New Inverter for LiFePo4 Battery?

Hilldweller

Super Active Member
Mar 2, 2021
968
Hog Waller, GA
Here's my Power Converter in the camper
As stated earlier, it'll tread water with a LiFePO4 battery but it'll never swim. It's pretty wimpy.
You'll definitely need to use a dedicated charger at home. You can even use it at campgrounds if you've got power.


When I boondock, my biggest 12v consumer is the little 12v fan that keeps the back of my 3-way fridge cooled when it's running on propane. Sucks more juice than the furnace fan and lights combined. I really need to replace that fan with something more efficient.
 

Hilldweller

Super Active Member
Mar 2, 2021
968
Hog Waller, GA
Yes, but you may want to make a few changes. Electrically no difference. However, Lifepo4 batteries are much more expensive. Make sure you can secure from theft. We moved ours inside the trailer when we did the switch. Cheap battery box on the tongue is now storage for bottle Jack and a leveler block.

Also, you can’t charge a Lifepo4 when it’s below freezing. Being inside the trailer solves that too. Lithium batteries have no gases so no venting required.
Lithium batteries can go into thermal runaway. If you keep it in the trailer make sure you've got it in a robust enclosure.

My battery and the one I linked earlier both have switched self-heating devices built in that allow the battery to charge in freezing conditions. I've used it for several weeks of camping in temperatures well below freezing.
 
May 1, 2022
40
As stated earlier, it'll tread water with a LiFePO4 battery but it'll never swim. It's pretty wimpy.
You'll definitely need to use a dedicated charger at home. You can even use it at campgrounds if you've got power.


When I boondock, my biggest 12v consumer is the little 12v fan that keeps the back of my 3-way fridge cooled when it's running on propane. Sucks more juice than the furnace fan and lights combined. I really need to replace that fan with something more efficient.
Do the shaded or unshaded boxes on my power converter indicate what I have? (8712 or 8725?) In doing some research, it sounds like there are often direct replacements for these stock power converters that will handle LiFePo4 batteries.
 

Taxus812

Active Member
Jun 1, 2010
255
Just went through all this last week.

You can drop it in and run with it as is. There are just some gotchas.

1) If you buy a plugin lithium charger and disconnect the battery when charging that will work fine. Use the battery as you would any other battery. Disconnect it when charging. Least expensive but takes some minor work to setup and tear down

2) If you want to charge it using the converter.
The charge profile of your existing converter WF-8725 will not damage your battery. It will just charge to 70%-90% ish depending on how full the battery was when you started charging it. The negative is after 48hrs the charger kicks into float mode with no loads (13.2V) and some batteries don't like that I believe it would also draw the battery down to 50% if left connected.

3) Upgrade the converter. You have WFCO WF-8725 converter charger they make a lithium version (WF-8725-AD) if you want to upgrade. They are about $250 I got my WF-8955-AD for $215. (https://wfcoelectronics.com/product/wf-8725-25-amp-power-center/)

Side note: First if you have a decent battery, it will have a built-in battery management system. That BMS will stop the battery from overcharging and going into thermal runaway. It will also prevent it from charging if it is too cold or over discharged, stop short circuits etc. A decent battery will have a good BMS. You want that. If you are really versed in electrical, Lithium etc then you can cheap out with a $300 CHINS because you will know what is happening
 

Hilldweller

Super Active Member
Mar 2, 2021
968
Hog Waller, GA
Do the shaded or unshaded boxes on my power converter indicate what I have? (8712 or 8725?) In doing some research, it sounds like there are often direct replacements for these stock power converters that will handle LiFePo4 batteries.
@Taxus812 nailed it.
When shopping for a replacement don't go for one higher in amps than what your stock wiring can handle. I prefer PD over WFCO, btw.

There was a thread on here recently about an auto-detect not working and what had to be done to make it work:
 

Patrick w

Active Member
Aug 13, 2021
586
If it helps, my current plan would be only to charge the battery at home with a dedicated LiFePo4 charger.

I hope I'm not asking the wrong question!

Basically, I'm wondering whether or not I could simply hook a 12v 100ah LiFePo4 battery to my camper in place of the current lead acid battery and have it be able to power my lights and water pump without issue.

I welcome any clarifying questions/ statements that can help hone my question. This isn't about trying to charge the battery with solar or a generator or anything like that.

Thanks for your responses, everyone!

Yes. No usual issues. Its just the question of what wiring needs to go where for possibly brake away switch. Most 12V things tolerate voltages 15V without too many issues. The higher voltage actually reduces current draw and heat.
 
May 1, 2022
40
@Taxus812 nailed it.
When shopping for a replacement don't go for one higher in amps than what your stock wiring can handle. I prefer PD over WFCO, btw.

There was a thread on here recently about an auto-detect not working and what had to be done to make it work:
Is there a reasonable 1 to 1 PD model that would be an equivalent of the WF-8725-AD?

I figure it can't hurt to plan for the future!
 

Taxus812

Active Member
Jun 1, 2010
255
@Taxus812 nailed it.
When shopping for a replacement don't go for one higher in amps than what your stock wiring can handle. I prefer PD over WFCO, btw.

There was a thread on here recently about an auto-detect not working and what had to be done to make it work:

Not to hijack this thread. I looked at the Progressive dynamics version and I like that fact you can adjust the "float" voltage to be the same as the absorption voltage of 13.6 or just set it for 14.4v flat (Renogy like that). I ended up going with the WFCO auto detect so I could swap back and forth. Plus, it was a drop-in replacement with no voltage adjustments required. The cost was close for my version as well.

I do want to mention an unexpected Gitch. The AD had difficulties detecting my battery was Lithium. Once I did a full discharge\charge cycle it kicked into lithium mode and stayed there. I believe the glitch was caused by undersized wire to the battery in my camper. (To the OP that was just an issue with my camper charging at 50A. Standard wire is commonly 8AWG which is fine under 30A. I needed 6AWG wire for 50A)
 

Patrick w

Active Member
Aug 13, 2021
586
Just went through all this last week.

You can drop it in and run with it as is. There are just some gotchas.

1) If you buy a plugin lithium charger and disconnect the battery when charging that will work fine. Use the battery as you would any other battery. Disconnect it when charging. Least expensive but takes some minor work to setup and tear down

2) If you want to charge it using the converter.
The charge profile of your existing converter WF-8725 will not damage your battery. It will just charge to 70%-90% ish depending on how full the battery was when you started charging it. The negative is after 48hrs the charger kicks into float mode with no loads (13.2V) and some batteries don't like that I believe it would also draw the battery down to 50% if left connected.

3) Upgrade the converter. You have WFCO WF-8725 converter charger they make a lithium version (WF-8725-AD) if you want to upgrade. They are about $250 I got my WF-8955-AD for $215. (https://wfcoelectronics.com/product/wf-8725-25-amp-power-center/)

Side note: First if you have a decent battery, it will have a built-in battery management system. That BMS will stop the battery from overcharging and going into thermal runaway. It will also prevent it from charging if it is too cold or over discharged, stop short circuits etc. A decent battery will have a good BMS. You want that. If you are really versed in electrical, Lithium etc then you can cheap out with a $300 CHINS because you will know what is happening
If he can get it up to 85-90% thats perfect. Short of some catastrophic incident, that battery will have a 10 year service life or longer. Battery damage happens at the deep discharge end and the top charging end.
 




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