Multiplus 12/800 VE Config charge settings for LiFePo4

Hello,

I noticed there are couple similar question but could not find complete answer.

I have a 12V, 190Ah, third-party LiFePo4 that I am looking to charge with a Multiplus but I am lost with setting the charge parameters in VE Config.

Battery specs call for "At room temperature, charged to 3.65V at a constant current of 52.8A, and then charge continuously with constant voltage of 3.65V until the current was not more than 8.8±0.5A";

This means:

Constant Current CC charge at (my case/Multiplus limitation) 30A or max.35A until it hits 14.6V (3.65V per cell); then
Constant Voltage CV charge at 14.6 until charge current drops to 8.8A;

Reading another answer on this forum, I understood the setup I could use is to set the Bulk charge current to 30A followed by Absorption at 14.6V for defined time followed by very low Float (say 12V, 3V per cell) to have zero current.

Question is how can I make Absorption at 14.6V to switch to Float when charge current is 8.8A ? INSTEAD or having a defined time period for Absorption ?

Thank you very much for help

2 |3000

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klim8skeptic ♦ commented · Jan 18, 2020 at 12:06 AM

Hi Paul,

"Followed by very low Float (say 12V, 3V per cell) to have zero current."

This is a really bad idea. Your multi wont charge the battery or supply loads until the battery is at 12v. At 12v your Li battery will be at a very low SOC. Try a more moderate float voltage in the 13.3-13.5v range.

A BMV712 would be a good addition, so you can get an idea of the interaction of battery voltage @ charge current vs SOC.

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