SoC chart question from a newbie

[cooose]

Hi, by way of introduction I just made my first cart purchase, a stock 03txt pds. It has a 36v pack...2011 powertron p2000 batteries. When buying I brought along a multimeter and tested each battery and the pack. Being a novice and not fully researching, I was just looking for >6v on each and >36v for the pack, which was the case.

I've since come across a SoC chart from JohnnieB in another thread in this forum. My readings are off the chart so I'm throwing the question out to see what I may be doing wrong.

I charged fully w/ power wise charger and then let the cart sit for approx 10 hrs, here are the readings.

Multimeter set at 20dcv
6.57
6.57
6.56
6.45
6.56
6.43

Multi set at 200 dcv
Pack=39.0

I assume I'm doing something wrong with the multi or I have freakish batteries. Also add, the cart seems to run fine and is pretty quick ~15-18 with just me on flat ground.

Thanks

[Sir Nuke]

not how much difference it will make, but after the charger turns off, you need to let the pack rest for 12 hrs before taking readings. and you do have two batteries that are imballanced. they all should be with .01 of each other. Something tells me that you are, or at least the previous owner, installed some aux. lights or radio and hooked them up directly to two of the batteries on the pack. Not the way to correctly power them, either put a stand alone 12 aux battery in or a voltage converter.

[JohnnieB]

That pesky decimal point. The batteries should be within 0.1V of each other.

I suspect Sir Nuke is right about them being used to power 12V accessories.
Just give them a boost charge with a 12V charger to get the in line with the rest of the pack.

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Most SoC charts are based on voltage values provided by Trojan Battery, and other brands may vary a bit.

Technically, the At-Rest voltage of a "Fully" charged lead-acid battery depends on the sulfuric acid concentration the manufacturer chose to use.
Basically, you can get more AH of storage, with less plate area (less lead) by using a higher acid concentration, but doing so shorten the battery's useable lifespan.

Open circuit terminal voltage is the SG (Specific Gravity) of the electrolyte plus 0.845, so it appears that Powertron uses is one of the brands that uses higher acid concentrations to up the AH storage while using less lead in the plates.

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Also, you DVM might be a little off. If possible, compare it to another DVM.

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Just the pack a couple times back to back with little or no discharge between charge cycle, wait 12 to 18 hours and measure the voltages.
Average the voltage of the top four batteries and subtract 6.37 from it.
Add that number the the voltages on the SoC chart you'll have a custom chart for your battery pack.

[cooose]

Sir Nuke and JohnnieB thank you both for your input.

You're right about the 12v accessory...the lights are coming straight off the pack and there was some sort of secondary device which was removed at some point by the previous owner.