Switching to LiFePo4 battery

[wrvond]

I've got a Battleborn battery arriving today and will be replacing a lead acid battery in my camper.
I believe there is a dip switch on my MPPT solar controller to select lithium, but is there also a switch on the 120 VAC converter that I need to change?

[DavidEM]

Most RV converter/chargers are pretty dumb. Many have the WFCO 8945 and it doesn't even have a selection to go from flooded cell to AGM batteries, much less lithiums.

You can replace just the charger portion with a Progressive Dynamics PD91xx, the xx being the charging rate you select. With just one BB battery I would keep it down to the PD9145.

David

[Jack Klompus]

Originally Posted by wrvond

I've got a Battleborn battery arriving today and will be replacing a lead acid battery in my camper.
I believe there is a dip switch on my MPPT solar controller to select lithium, but is there also a switch on the 120 VAC converter that I need to change?

It would be better if we knew the details on the charge profile of your converter.

I will say, in very general terms, most modern converters are amazingly well suited to effectively charge LiFePO4 batteries, despite what most folks seem to repeat, especially on RV specific forums.

My (non Li optimized) PD converter is almost perfectly suited to charging my little LiFePO4.

[vsheetz]

Depends on the converter. From your profile you have a 2022 RV, so it may have a lithium capable converter.

Need the brand and model of your converter to look up its features and capabilities.

[wrvond]

Sorry about that.
My distribution panel is a WF-8930/50
My solar charge controller is Victron MPPT 75/15
I've got nothing to tell me what model AC to DC converter I have. It looks like I'll have to remove the distribution panel to see the converter label.
The camper is equipped with the Solar Flex 200.
I purchased this camper in Michigan. The dealer included a lead acid battery in the deal but when I got home I found they had not installed a battery at all. I installed a spare lead acid battery of undetermined age. My brother bought me a Battleborn which arrives today.
I'm sure I read of a three position dip switch that needs to be changed to select between LA, AG or Li but I can't for the life of me find that particular information again. The owner's manual says the converter has a such a switch - if equipped. Not much help there!

[wrvond]

Using the VictronConnect app I found a setting to choose a battery profile. I went ahead and chose Lithium.
A physical examination of the MPPT controller shows no dip switches, so I'm going to assume it knows the difference for now.
At some point I'll likely pull out the power distribution panel so I can see/record exactly which converter I have.

Thanks!

[DavidEM]

The WFCO converter you have does not have a switch to optimize charging for Li batteries. It will charge them but at low rates, maybe 10 amps. Replace it with a PD 9145 as I said above and it should charge your new Li much faster. It also will reach a full charge which your WFCO probably never will.

David

[wrvond]

Originally Posted by DavidEM

The WFCO converter you have does not have a switch to optimize charging for Li batteries. It will charge them but at low rates, maybe 10 amps. Replace it with a PD 9145 as I said above and it should charge your new Li much faster. It also will reach a full charge which your WFCO probably never will.

David

[vsheetz]

The victron smartsolar solar charge controller is fully configurable from the victron connect app.

Rather than using the lithium preset profile, I'd suggest configuring a user profile.

Absorb 14.6v
Float 13.6v
Fixed absorb time 30 minutes.

No equilization.
No temperature compensation.

[vsheetz]

With lithium a battery monitor is highly recommended. A victron battery monitor will use the victron connect app and network wirelessly with the SmartSolar controller to provide voltage sense for more accurate charging.

[Persistent]

As posted above, the WF-8930/50 does not have a Li specific charging profile and there is an upgrade module available.

https://wfcoelectronics.com/wp-conte...l-FINAL-RP.pdf

However Battle Born Li have a pretty good BMS and may work very well with a 100 or 200 amp hour Li battery bank and a WFCO charger.

Check with Battle Born. Give them the make and model of the charger. They have probably tested it already. You may find it listed on the compatibility page of the Battle Born website.

Also have them verify your solar controller. Again provide make and model.

If your Battle Born battery bank is larger than 200 amp hours, see this article on designing your own Li 12 volt system. The bottom line is to have Battle Born vet your whole 12 volt system.

Lithium Battery Systems
https://marinehowto.com/drop-in-life...ated-consumer/

[wrvond]

Thanks guys.

It's just a single 100 amp Battleborn.

[Persistent]

Originally Posted by wrvond

Thanks guys.

It's just a single 100 amp Battleborn.

WFCO charge profile:

Starting with a deeply discharged battery
1) WFCO limits current to max charger can output (bulk charge is 50 amps minus what house is using)
2) Voltage slowly rises to 14.4 volts.
3) Time at 14.4 volts is limited to a maximum of 4 hours from start of bulk charge.
A 50 amp charger on a deeply discharged 100 amp Battle Born will get to nearly full charge in 2 hours. Two more hours are available for equalizing cells.
4) Voltage drops to 13.6 volts
Battle Born BMS equalizes then disconnects from charger. The BMS stays disconnected until battery voltage drops below reconnect voltage. I don’t know what the reconnect voltage is. It may be below 13.6 so the BMS may not reconnect until the battery self discharges and the WFCO goes to the next phase.
5) Voltage drops to 13.2 volts storage maintenance level. This occurs when WFCO current is stable and low for 4 days. Not sure about the time or how low the current must be.
6) WFCO voltage returns from storage level to 13.6 if current changes even a little bit. When the Battle Born BMS self discharges and reconnects, WFCO will jump to 13.6 volts and possibly to 14.4 volts if current draw is high enough.

The bottom line is the WFCO 50 amp without the Li switch is good for a 100 amp hour Battle Born battery. The WFCO may stay too long at 14.4 volts, but the BMS may tolerate that just fine (check with Battle Born). Battle Born maintains a web page showing chargers that Battle Born has tested and found acceptable.

It is marginal for a 200 amp hour Battle Born battery bank. Full cell equalizing from a deep discharge may be too short. Full cell equalizing from 20% SoC may work fine. (Check with Battle Born.)

Not all Li drop in brands are good with that. Some other brands require no more than 2 minutes of equalizing. Always check specification of both charger and battery. Other brands have different requirements.

Larger battery banks lead to other challenges. Fully programmable charging profiles may be needed. Check battery manufacturer’s specs.

I wish you good luck and happy trails ahead!

[Jack Klompus]

Persistent nailed it above.