LiFePO4 Upgrade for a 2016 Itasca Navion

[Bnystrom]

You can easily fit a single SFK 300-340Ah battery in the battery box, and they even have a video showing how to fit a pair of them there. Their quality is outstanding and their pricing is better than Epoch.

 

[johnpeace]

Here's what I've learned based on my own upgrade project.

• I haven't heard anything negative about Lion Energy batteries, other than that they're expensive. Perhaps Costco's price makes them competitive.
  • I don't know how they can have "a 100% American supply chain" given that they're using cells made in China, like everyone else. More than likely, their BMS and case are made there, too. There's nothing wrong with that, it's just the reality of the current market. US engineering and assembly should result in high-quality products.
• There is no need to add an external BMS to a battery that has an internal BMS. I think you're confusing this with a "shunt", which is used to monitor the current flowing in and out of a battery.
  • If the batteries you're considering have a Bluetooth monitoring app that's reasonably comprehensive, you really don't need a shunt, but it may be more accurate. I find the app for my SFK batteries to be more than good enough.
  • I agree with the others who suggested installing a single 200-300Ah battery. SOK makes a really nice 206Ah battery at a reasonable price. SFK has an excellent 315Ah battery, built here in the USA.
  • The battery box will accommodate a pair of 200Ah batteries and it's even possible to squeeze in a pair of 300Ah SFK batteries. There's a video on their website that shows this. It all depends on how much power you want to have available. I'll warn you, it can be addictive!
• There are two issues related to the alternator when you switch to LiFePO batteries.
  • The alternator output voltage - typically ~14.1v - is too low to fully charge the battery. However, it will charge it to over 90%.
  • The current draw of the battery may be high enough to cause the alternator to overheat, but it depends on the battery capacity and the maximum charging current it can accept.
  • Both of these issues can be fixed by installing a DC-DC charger. That said, a DC-Dc charger is not typically necessary for LiFePO installations of 200Ah or less. Above that, I wouldn't take the chance of going without one.
• Installing a DC-DC charger requires some new wiring, but it's not particularly complex (see the diagram).
  • Essentially, it bypasses the boost solenoid, which is disabled by removing the trigger lead, so you don't have both systems trying to charge the batteries.
  • This disables the "Battery Boost" function, but it can be re-enabled by simply installing a switch in the trigger lead. If you need to use the Battery Boost, turn on the switch. Otherwise, leave it off. The wiring for this is very simple.
  • The D+ trigger lead for the charger can be connected to the "Elec Step Ignition" breaker in the passenger's seat pedestal.
• There's no need to upgrade your inverter unless you plan on powering high-draw devices, which you indicated is not the case.
  • With only 200Ah and a small inverter, you won't be able to run the A/C, but with a bigger inverter and higher battery capacity, you can. This is nice to have, but adds considerable cost and complexity.
• If your new converter is lithium-compatible, great. If not, check with the manufacturer to see if they offer an add-on compatibility module for it. Worst case, it will only be capable of charging your batteries to ~85%.
• Yes, your battery disconnect will continue to work. I'm not familiar with Trik-L-Start wiring, so I can't comment on that.

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This is really helpful. I am in the middle of LifePo battery install right now. My mechanic and I are doing it, it's not clear to us where the DC-DC charger goes...I have a 30a Victron (https://www.amazon.com/dp/B07ZKG396Y?ref=ppx_yo2ov_dt_b_fed_asin_title), it is pretty big. Did you mount this under the passenger seat?

 

[Bnystrom]

I actually installed a 60A Renogy DC-DC charger under the passenger's seat. It's considerably longer and wider than an Orion, but not as tall. I won't say it was easy, but it fit. I'm not endorsing this product, as I've had issues with it and with the company. If it fails again, I'll replace it with a 50A Orion.

Many people have installed the Orion units here, either mounted vertically on the front panel, or horizontally in the middle somewhere. If you mount it horizontally, you should install a fan as well, as the cooling system is designed for vertical mounting. You'll also want to cut some air vents in the foam cover for the seat base. Check YouTube for installation videos.