MPPT Charge profile

[Dedou]

I believe the Flooded charging profile for my MPPT controller is better than the lithium profile for my Lifepo4 battery, am I right?

Flooded: Bulk/Abs. 14.4v Float 13.4v
Lithium: Bulk/Abs. 14.6v Float 13.7v

in addition, the dc/dc charger charges during driving 14.0/14.2/14.4/14.6v (which one I want to choose) without float voltage.

 

[MisterSandals]

If your flooded has an equalization cycle that cannot be disabled, that is a no go.

Does your MPPT have a custom battery profile you can add/edit?

 

[mikefitz]

The flooded battery default setting will be temperature compensated, and have an equilization charge cycle. For lithium you dont want either of these charge actions.
A good starting point for charge profiles is to select the defaults used by Victron, 14.2 volts charge and 13.5 volts float.

What modles of charger do you have?

 

[sunshine_eggo]

Most (all?) charge controllers won't use temp comp for lead acid unless they have a temp sensor connected. If no temp sensor, you'll likely not get temp comp.

If GEL, SLA or AGM are an option, those typically do not have equalization cycles.

If I couldn't disable equalization, I still think I would prefer the FLA settings over LFP and rely on the BMS to protect the batteries during an equalization cycle every 30 days vs. running at unnecessarily high voltages.

 

[Dedou]

here are the profiles. Desulphation can be switched off, so the profile is two steps and there is no equalization.

 

[sunshine_eggo]

That's a retarded controller. "desulphation" is "equalization". A controller that imposes 15.8V on Gel or AGM is a great way to destroy batteries. Praise jeebus that it's disabled by default.

Since the desulphation can be disabled, I would choose GEL with desulphation disabled.

 

[Dedou]

I'm most interested in the float voltage, the LFP doesn't need it, so isn't that 13.4 the most optimal in this case?

 

[sunshine_eggo]

I'm most interested in the float voltage, the LFP doesn't need it, so isn't that 13.4 the most optimal in this case?

*sigh*

LFP doesn't need float voltage if you're putting them in storage. If you're using them in a cyclic application, you definitely want it UNLESS, you want to charge to full every day and then watch your battery drain while the sun is shining.

3.375V/cell (13.5V for 4S) is considered optimal to hold them just under 100%.