Redarc DC to DC 25a Lithium Charging profile question

[chmura]

I have been using the REDARC 25A DC to DC charger for my AGM battery for 4 years now. I am upgrading to 165ah LiFePo battery which need a charging voltage of 14.4 +/- 0.2v.

I have a question on the charge profiles.

I have it set right now to AGM setting which charges at 14.6v

Redarc Lithium setting is 14.2v from the manual.

What setting do I use for this battery? 14.2 Redarc Lithium setting volage is to low for lithium batteries.

Should I leave it in the AGM charge profile?

 

[DiploStrat]

I have been using the REDARC 25A DC to DC charger for my AGM battery for 4 years now. I am upgrading to 165ah LiFePo battery which need a charging voltage of 14.4 +/- 0.2v.

I have a question on the charge profiles.

I have it set right now to AGM setting which charges at 14.6v

Redarc Lithium setting is 14.2v from the manual.

What setting do I use for this battery? 14.2 Redarc Lithium setting volage is to low for lithium batteries.

Should I leave it in the AGM charge profile?

As a rule with lithium iron, better too low than too high. Use the 14.2v.

 

[chmura]

Thanks, was thinking about buying the Victron DC to DC charger as it has more user friendly settings via the bluetooth app.

 

[DiploStrat]

I use both REDARC and Victron. The REDARC lithium settings will be fine. Remember, while lead acid really wants to be sure to get to a high voltage, lithium iron is the opposite. Anything above 13.8v is more than enough.

 

[Peter_n_Margaret]

I charge my 325Ah LiFePO4 directly from the 14.4V alternator if the solar can not keep up.
That is what alternators do.
Charge rate can vary up to 75A (from an 85A alternator), depending on the voltage of the Li. The bigger the voltage gap, the higher the charge rate.
I switch it on via a relay controlled from the cab while driving.
Cheers,
Peter
OKA196 motorhome

 

[DiploStrat]

I charge my 325Ah LiFePO4 directly from the 14.4V alternator if the solar can not keep up.
That is what alternators do.
Charge rate can vary up to 75A (from an 85A alternator), depending on the voltage of the Li. The bigger the voltage gap, the higher the charge rate.
I switch it on via a relay controlled from the cab while driving.
Cheers,
Peter
OKA196 motorhome

The only possible problem that I can see is that a deeply discharged Lithium Iron battery can suck a lot of amps. As long as you don't melt cables or overload the alternator, and is seems like you don't, then this is fine.

The big change is that with lead acid we were always trying to charge to 110%; now, with lithium, you really only need to go to about 80%. Still a culture shock for me.