Big Upgrade and Diet for Our 2019 Off Grid Trailers Expedition Trailer -
After 3 years it was time to replace our factory deep cycle batteries. We had always considered upgrading to Lithium Iron Phosphate (LI) but waited until we needed to make the actual change. The benefits are LI batteries are too long to list. However, the two main benefits are weight savings and the longevity of the batteries. The batteries have a lifespan cycle of 4000 charges! Even after 4000 charges, the battery should still hold an 80% charge.
We went with a Power Queen LiFePO4 100Ah battery (PQ). If you live in a colder climate and would like to charge in colder temperatures self-heating batteries are now available. This battery was purchased directly from Power Queen. Shipping was fast and free!
Isn't she pretty?
Our original Renogy Rover MPPT Solar controller we installed is compatible with LI batteries. All we needed to do was create a custom charging profile. This is well documented in the Power Queen manual.
Process to Upgrade:
Upgrading was pretty easy. Electrical work does not scare us, especially 12-volt systems. We removed the factory-installed NOCO Charger as it was not compatible with LI batteries. Remove the 7-Pin charging wire as charging from the vehicle directly does not provide the proper voltage for a LI battery. The recommended 20Ah LI Charger from Power Queen will be used in its place. We swapped the alligator clips for an XT60 quick disconnect plug. This will allow the charger to be stored elsewhere and only used when required.
This charger can charge a fully discharged battery to 100% in 5 hours. We rarely expect to discharge the battery fully.
The original deep cycle batteries weighed 62lbs each. This new PQ LI battery only weighs 24lbs! We generally don't run our fridge in the trailer so we did not see the need to install 2 batteries. When we feel like it, we can run an SAE extension cord from our 4Runner to the trailer to power the fridge off of this new setup.
Testing placement and the charger.
It's hard to make the wiring look pretty. There are 4 positive and negative wires that need to be connected directly to the battery. Everything else is on the BlueSea fuse block. While a fancier inverter/charger could have been installed we rarely use our inverter. For us, the benefit would have been negligible.
Everything put back together. Quick connect for the charger shown, it will get a cap/cover for when not in use. Yes, our trailer needs a bath!
We can't wait to test this out in the field. A short 3-hour test of running our Truma refrigerator at 40f for 3 hours showed a .1 one discharge on the battery. We did not hook up an amp meter to get a more granular number. A weekend test off-grid is needed. A quick test for solar charging was done with our 100-watt panel. The results were excellent. The battery did not discharge with the fridge running and even charged back up to be put in float mode. Again further testing is needed but we should have no issue keeping this battery charged! We also have a 220-watt EcoFlow panel setup if needed.
Renogy iOS App
The cost of the battery was very competitive with a 100Ah AGM battery. The long-term costs are much less considering most AGM batteries are rated to have a lifecycle of around 300-500 charges depending on the brand/model. The greater ability to discharge a LI battery as compared to an AGM battery also needs to be considered. The weight savings is always helpful and having the better discharge profile of a lithium battery is a huge plus. We are in the early stages of planning an off-grid power setup for our cabin. This micro setup will help us evaluate what we will need. It will likely start with 2 of these batteries installed in series to create a 24-volt system.
We will edit this article with some updated numbers once we have had a chance to run this setup over a few days.