Major upgrade and diet for our 2019 Off Grid Trailers Expedition Trailer -
, by Yue Wu, 4 min reading time
After 3 years it was time to replace our factory deep cycle batteries. We had always toyed with the idea of switching to lithium iron phosphate (LI). But we waited until we actually had to make the change. The benefits of LI batteries are too long to list. However, the two most important advantages are the weight savings and the longevity of the batteries. The batteries have a life cycle of 4000 charges! Even after 4000 charges, the battery should still be 80% charged.
We chose a Power Queen LiFePO4 100Ah battery (PQ). If you live in a colder climate and want to charge in colder temperatures, self-heating batteries now exist. This battery was purchased directly from Power Queen. Shipping was fast and free!
Power Queen 12.8V 100Ah LiFePO4 battery, Built-in 100A BMS
Isn't she pretty?
Our original Renogy Rover MPPT solar controller that 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.
Upgrade process:
The upgrade was pretty easy. Electrical work doesn't scare us, especially with 12-volt systems. We removed the factory installed NOCO charger as it was not compatible with LI batteries. The 7-pin charging cable was removed because charging directly from the vehicle does not provide the correct voltage for an LI battery. The recommended 20Ah LI charger from Power Queen is used in its place. We swapped out the alligator clips for an XT60 quick disconnect connector. This means the charger can be stored in a different location and only used when needed.
Power Queen 14.6V 20A LiFePO4 battery charger
This charger can charge a fully discharged battery to 100% in 5 hours. We rarely expect the battery to be completely discharged.
The original deep cycle batteries weighed 62 pounds each. This new PQ LI battery weighs only 24 pounds! Since we don't generally run our fridge in the caravan, we didn't see the need to install 2 batteries. If we feel like it, we can run an SAE extension cable from our 4Runner to the trailer to run the fridge through this new setup.
Testing the position and charger
It's hard to make the wiring look nice. 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 better inverter/charger could have been installed, we rarely use our inverter. For us the benefit would have been negligible.
Everything put back together. Quick connector shown for the charger, there will be a cap/cover for when not in use. Yes, our trailer needs a bath!
We can't wait to try it out in practice. A quick 3-hour test in which we ran our Truma refrigerator at 40 degrees for 3 hours showed a 0.1 percent battery discharge. We didn't connect an ammeter to get a more accurate number. An off-grid test is required at the weekend. We did a quick solar charging test with our 100 watt panel. The results were excellent. The battery didn't discharge when the fridge was running and even recharged to go into trickle mode. Again, more testing is needed, but we should have no problem keeping this battery charged! We also have a 220 watt EcoFlow panel setup if required.
Renogy iOS App
Conclusion
The cost of the battery was very competitive with a 100Ah AGM battery. The long term cost is much lower considering that most AGM batteries have a lifespan of around 300-500 charges depending on the brand/model. The greater ability to discharge an LI battery compared to an AGM battery also needs to be considered. The weight savings is always helpful, and the better discharge profile of a lithium battery is a big plus. We are in the early stages of planning an off-grid power supply for our cabin. This micro setup will help us assess what we will need. We will probably start with 2 of these batteries connected 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 facility for a few days.
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, by Liu Ling Wie lange halten Wohnmobilbatterien?
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, by Liu Ling Wenn eine Lithiumbatterie feucht wird, was passiert dann? Wie kann man vorbeugende Maßnahmen treffen?
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, by Yue Wu Wie man LiFePO4-Batterien auflädt？
