When I bought my TD the AGM battery in it was toast. I decided to use a 12v 40ah LifePO4 that I had as the replacement. I'm a CPAP user and my CPAP machine is rated at 6.67a so over a period of 7 hours it would use ~47a. That's more then my 40ah LIfePO4 could put out. The 12v circuit would only be used for running my CPAP plus possibly running a phone charger if needed. I could really run the phone charger off the TV while traveling to save battery usage..
I had planned to get a 100ah LifePO4 down the road but feel that it's needed now. A LifePO4 battery has different requirements when it comes to recharging. My TD came with a 4 pin wiring harness which I had changed over to a 7 pin plug so that I could recharge while traveling. With the LifePO4, the charging wires will need to pass thru a 12v 20a DC-DC charger to prevent over-taxing the TV alternator. The 100ah LifePO4 would run approx $200 plus another $170 for the DC-DC charger and another $20 for a shunt so that comes to approx $390. The 100ah LifePO4 could manage to put out approx 95ah until requiring a recharge..
Going with the 200ah AGM deep cycle battery allows me about 50% usage that would be equal to the 100ah LifePO4 for power output. With the AGM, I wouldn't be required to use a DC-DC charger as I could wire it up directly to the incoming wire from the 7 pin plug. I think that I'd prefer to still use the shunt for monitoring the battery usage. A 200ah AGM would cost approx $350 plus another $20 for the shunt coming to $370 total..
Overall the costs for either system would be about the same. I think the 100ah LIfePO4 would be much lighter to handle and much safer to use plus I could wire in the 40ah LifePO4 I have now into the circuit to increase system output to 140ah right off..
Looking at both systems, I feel the LifePO4 setup to be the better route to take. What's everyone's opinion on which is the better route..?
Helmuth