Question about battery

[kojo]

I had to buy a battery for my 2010 EZGO and the cart dealer said he
topped off the water and that it checked good. When I got home I put it in
and charged the whole pack like he said. Before I put it in though, I checked
SG with my hydrometer (the kind with the little arrow piece) and it read virtually
nothing. After charging and letting it sit only 3-3.5 hrs. (had to go to bed ,so
saith the wife) the SOC only checks 6.33 and the rest of the pack is anywhere between 6.39-6.45. I'm gonna check SG tomorrow. Battery is a US Battery
just like the rest of the pack. It is about a year older than the rest of pack, I
couldn't find a 2012 like mine. My question is, if the dealer had to put much
water in each cell , would the SG reading drop and have to build back up? Thanks for any advice gentlemen.

[JohnnieB]

Originally Posted by kojo

.............My question is, if the dealer had to put much water in each cell , would the SG reading drop and have to build back up?............

Yes. Of course, how far it builds back up depends on the battery's life history.

Unless some electrolyte was physically removed (Spillage), all the sulfate ions (SO4) originally placed into the battery cells, still are in the cells, however, they exist in two forms. Sulfuric Acid (H2SO4) in the electrolyte and Lead Sulfate (PbSO4) in the plates.

Migration of the sulfate ions from the electrolyte to the plates occurs during discharge and charging causes them to migrate from the plates back onto the electrolyte. As the battery ages, more and more sulfate ions remain in the plates. the plates become progressively more "sulfated" and the storage capacity of the battery becomes less and less.

After two of three charge cycles, the SG of the electrolyte in all the cells in the replacement battery should be nearly the same (+/- 0.050) and very close to the SG of the other batteries in the pack.

US Battery uses a higher concentration of sulfuric acid in their batteries, so you might read SGs of 1.280 or more, but all cells should read about the same.

[kojo]

Thanks alot JohnnieB. I was hoping you would chime in on this question, after
reading several of your replies to random questions it doesn't take a rocket
scientist to figure out that you are THE MAN. Getting back, I have a BLS hooked
up to my batteries, so it may help it even more, hopefully. Anyway, thanks
again JohnnieB. for your reply. You along with everybody else on this forum have
helped a 1st time cart owner out alot.

[JohnnieB]

If the replacement 6V battery At-Rest voltage is running a bit lower than the rest of the pack, lay your hands on a 6V charger and give it some extra TLC.

Getting all the batteries in the pack withing 0.1V will help the BLS do its thing.

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I forgot to ask, does the replacement battery have the same AH rating as the others?

[kojo]

Sorry it took so long, but in answer to your question, yes all the batteries are US Battery 1800 208@20 amps. My original pack are June 2012, and the
replacement battery is May 2011. I'll try to bump it up with a separate charger and see if that helps. Thanks for the advice. HAIL TO THE CHIEF! (had to
say it JohnnieB.)

[JohnnieB]

Some of my antecedents were Cherokee, but they weren't chiefs.

Here is a Voltage vs SoC chart based on US Battery supplied data.
Except for 100% SoC, it is about the same a charts made from Trojan Battery supplied data.

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Something to remember about battery packs is that they are akin to apples in a basket.
Put a good apple in a basket of bad apples and it will soon be bad.
Put a bad apple in a basket of good apples and they will soon all be bad.

Basically, the sooner you can get the replacement battery up to the level of the rest of the batteries in the back, the less negative impact it will have on the others in the pack.

[kojo]

Thanks for the info JohnnieB. I've already jump started the printer and ran a
copy off of the SOC chart you sent so I can have it as a reference. Again,thanks