PowerJack Inverter Charging LiFePO4?

[Jordan94]

Hi all,

I couldn't find another topic specifically relating to what I'm looking for, but recently switched from a lead acid to LiFePO4 battery and was wondering if there's a setting or way to modify the charger circuit so that it doesn't do an equalisation charge?

I tried the settings for voltages 14.4/13.8 which should be fine for the range of my battery but it jumps straight up to over 29.2V and then the battery goes into overvoltage protection.

Thanks,
Jordan

[Sid Genetry Solar]

29 minutes ago, Jordan94 said:

Hi all,

I couldn't find another topic specifically relating to what I'm looking for, but recently switched from a lead acid to LiFePO4 battery and was wondering if there's a setting or way to modify the charger circuit so that it doesn't do an equalisation charge?

I tried the settings for voltages 14.4/13.8 which should be fine for the range of my battery but it jumps straight up to over 29.2V and then the battery goes into overvoltage protection.

Thanks,
Jordan

Unfortunately, there are basically no settings on a PJ...if none of the settings on the charge setpoints knob do what you want, there's pretty much nothing else you can do without getting very technical.

If your inverter has the "DC voltage adjust knob" on it, you might try adjusting that--but you're literally shooting blind, with no readout.  Also worth noting that the "voltage adjust knob" literally adjusts the voltage feedback to the main MCU--meaning that it adjusts EVERY voltage setpoint, including OVP, UVP, and all charge setpoints...simultaneously.

All charge regulation and control functionality is handled in MCU firmware, so there is not really any "circuit" you could tweak to adjust this.  If you're really (really!) handy with small electronics, you might be able to cobble together some sort of op-amp style circuit to "regulate" the voltage feedback to the CPU based on the battery voltage when in charge mode (to force the desired voltage).  But that then begs the question of whether it's worth it.

 

As far as LiFePo4 batteries...I made the switch about 5 years ago, and have never been happier.  They just plug along doing their job day in and day out...no hydrogen gassing to deal with, no maintenance...they just work.

one other note on LiFePo4 batteries: especially if you have a fair sized battery bank (>200Ah), you may find that the weak 0.03A balance currents provided on most BMS units...simply isn't enough to keep the batteries balanced.  The larger the batteries, the higher the intrinsic leakage current is--and it doesn't take much to null out a weak BMS balance current.