LFP Charge Efficiency

[sailorboy1]

I am 1.5 weeks into havng my 400aH LFP house bank. I have reason to believe I may have my battery monitor charge efficiency set too low. With solar I am charging at around 0.03C and with alternator or battery charger at around 0.15C. So pretty slow rate really.

What are other using as charge efficiency?

[wholybee]

Charge efficiency should be 99%
Peukert 1.05
If either of those are left as they were for AGM your battery SOC will read a bit lower than it really is, and might not ever read 100% even if fully charged.

[sailorboy1]

thanks, I never have had agms. But have my BM set to 97% and today based on voltage and charge acceptance I felt the batteries were 99% soc while the BM said 92%.

[sailorboy1]

turns out I had the charge efficiency at 98% already so that does seem much difference

So I changed the program for the dumb "smart" battery charger. Maybe it is some super secret thing in its' settings.

[Scubaseas]

FWIW when I put my 400AH LiFePo4 bank in the battery monitors (one internal on the battery BMS and one Balmar SG200) both took a while, like several cycles until the SOC started to make sense. Rarely does the SG200 and the bluetooth SOC on the battery BMS agree. Usually within 5% SOC though.

[lmxr]

Charge efficiency 100 % and Peukert 1.00. When we re-synchronize after one month of daily cycling, the synchronization delta is only around 1 %, so it works pretty well for us.

[sailorboy1]

Well been weeks now.

Yesterday running the generator and battery charger the batteries got to 0 ah out and 20 minutes later the batteries were still accepting all I could supply them. I had been feeling that voltage in morning was lower than they were a month ago, even though my battery monitor was saying the SOC was the same.

So I think I need to lower the charge efficiency.

[Fuss]

Originally Posted by sailorboy1

Well been weeks now.

Yesterday running the generator and battery charger the batteries got to 0 ah out and 20 minutes later the batteries were still accepting all I could supply them. I had been feeling that voltage in morning was lower than they were a month ago, even though my battery monitor was saying the SOC was the same.
.

Yea… I used to have a sh** battery charger like that once too.

[sailorboy1]

thanks for the informative and useful post