# Battery trouble



## TheSGC (Nov 15, 2007)

What do you have for a charger? And what kind of AMPs are you drawing from them? 

I too have noticed a massive decrease in range and performance in the cold. On the order of 2-3x less range and performance has dropped like a stone. What temps are we talking about? From my research/data these batteries only about 50% capacity at 32F.

My batteries are on their 10th charge cycle, and I bought them summer 08. I am individually charging them with 6 AMP smart chargers, the Schumacher SC-600A on each battery and I am using 8 Walmart MAXX29 12 volt 125 Ah in a 96 volt system. I have just started my range testing and data collecting, so I don't have any definite range info.


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## rmay635703 (Oct 23, 2008)

Sorry to say it but...

Sounds like a case of driving the same in cold weather, batteries are easier to push over the edge when its cold, they have less capacity and you usually have more friction on the road to boot, both from your thick oil in the differential and from the snow and ice covered roads.

Once you push a battery too far (or even 1 cell in a battery), its easier and easier to push it too far, what you describe sounds like a bad cell or bad battery(s)

My fathers Miles ZX40 had the same issue during this cold snap, normally it is easy to make it into town and back with plenty to spare but at 5 below it wouldn't make it even with an opportunity charge, I checked and I have a bad cell in each battery now  Pretty pathetic

Thats how it sometimes goes

If you want to check batteries to see if there is a bad cell follow the instructions in the video
http://www.chinadepot.com/batripod.html there, all you need are some old coat hangers and a multimeter.


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## ElectriCar (Jun 15, 2008)

Cold weather kills my batteries. This AM is was 20F. On a full charge the voltage dropped to 120V from 155 or so. On warm days when full it only drops to maybe 140. I have a 144V system.

One thing I learned just yesterday and could be part of most of your problem. The acid will precipitate out of solution and settle on the bottom in flooded LA batteries. This will lessen the ability of the battery to recharge properly and obviously lower your range and power. 

I have a Zivan NG5 charger and yesterday I noticed my PakTrakr freaking out saying my batteries were being overcharged. The pack voltage was reading about 190 and individual batteries were reading 8.1 or 8.2V! I'd never seen it over about 178 or so. 

I called Bob at EV-America and questioned him. He told me what I saw was the charger in the final stage of charging, which is called the equalization charge. He says the batteries will be bubbling like crazy and you'll smell the fumes but the purpose of this is to bubble the acid back into solution, increasing the range and power!

If you don't have a charger that does this I don't know how you'd do it otherwise. Here's a link about battery maintenance that explains equalizing charge.


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## evcars (Mar 15, 2008)

Thanks for the good info. The charger I use is from Kelly which I bought with the controller. It's a 96 volt 12 amp and I believe it has a three stage charge process. By now I have about 1500 miles on these batteries but recently the temp has been a lot colder than when I was use to driving the car more often during last summer/fall. I hope its just the temperature affecting the range. I just wasn't sure why the electrolyte looked cloudy when I was checking the specific gravity. I hear the batteries bubble and sizzle even if they are not being charged. Is that something they do normally?


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## Coley (Jul 26, 2007)

The brown color indeed seems to be a bad omen.

I had the same thing happen to me with the Farm & Fleet 12 volt marine batteries I had. Once they turned the brown color, they were never the same.
After I took one apart, I found the brown was from most of the lead sulfate
floating in the water.

A lot had come off the plates and was laying in the bottom of the battery. No amount of vigorous charging would bring it back or clear the water.

I used smart chargers and all, on them, to try to save them.

The winter weather isn't causing the brown color, as I got it in the summer also. They just couldn't take the cycles of charging/discharging well.
My average discharge was only 20%, as I only go 5 to 10 miles a run.

Good luck with Sams on the warranty......


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## rmay635703 (Oct 23, 2008)

If he wants to know which batteries have issues all he needs is a old metal coathanger, some sandpaper and a multimeter.

Dip the coathanger "lead" into the first cell and touch it and the assocated terminal with the multimeter to find out how that cell is doing, it only takes one bad cell to really mess up your ride.

Cheers
Ryan



Coley said:


> The brown color indeed seems to be a bad omen.
> 
> I had the same thing happen to me with the Farm & Fleet 12 volt marine batteries I had. Once they turned the brown color, they were never the same.
> After I took one apart, I found the brown was from most of the lead sulfate
> ...


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## evcars (Mar 15, 2008)

rmay635703 said:


> If he wants to know which batteries have issues all he needs is a old metal coathanger, some sandpaper and a multimeter.
> 
> Dip the coathanger "lead" into the first cell and touch it and the assocated terminal with the multimeter to find out how that cell is doing, it only takes one bad cell to really mess up your ride.
> 
> ...


 
Here is a diagram of my battery pack and the individual cell readings. I'm not sure why the first cell of every battery was lower than the rest. Also, almost every time I would go back and check a cell, the reading would be different +/- 0.1 volts. How do these numbers look? 

BTW, the electrolyte doesn't look cloudy anymore.


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## madderscience (Jun 28, 2008)

I am coming up on 4000 miles on my battery pack (trojan T-105s) and the individual batteries (3 cells each) still come to rest after charging within a few hundredths of a volt of each other. I haven't tried the coathanger trick to see what the individual cells are doing though. I've only really pushed the range once or twice though.

Brown / cloudy electrolyte is a bad sign. period. Sulfuric acid is (should be, anyway) a clear solution. If and when you refilled electrolyte, did you use distilled water? Introducing contaminants (such as tap water from iron plumbing) is a good way to mess up batteries.

It seems a little odd to me the the first cell of each battery would be low unless there is a design problem with the sam's batteries that causes that particular cell to fail early.

Have you tried specific gravity measurements on each cell? That is probably the most deterministic way to tell if one cell is way off from the others. If the cells that have low voltage also have a lower specific gravity and it won't recover with an equalization charge then those cells (and by extension, batteries) are probably beyond help.

I know it costs more, but go for trojan or interstate batteries for your next batch. Add a couple more if you can, or change from 8V to 6V and add more to get to the same voltage. If you can find a way to insulate the batteries, do it. Even just adding some plastic sheet or something to keep wind and spray off of them if they are exposed will help.

Good Luck.


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## Jimdear2 (Oct 12, 2008)

xtreme cartz said:


> Here is a diagram of my battery pack and the individual cell readings. I'm not sure why the first cell of every battery was lower than the rest. Also, almost every time I would go back and check a cell, the reading would be different +/- 0.1 volts. How do these numbers look?
> 
> BTW, the electrolyte doesn't look cloudy anymore.


 A loooooong time ago in arrcarft mechanics school I was taught that to perform this battery cell voltage test you started by reading the voltage between the POS term and the first cell, then you checked between the first cell and the second cell and on till you run our of cells then you check between the last cell and the NEG term. That will give you readings like 1.70 - 2.2 - 2.2 - 2.2 - 0.5. You will notice that the first and last readings (the ones from the terminals and the cell) add up to 2.2 volts. The reason for coat hanger (or any other disposible conductor) is obvious.

A looooooong time ago the reason for this was explained, but I don't remember. They say memory is the first thing to go . . . Who are you and what were we talking about.

It appears that the last step was omitted in xtreme cartz procedure. This test is a bit more accurate and indicitive of cell condition then a hydrometer and can be performed in areas where ha hydrometer wont fit. 

I have some free AGM batteries I'm trying to recycle (so far I have 18 out of 50 hawkers holding a charge and a good load). When the weather warms a bit I'll try doing this test on them, using various methods of contacting the wet glass mat and see if I can get any acurate data. 

I'll post the procedure and results when/if I get them.

Someone with GELs could try this and post also. 

Jim


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## evcars (Mar 15, 2008)

Oops Jim's right, I left out the last step in measuring the cells. I do remember a low number like .30 in the last cell to neg terminal but didn't think to add it to the first cell. 

Thanks for all the advice.


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## evcars (Mar 15, 2008)

Alright here's the corrected numbers with the first and last cell added together. How much should they be off by? All of the cells are within 0.1 volts of each other except for the battery with the 2.52 and 2.08 cells.


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## Jimdear2 (Oct 12, 2008)

extreme cartz,

One thing I have not seen mentioned here is that heating and cooling and cold causes shrinkage and loosening. Please Check ALL of the connections for loosness. Be sure it is not a lot of additional resistance killing your performance. 

For myself I would cycle (discharge and charge) the one battery that is off voltage and retest it. I would also contact the battery manufacturer for two important bits of information.

1.) Their cell voltage to state of charge charts, so you *know* what is good or bad.
2.) Their temperature to performance graph. This will tell you if what is happening is normal. If thie graph tells you that a 40º drop in temperature will cause a 50 % drop in capacity, you can stop looking for problems and start looking for ways to fix it.

With a lot of batteries the fall off in performance with a temperature drop is drastic.

For DIY tests you can try to store the vehicle in a warm location (a local gas station?) overnight or however long it takes to bring the batteries to 70ºF and then try your drive again to see how they hold up.

Be sure you are charging your batteries just before you leave not the night before. Charging tends to heat the batteries.

For myself I would just look for a way to insulate and warm the batteries. There are as many ways as there are people thinking about it. 

It really sounds like you are right on the edge on capacity for your driveing needs though, and any small percentage drop is going to kind of pull you over the edge.

Good luck
Jim


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## Coley (Jul 26, 2007)

Quote:
"Be sure you are charging your batteries just before you leave not the night before. Charging tends to heat the batteries."

I would suggest that you charge your batteries as soon as you get home or at the end of a run. This is best for battery life. Driving a little slower the first mile or so will heat them, about as much as a charging.

Then, before you leave, give them a charge for an hour, or so as you get ready to leave.

A timer setup is very easy to use for this.

I have been doing this for a couple years and it works good for me.


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## rmay635703 (Oct 23, 2008)

Sorry I didn't describe the battery test procedure completely...

You may wish to use an old 2amp dumb battery charger and do a slow charge on the battery with the overcharged cell and the one thats low. After 8hrs-24hrs hopefully all cells will equalize or at the least the one baddy will come up.

My experience is that when one cell that is low next to one that is quite high usually indicates that battery is probably causing trouble, after you drive test the voltage of that battery compared to the ones next to it, it probably won't be real good as the one cell probably drops low.

If you have a battery desulphator like a battery minder, let it do its magic on that battery for a week and go through your lower voltage batteries letting each run about a week with the battery minder. Or if you have a higher voltage unit group the bad batteries together and desulphate them all at the same time. You can also build a pulse battery charger to keep your batteries running best, I have linked to its schematic many times.

The pulse desulphators usually work very slowly and you leave them working whenever the batteries are on a charge.

Good Luck


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