer, the charge continued for a fixed time. I can't remember the voltage or time figures but it wouldn't help anyway for your charging scheme.

The figures quoted look reasonable to me.

Flux

gww

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Re: Measure battery temp
« Reply #21 on: September 08, 2014, 02:22:29 PM »
Flux
I had been adding water to the cells after the EQ.  The reason was three fold. 

One;  even with a good light I couldn't tell how much water they really have in them untill it touches the very bottom of the vent sleave. 

Two;  I can tell that the plates are covered prior to EQ and the water does raise quite a bit during EQ.  afraid of overflow. 

Three;  I always knew the battery was as good as I could get it after an EQ and didn't feel I was taking to big of chance If it took a couple days before the electrolight mixed and I started getting good readings although good reading is a guess at that point of when they actually start.

If these reasons are not good enough I will start adding water before the EQ.  Knowing the water level near the top is the hardest.  The way I do it now still vents a small amount of mist but I have had no real overflows.  My biggest error seems to be when spot checking the electrolight I have several times forgoten to replace the vent cap.

How many times in one day can a guy get up to do something and then forget why he got up?

Please respond one more time if you really think I should fill before charging.  Not questioning just wondering if my reasons make a differance.  more then willing to do it the other way.

Mosly I apretiate that you indicate that my charging numbers are not out in space somewhere.
Thank you for the help
gww

phil b

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Re: Measure battery temp
« Reply #22 on: September 08, 2014, 02:57:21 PM »
My sg's however are low enough at times to scare the crap out of me. 
That's one reason I don't check the SG until the batteries are in float for a while. Another item is getting the hydrometer to read the same consistently. I gave up and purchased a refractometer. That helps.

I only add water when the plates are barely beginning to show. A translucent 16 ounce squeeze bottle works best for me. I only add 8 ounces at a time per cell. More than that means I should have checked it sooner. Any remainder that's needed is added the next morning during bulk just to cover the plates. A small led flashlight is helpful when checking levels. I use the light reflection. The instructions say to fill to 1/2 inch of the fill tube's bottom. If I  do, it will be a mess all over the battery.

ChrisO, I hope you don't mind me quoting you, but this post you made on greenpower talk is just what I needed when I was having problems with SG's and getting the cells voltage consistent. http://www.greenpowertalk.org/showthread.php?t=19149&page=2 
It's post number #36, which is half way down the page, below the graph. I had forgotten all about it.
I used the same scheme, but different numbers. 2.5 VPC was a little high for absorb because it boiled the batteries. That's how I ended up with 2.4 VPC instead. Te set the ending amps, I watched the amps when the batteries went into absorb and watched where the amps leveled off. That became my ending amps. That has gradually changed with time from 20 amps to 10 amps. BTW, my batteries are about 4 months old now.

I have to ask, do you have enough solar or wind to charge your batteries? I have 2 of these big batteries and had to increase solar from 1 kW to 7.1 kw to be able to charge the batteries and run heavy loads like an air conditioner on the same day.  Sometimes I still don't get out of bulk all day. One of my charge controllers has a shunt to measure how many amp hours I'm putting back into the batteries. I also have a Bogart TM 2025 coming just to back up the charge controller.
Phil

ChrisOlson

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Re: Measure battery temp
« Reply #23 on: September 08, 2014, 10:18:27 PM »
I have to ask, do you have enough solar or wind to charge your batteries? I have 2 of these big batteries and had to increase solar from 1 kW to 7.1 kw to be able to charge the batteries and run heavy loads like an air conditioner on the same day.

We had to go to 7.5 kWh of installed solar capacity this summer to get enough power to charge the bank.  Like you, if we're running the A/C the system never makes it to absorb.  But that doesn't bother me too much because we have our system set up to cycle the batteries 50-70 times per year.  In August we had a lot of cloudy days this year and our batteries didn't get fully charged for almost the entire month.  That was a little too long as it took 3 good days to get them back to 1.265 SG and they got pretty warm on the first day charging at high amps in absorb for 6.8 hours.

It should be noted that our system does not use a timer to determine end of absorb.  It uses ending amps.  A battery that's run a long cycle (a week or more) will take more than 5-6 hours in absorb to bring it back to 100%.  Even on days when the battery reaches 100% SOC, then we discharge it to 88% SOC overnight and recharge again the next day, it normally takes over 2 hours in absorb to get it back to true 100% SOC.

gww

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Re: Measure battery temp
« Reply #24 on: September 08, 2014, 11:17:19 PM »
Phil
I just read on arizona wind and sun forum that the best time to check sg's is just after the batterie are charged or at the very beginning of float. 

Myself I do a lot of checking during charging to see if I want to throw more amps at the battery in the time of sun that is left for the day.  Sometime this means turning off the hot water heater that is set to start a few volts prior to absorb/flote.  Some days I drop morning loads.

I have 5600 name plate watts of solar.  I have solar set at winter angle and even though shorter days I do better, if there is sun, in winter.  I don't count the wind as I don't get much.  I still like them but shouldn't.

I EQ once monthly and do water at that time.  Never been in jepardy of being to low on water "yet".  I have writen my daily prodution down since jan but not reasons it might be off at times.  I am retired so I have some time to mulipulate things.

I can't see the bulb hydrometer (bought from naws and too high but don't have to go in public to get) It also is not acurate.  I use an exteck optical hydro meter.  Have to watch the calabration at times.



my battery

I have read and discussed with (on forums) batteries with Chris many times.  To be honest he spent three days explaining hot water opertunity loads with me untill I grasp it enough to try it.  High voltage and ten day full charge are all Ideals he helped  to enlighten (time will tell) me on. 

I would like more solar and wind for these batteries.  Would like a bigger battery.  Like you I stay in bulk most days.  If I didn't have the opertunity load I would probly be fine but it is hard to only make 18 to 20 kwhs daily when it will make 28 to 32 kwhs daily.  If I ruin the most expensive part (the battery) I may feel differantly.

Half the time I think I am ruining the battery by discharge, not charging soon enough, The other half of the time I think I am over charging, 16/20 hour absorb, heat bla bla bla.  It took me a year to just decide 10 days no worry then make sure. 

The only guages that I really use since install are hydrometer, cc's and mate.  I would like to know what leaves the battery and what is put back in but I am a cheep skate.  I have $17000 in everything counting experments but not counting labor.  I know a guy that just grid tied 12000watts name plate solar and after all rebates it cost him in the $6000 plus range and someone else did all the work.  I know I am not smart.
gww

gww

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Re: Measure battery temp
« Reply #25 on: September 08, 2014, 11:33:04 PM »
Chris
I would say I am matching your charging ragime except I pretty much go to the tenth day and then take two or three days to get up then put night loads on and battery low cell hits 1270 within two hours of absorb.  I use the timer for two reasons.  I also don't daily get the full set absorb and I also have watched the charging amps go to 16 or lower and the sgs in no way reflected full charge.  Not even on the high cells.  I just watch the sgs while charging at the end of the ten day period.  My charge controller has a 4 hour max absorb so about one every ten days I will have to force bulk once to get 5 or 6 hours absorb.
gww

ChrisOlson

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Re: Measure battery temp
« Reply #26 on: September 09, 2014, 01:21:58 AM »
Forklift batteries have special charging requirements, and using them in a solar application it must be realized that in the industrial world they get discharged to 80% DoD and take 16 hours or more to fully charge them.  They're designed to run 1,500 cycles @ 80% DOD.  They're not made to baby them, and typically they don't take well to being babied because their tall cells will stratify.  They're much happier if they get the snot worked out of them.

As long as you get the SG's up every 7-10 days or so, you'll be fine with them.  But don't be afraid to use higher than recommended absorb voltages to get the job done in the time that solar power can get it done in.  Some will try to claim that you're going to erode the grids with high voltages, and that's true with light duty batteries like GC-2's.  But them tubular grid forklift batteries are almost impossible to wreck, except by chronic under-charging which will eventually hard sulfate them.  They just are not a "handle it with kid gloves" type thing.

gww

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Re: Measure battery temp
« Reply #27 on: September 09, 2014, 07:32:34 AM »
Quote
They just are not a "handle it with kid gloves" type thing.

Probly the only thing that will save me.
Thanks
gww

phil b

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Re: Measure battery temp
« Reply #28 on: September 09, 2014, 11:43:41 AM »
Forklift batteries have special charging requirements, and using them in a solar application it must be realized that in the industrial world they get discharged to 80% DoD and take 16 hours or more to fully charge them.  They're designed to run 1,500 cycles @ 80% DOD.  They're not made to baby them, and typically they don't take well to being babied because their tall cells will stratify.  They're much happier if they get the snot worked out of them.

As long as you get the SG's up every 7-10 days or so, you'll be fine with them.  But don't be afraid to use higher than recommended absorb voltages to get the job done in the time that solar power can get it done in.  Some will try to claim that you're going to erode the grids with high voltages, and that's true with light duty batteries like GC-2's.  But them tubular grid forklift batteries are almost impossible to wreck, except by chronic under-charging which will eventually hard sulfate them.  They just are not a "handle it with kid gloves" type thing.

Thanks for the advice Chris. I have 24 GC2's on another system. The traction and GC2 batteries are entirely different. If I pushed the GC2's like the traction batteries, they would be bone dry in a week and dead in less than a year.
Phil

ChrisOlson

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Re: Measure battery temp
« Reply #29 on: September 09, 2014, 08:08:56 PM »
Thanks for the advice Chris. I have 24 GC2's on another system. The traction and GC2 batteries are entirely different. If I pushed the GC2's like the traction batteries, they would be bone dry in a week and dead in less than a year.

Yes, the GC-2's and so-called "marine deep cycle" 12V batteries that are so common are some of the most fragile batteries there are for solar power storage.  They typically lose 20% or more of their rated capacity within 150 cycles and are usually good for 400-500 cycles and they're dead.  The grids are very thin and just don't stand up that well to the type of charging seen on solar power systems.

Industrial traction batteries are on the other end of the scale.  We have some local folks here that have a 24V one (that I helped install back in the day) for over 20 years, and although it is down on capacity from new, it is still meeting their needs in their off-grid home.

Frank S

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Re: Measure battery temp
« Reply #30 on: September 09, 2014, 09:58:04 PM »
Chris O; Do the "L16"s fit somewhere in the middle?
I live so far outside of the box, when I die they will stretch my carcass over the coffin

ChrisOlson

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Re: Measure battery temp
« Reply #31 on: September 09, 2014, 10:28:36 PM »
Chris O; Do the "L16"s fit somewhere in the middle?

Usually they do.  The L-16 comes from the floor maintenance industry.  They're a light duty industrial battery.  They're definitely more hardy than golf cart batteries.

kitestrings

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Re: Measure battery temp
« Reply #32 on: September 09, 2014, 11:04:13 PM »
I have no experience with these type of batteries, but I would assume you might want to consider some sort of venting?  It looks to be a fairly enclosed space.

~ks