question

Mardhin avatar image

Smart Lithium Battery in Series not Balancing

we have 4 Smart Lithiums batteries 12.8V in Two Strings parallel in Series for an 25,6 V Systems. We have charged all Batteries to 14.2v and then put them togehter. After 30 days the Batteries at the negative Side get charged between 14.27 to 14.35 and the Batteries on the positive Side get charged only between 13.98 to 14.07.

After 8h of balancing the difference is getting better but only a little bit. We tested all Connections and Charched the Batteries again seperatly.

But the Problem is still there. Now our Victron Dealer told us to install an Balancer!!!

Lithium battery Smart
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1 Answer
Daniël Boekel (Victron Energy Staff) avatar image

Hi @Mardhin

What are the cell voltages when fully charged?

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They are in an range 3.49to 3.54 in the low charged batterys and 3.54 to 3.61 in the high charged batterys. The difference between the cells in one battery can be up to 100mv and after balancing more times and over 2 h still 30-50 mv.

Hi @Mardhin

That's good! if all cells are above 3.45V when fully charged (no more amps flowing in), all cells are fully charged.

for perfect balancing, leave them fully charged for longer.

Mardhin avatar image Mardhin Daniël Boekel (Victron Energy Staff) ♦♦ ·

hy daniel to do nothing or balancing hours and hours is no solution!

thx to mvader for the support and the update for the lithium battery balancer to fix such problems. now they are in balance and we hopr this works well.

Bathnm avatar image Bathnm Mardhin ·

Hi Mardhin, I am about to install an identical system, 4 Smart Lithium 12,8, in two serial strings, and then two parallel. How did you get them balanced in the end. I am currently putting them through a full charge to balance the individual batteries as per section 3.2 of the manual. Did you end up installing a battery balancer between the serial units.