School me on LiFePO4 batteries conversion in RV

GmFamBam

GmFamBam

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My RV is due for new batteries; it currently runs 2 6v batteries. Want to upgrade them with LiFePO4, RV doesnt have Solar, we usually run the genny in the mornings for coffeee then again in the evenings while making dinner.

Can i just replace them with 2 100ah LiFePO4 batteries?

Will my stock converter/charger be able to charge them?

Or Can I just connect a NOCO or similar charger to them, and everytime the genny runs it will charge them?

Any advice is much appreciated
 
Justdirt said:
Would need to change the converter to LI compatible pretty cheap now a days
Click to expand...
Yep, and depending upon which one you have you may just need to change a jumper setting on the board. I replaced my converter circuit board last season and the new one has a jumper that can be swapped in position to support lithiums.

Without changing the board out, the lithium compatible nocco is a ghetto option but you would want to full disconnect your converter from the equation so it's not beating up the LiPos at an insufficient voltage
 
I swapped to 2 100Ah LiFePO4 batteries about a year ago. These new batteries have a very low internal resistance and when the charge level is very low will tax your alternator charging system. I installed a Victron 30A DC-DC (much cheaper than Amazon on Marketplace) and it limits the charge current to 30A, and it also works with my older MH battery charger. The DC-DC will take a lower input voltage and increase it, and utilize a 4 stage charging scenario.
You get almost 2x the battery power vs lead acid or AGM because you can't discharge a lead acid battery past 50-60%, but a LiFePO4 will let you use almost 100% of its power, and maintain a steady voltage the whole time. Another benefit is the Victron has bluetooth and lets you see how the batteries are charging. I use one of these to keep track of the battery level, works awesome.

Check out DIY Solar Power with Will Prowse on Youtube for cheap but good battery recommendations. They have gone up a lot in the last year, I got 2 Wattcycle 100A batteries for close to $100 each last year.
 
Justdirt said:
Would need to change the converter to LI compatible pretty cheap now a days
Click to expand...
HozayKwarvo said:
Yep, and depending upon which one you have you may just need to change a jumper setting on the board. I replaced my converter circuit board last season and the new one has a jumper that can be swapped in position to support lithiums.

Without changing the board out, the lithium compatible nocco is a ghetto option but you would want to full disconnect your converter from the equation so it's not beating up the LiPos at an insufficient voltage
Click to expand...
Id love to swap out my convertr to a LI compatible....I dont think my converter has that option on the circuit board, a jumper setting. RV is an 04 Pacearrow, Ill have to find out what converter it has, next time im at storage ill check it out. Thanks
 
Turbo_Manx_Maniac said:
I swapped to 2 100Ah LiFePO4 batteries about a year ago. These new batteries have a very low internal resistance and when the charge level is very low will tax your alternator charging system. I installed a Victron 30A DC-DC (much cheaper than Amazon on Marketplace) and it limits the charge current to 30A, and it also works with my older MH battery charger. The DC-DC will take a lower input voltage and increase it, and utilize a 4 stage charging scenario.
You get almost 2x the battery power vs lead acid or AGM because you can't discharge a lead acid battery past 50-60%, but a LiFePO4 will let you use almost 100% of its power, and maintain a steady voltage the whole time. Another benefit is the Victron has bluetooth and lets you see how the batteries are charging. I use one of these to keep track of the battery level, works awesome.

Check out DIY Solar Power with Will Prowse on Youtube for cheap but good battery recommendations. They have gone up a lot in the last year, I got 2 Wattcycle 100A batteries for close to $100 each last year.
Click to expand...
This sounds doable. How did you install the Victron 30A DC-DC?
 
GmFamBam said:
Id love to swap out my convertr to a LI compatible....I dont think my converter has that option on the circuit board, a jumper setting. RV is an 04 Pacearrow, Ill have to find out what converter it has, next time im at storage ill check it out. Thanks
Click to expand...
Def not on an '04 but guarantee whatever Progressive Dynamics converter/charger is in there they'll have a drop in replacement that is LiPo compatibale without replacing the entire sub-panel
 
It's pretty simple to hook up the DC-DC, it just goes inline between the Alt/batt charger wires and the coach batteries. It will take whatever voltage comes in and upconvert it to 14.6V to charge the LiFePo4 batteries.
I had 2 Trojan 6V batteries, and with 2 CPAPS and the heat running all night long they would go down to 50-60%. With the new LiFePO4's, they don't go below 80% with the same load. I can dry camp for 3 days without running the generator. I do have a Honda 2K and it will charge the batteries pretty fast if I let them get too low.

BTW, the Victron stuff is industrial and super reliable, stay away from the cheaper Amazon ones, I tried Renogy first and was super frustrated, it had issues shutting down after the engine was stopped, and their support was shit. I was Director of Engineering before I recently retired, so I understand this stuff pretty well. Let me know if you have questions.
 
HozayKwarvo said:
Def not on an '04 but guarantee whatever Progressive Dynamics converter/charger is in there they'll have a drop in replacement that is LiPo compatibale without replacing the entire sub-panel
Click to expand...
I've done the swap and wouldn't go back. I replaced the 2 6v with one 230ah battery from litime. It fits in the stairs right were the 2 6v went.A few things I learned.
1. I removed the fuse in my Bounders bcc that essentially disconnects the solenoid to allow the battery to be charged by the alternator. Everything else still works like normal even the backup switch that connects the house and chassis batteries together if you need a little extra boost if the chassis battery drains a bit sitting.
2. I went with a rec pro ac to dc charger to replace the progressive dynamics one. I tried the p.d. one with the auto lipo setting but it would never switch to the 14.6v that u need to get to 100%. The rec pro has a manual dial once it is set it is good to go.
3. A friend has the same setup as me but he kept the stock ac to dc charger and installed a separate lipo charger he can plug in to a generator. So if his rv is plugged in it will essentially keep the batteries at 80%.
4. If you want to know what percentage the battery has you need to install a shunt. I did a renogy cause I have renogy solar. But my first shunt I had to send back cause it would glitch out and not work sometimes. The 2nd one is working much better so far. I did buy it after covid and maybe the quality of work wasn't as good then. Not sure.
 
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