question

hereandthere avatar image
hereandthere asked

equal temperature of batteries in a string

Hello all, does anybody have some knowledge about the importance of equal battery temperatures?

my setup contains 4 lead-carbon batteries in series, two at the floor and two above that on a shelf.

The two above will be warmed-up by the two below obviously.

The question is how much this is an issue?

thanks in advance!

AGM Battery
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2 Answers
pwfarnell avatar image
pwfarnell answered ·

Lead carbon will be a low resistance AGM battery and more prone to temperature issues. I would definitely recommend that you have temperature measurement on one of the upper batteries as the input to temperature compensation on your charger. I would also have a temperature sensor on the lower batteries. Then make sure your absorption voltage is at the lower end of the manufacturers range and make sure that you have a charger that can go to float when the batteries are full, ideally a shunt on the batteries to control end of absorption by tail current. If you do not charge aggressively then the upper batteries should not be heated by the lower batteries.

3 comments
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Alexandra avatar image Alexandra ♦ commented ·
Agreed. Since they need temperature compensated charging, temperature is important.
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hereandthere avatar image hereandthere Alexandra ♦ commented ·
Thanks a lot Alexandra !

No I'm not overcharging, maxmium recommended for my battery is 40A, but in the VE3 configure somehow I was not able to do more than 35A.

Can I tap into you knowledge of the internal battery monitor of an easysolar?

The SOC which I am currently reading does not make any sense.

Should the internal battery monitor be able to do the job? or is an external one (shunt) highly recommended?

The settings on the internal one are minimal, only efficiency and capacity

thanks

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nickdb avatar image nickdb ♦♦ hereandthere commented ·
You want a proper BMV/shunt. That way you can also measure mid-point voltage and configure it for an accurate SOC.
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hereandthere avatar image
hereandthere answered ·

Thanks nickdb ! I will get one


Best regards

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