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markbuilt asked

Recommended settings for BMV712 Smart for LFP / Lithium?

What are recommended BMV 712 settings for my 2x 200Ah LiFePo batteries? I’m not clear on Charged Voltage, Tail Current, etc. Thank you!

BMV Battery Monitorinstallation
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boekel answered ·

Charged voltage: this is the voltage that has to be reached to sync to 100% charged (along with tail current and a time setting)

Charged voltage: absorption voltage (or a little below)

Tail current: the recommended current the battery manufacturere advices to stop charging, a bit above that. As this is a percentage, you'll have to calculate from the battery capacity (you say 2x 200Ah, if they're in parallel (12v) it's 400AH, tail current of 4A = 1%

The best settings might require some experimenting, depending on the system (you didn't mention how they will be used). especially systems with solar can sync too early in low-sun conditions.

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ahtrimble avatar image ahtrimble commented ·
I am trying really hard to understand "best" settings for my LifePO4 battery bank. I have 3 batteries, 630Ah (48v). I want to run my batteries 17% - 90% SOC to length their life cycle.

I am looking at setting my bulk charge voltage to 56v and absorption to 54v for 2 hrs and 0 tail current.

I can't figure out 2 things:

1) What should be my "float" setting?

2) What the heck exactly is "tail current"? I think I want it set to 0 to allow cell balancing. But I don't actually understand what tail current is.

I live in very sunny AZ so I want my MPPTs to keep running even after my batteries hit my target of 90%SOC so the MPPts can power my AC, etc. in the afternoon. But I am at a loss to really understand how I can accomplish my goals of not over/under charging my batteries while maintaining my MPPTs production and not drawing my batteries down when full sun is present.

Any thoughts, ideas, suggestions?

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