question

Robert Bazalgette avatar image
Robert Bazalgette asked

battery balancer with lithium batteries

A new system using 2 x 12v lithium batteries to make a 24 volt supply. Victron Blue smart charge control with 1 Kw of PV. The batteries are nominal 12v , but have a maximum voltage of 12.6v. Operating voltage of 10 - 12.4 v.

When charging, the difference between the batteries is up to 0.6v which is too high. I have set the target voltages in the charge controller 24.4 absorbtion and 24.2 float.

The battery balancers are set to remain off until the voltage is above 26.6. It would be useful to be able to use a balancer in this system, but i see no way to adjust this setting which is too high.

Other solutions ?

Lithium Battery
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von-baron avatar image von-baron commented ·

It would be better if you provide details about the battery, such as make, model and capacity, other people can only make a wild guess.

I do not know of any Lithium battery from any manufacturer that specifies such a low voltage as you have stated for a 12Vdc system, it would hardly seem usable to me.

Also, provide details on the charge controller, which model and I guess, the arrangement of the PV system might be useful to know as well.

The battery balancers, again, what sort are they, we have no idea.

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1 Answer
kevgermany avatar image
kevgermany answered ·

Most lithium is balanced by the BMS.

You should check what the BMS is doing. It might just need time to stabilise if it's a new system. But BMS will not normally start the balancing process until batteries are close to fully charged.

If you can, charge each battery slowly, in isolation until fully charged.

A battery balancer is unlikely to work here.

Like @von baron I find the settings you quote rather strange.

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