question

grsh avatar image
grsh asked

battery voltage in series

Hi

I installed 2 12v 330ah Smart Lithium Batteries with a ve.bus bms v2.

Connected the batteries in series to run my 24v system. Everything works fine but the batteries have different voltages and status in the app

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img-9652.png

Is everything ok ?


Thanks Markus

smart lithium
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4 Answers
seb71 avatar image
seb71 answered ·

Before connecting cells or batteries in series, you must make sure they are all at the same charging level.

Since an intermediate charging level is extremely difficult to be determined accurately, best option is to have them fully charged before connecting them in series.

If you have an MPPT, you can use it to charge each 12V battery separately.

If possible, partially discharge them (let's say to about 3.10-3.15V cell voltage/ 12.4-12.6V battery voltage) before fully charging each separately.

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derrick thomas avatar image
derrick thomas answered ·

You need a balancer.

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grsh avatar image
grsh answered ·

Ok thanks

Will charge them with my MPPT. That’s a great idea

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seb71 avatar image seb71 commented ·
Make sure it is set properly for 12V LIFePO4.
1 Like 1 ·
grsh avatar image
grsh answered ·

Thanks @Seb71

  • Charged the batteries with a 12v 10A charger an now the voltage is perfect

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