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JasonTav avatar image

Lithium Battery Smart - Initial Cell Balancing

Hi,

I am attempting to do an initial charge and cell balance on 2x LFP-Smart 12,8/150 batteries.

They will be configured in series when deployed.


As per the manual (section 3.2), I have connected them in parallel and am charging at less than C/20 (which is 7.5A...)

The batteries are connected to a ve.BMS and the chargers are connected via a battery protect that is wired to the "charge disconnect" output on the BMS. Each battery is protected by a fuse.

The charger options I have are:

Smart Solar 150/35 (charge limited to 5A)

Blue Smart IP67 12/17 (set to Li-ion and 6A)


Absorption voltage is set to 14.2


The problem I have is that the chargers aren't staying in the absorption phase very long, and switching to float, and therefore the cells aren't balancing properly (50mV difference between some cells on both batteries)


MPPT firmware 1.41 has static absorbtion time, but is there an yway of configuring that currently without the SmartSolar Control panel?


was hoping at least one of these chargers would enable me to initially charge the batteries, so any help much appreciated.....

MPPT - Solar Charge ControllerLithium battery Smart
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3 Answers
Charlie Johnson avatar image

We use a power supply with variable output voltage.

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thanks, and you set to 14.2V with a small current limit?

Yes if you can limit to about 0,5A per battery when the battery reaches this voltage, it works best.
Having the 'smart' version, you can check the cell voltages inside when doing this.

Daniël Boekel (Victron Energy Staff) avatar image

You can temporarily set the float voltage at 14,2 volt to do this.

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PatrikOls avatar image

Installing LFP-12.8/200 smart batteries right now. I have Blue Smart IP65 12/10 and as I understand it's not a perfect solution because I can't set the float to 14.2V or is it a way to do this?

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