01tundra-JAY
Senior Member
Since my other thread was started for the old Trojan battery install I figured I'd start a new one specifically about our LiFePO4 system, especially since there's a lot of questions out there about them now.
This is a small and simple system because that's how we camp, we typically only average around 10Ah of energy usage per 24 hrs when dry camping since we are typically outside most of the time. We really only use a few lights, USB charging, water pump and the little bit of power for the fridge on propane and the LP detector. I've installed switches for the stereo standby mode, refrigerator door heater, etc. so we have total control over everything in the trailer, our resting (parasitic) amp draw is zero with everything turned off, although the only time the LP detector is off is during transit (propane tanks are always turned off while traveling), so with the detector on our parasitic draw is 0.1A per our Victron BMV-712.
I installed two 100Ah batteries in a rear storage cabinet right next to the converter to minimize charge wire length. All power wiring between the batteries and shunt/rear power post are 1/0 Copper. The 12V positive/negative wires serving the converter originate from the factory negative bus and Blue Sea power post located behind the converter. I used 1/0 to connect the factory negative bus to the chassis. The 1/0 is attached to the factory bus bar with large screw-on lugs. I used short (approx. 16") dual 6AWG cables to connect to the fuse block terminals. This was the largest wire that I could cleanly route through the fuse panel area. I backfed the trailer with the factory 8AWG charge wire from the power post with a dedicated 40A Blue Sea breaker. I reused the factory front battery isolation switch as a terminal post on one side for powering the tongue jack, break-away controller and TPMS booster. The former front battery box now serves as a great place to store levelers and wheel chocks.
The factory WFCO 55A converter was replaced with a PD4655L Wildkat converter, which allowed me to reuse the factory breaker/fuse panel. When set in Li mode the converter charges at a constant 14.6V. I typically keep the batteries charged to 90% SOC and disconnected via a Blue Sea 300A master disconnect switch while connected to shore power at home or at campsites with hook-ups. I only turn the batteries on during transit to power the emergency break-away brake controller. If we are going to dry camp I charge the batteries to 100% SOC prior to leaving home, which takes maybe 15 minutes. It's typically recommended to not keep the batteries stored at 100% SOC if they're not going to be used for a while. It's also not recommended to keep a bulk charge on the batteries for more than 2-3 weeks. It's OK to keep a float charge of 13.6V max on them, but this converter doesn't have that mode while in Li mode and it's not really needed. I could run it in normal mode and force it into float mode via the remote pendant, but that's too much trouble with no real benefit for us. WFCO does now make a Li charger that has bulk and float modes and Progressive stated that they have one in the works, but I see no real need for it personally. When initially charging the converter is able to push 56 amps into the batteries and slowly tapers to almost 0 amps once the batteries reach 14.6V.
I also installed a disconnect switch up front that controls whether I allow the truck to charge the batteries or not via the alternator. Since the resting voltage for the batteries is 13.4V at 100% SOC, I don't want the truck drawing the trailer batteries down. We don't do trips with multiple dry camping locations and long drives between and there's zero amp draw on our batteries while in transit, there's no real need for a DC-DC charger.
For solar we have a 200W Renogy Eclipse solar suitcase with the two 100W panels wired in series. We use a Victron MPPT SolarSmart 75/15 controller that's mounted inside the front pass-thru. I mounted the controller up front because we used to have two Trojan T-105's on the tongue. When the batteries were up front I ran a dedicated 1/0 Copper cable between the batteries and converter in the back of the trailer, so when I relocated the new batteries to the rear I repurposed the 1/0 as the connection between the solar controller and batteries. Since we use the factory SAE solar plug on the front side of the trailer everything works out good, I did rewire between the SAE plug and controller with 10AWG wire. This solar system is relatively small for two 100Ah batteries, but since we have no plans to ever run an inverter and want to stay with a suitcase style solar system it all works out for us. Plus recharging 10-15Ah with LiFePO4 is pretty fast with decent sun. I think with our use we can leave our generator at home now when we do 10 day dry camping trips, which is the ultimate goal for Fall/Winter/Early Spring camping.
So this isn't an ideal system for folks who are heavy energy users, but it should be very solid for our use.
This is a small and simple system because that's how we camp, we typically only average around 10Ah of energy usage per 24 hrs when dry camping since we are typically outside most of the time. We really only use a few lights, USB charging, water pump and the little bit of power for the fridge on propane and the LP detector. I've installed switches for the stereo standby mode, refrigerator door heater, etc. so we have total control over everything in the trailer, our resting (parasitic) amp draw is zero with everything turned off, although the only time the LP detector is off is during transit (propane tanks are always turned off while traveling), so with the detector on our parasitic draw is 0.1A per our Victron BMV-712.
I installed two 100Ah batteries in a rear storage cabinet right next to the converter to minimize charge wire length. All power wiring between the batteries and shunt/rear power post are 1/0 Copper. The 12V positive/negative wires serving the converter originate from the factory negative bus and Blue Sea power post located behind the converter. I used 1/0 to connect the factory negative bus to the chassis. The 1/0 is attached to the factory bus bar with large screw-on lugs. I used short (approx. 16") dual 6AWG cables to connect to the fuse block terminals. This was the largest wire that I could cleanly route through the fuse panel area. I backfed the trailer with the factory 8AWG charge wire from the power post with a dedicated 40A Blue Sea breaker. I reused the factory front battery isolation switch as a terminal post on one side for powering the tongue jack, break-away controller and TPMS booster. The former front battery box now serves as a great place to store levelers and wheel chocks.
The factory WFCO 55A converter was replaced with a PD4655L Wildkat converter, which allowed me to reuse the factory breaker/fuse panel. When set in Li mode the converter charges at a constant 14.6V. I typically keep the batteries charged to 90% SOC and disconnected via a Blue Sea 300A master disconnect switch while connected to shore power at home or at campsites with hook-ups. I only turn the batteries on during transit to power the emergency break-away brake controller. If we are going to dry camp I charge the batteries to 100% SOC prior to leaving home, which takes maybe 15 minutes. It's typically recommended to not keep the batteries stored at 100% SOC if they're not going to be used for a while. It's also not recommended to keep a bulk charge on the batteries for more than 2-3 weeks. It's OK to keep a float charge of 13.6V max on them, but this converter doesn't have that mode while in Li mode and it's not really needed. I could run it in normal mode and force it into float mode via the remote pendant, but that's too much trouble with no real benefit for us. WFCO does now make a Li charger that has bulk and float modes and Progressive stated that they have one in the works, but I see no real need for it personally. When initially charging the converter is able to push 56 amps into the batteries and slowly tapers to almost 0 amps once the batteries reach 14.6V.
I also installed a disconnect switch up front that controls whether I allow the truck to charge the batteries or not via the alternator. Since the resting voltage for the batteries is 13.4V at 100% SOC, I don't want the truck drawing the trailer batteries down. We don't do trips with multiple dry camping locations and long drives between and there's zero amp draw on our batteries while in transit, there's no real need for a DC-DC charger.
For solar we have a 200W Renogy Eclipse solar suitcase with the two 100W panels wired in series. We use a Victron MPPT SolarSmart 75/15 controller that's mounted inside the front pass-thru. I mounted the controller up front because we used to have two Trojan T-105's on the tongue. When the batteries were up front I ran a dedicated 1/0 Copper cable between the batteries and converter in the back of the trailer, so when I relocated the new batteries to the rear I repurposed the 1/0 as the connection between the solar controller and batteries. Since we use the factory SAE solar plug on the front side of the trailer everything works out good, I did rewire between the SAE plug and controller with 10AWG wire. This solar system is relatively small for two 100Ah batteries, but since we have no plans to ever run an inverter and want to stay with a suitcase style solar system it all works out for us. Plus recharging 10-15Ah with LiFePO4 is pretty fast with decent sun. I think with our use we can leave our generator at home now when we do 10 day dry camping trips, which is the ultimate goal for Fall/Winter/Early Spring camping.
So this isn't an ideal system for folks who are heavy energy users, but it should be very solid for our use.
Last edited:
.
