LifePo4 Charge Performance

BFL13 wrote:
OP you keep changing the story, so hard to advise. If you are happy with the 80AH you get now doing 50-90s, then you can get the same shorter time as with LFPs just by doing 40-80s instead, with what you have now. Constant 45 amps and no tapering by avoiding the 80-90 part. Same 1.8 hours for 80 AH (not 88AH?)

If you need more than the 80AH for camping, you can get say 115 by doing 40-90s now as I previously explained. You could get 135AH in three hours with LFP too, but do you really need an extra 20AH when it costs $1,500 doing it that way? Goodness!

You could just take along an extra 80 AH 12v Rv battery and use its 40AH "useable" to make up the difference, for $100? Or can you get any solar where you are camping?

No info on your rig, camping scenarios, etc as to what your options are.

The way you keep warping the math to make LFPs the answer, I suspect you just want LFPs no matter what. So just do it and get it over with, or it will be like a toothache until you finally see a dentist! :)

Or else we need a good look at the whole situation with rig and camping scenarios to see what your options are that you are working with.

I opened this thread because I've seen plenty of "on-paper" LifePo4 charging scenarios. Wanted to see if they can be confirmed with reports from actual LifePo4 owners. Nothing more, nothing less.

As for me warping the math (or changing the story), in this last post I merely presented an apples to apples (80ah to 80ah) charging scenarios based on my experience with our two GC2's vs. what I *might* expect to get with two 100ah LifePo4's. If my math or assumption about the charging rate is wrong feel free to correct.

Appreciate your suggestions ref increasing ah's with an additional lead cell. We have a truck camper, so space is very limited. Also, our truck camper is pushing the limit in terms of our truck's payload. Any way we can reduce weight is a plus. Two 100ah LifePo4's easily weigh 60 lbs. less than two GC2's. They also offer much more usable ah's between charges and more stable voltage across a vast majority of the discharge spectrum while under heavy load (in our case we need 110a to power our microwave). The low-voltage alarm rears its ugly head way too soon when we load down our GC2's with 110a (only have .15v battery/inverter cable loss at 110a). Every LifePo4 load chart I've seen shows very stable voltage (much higher than 11.0v) from 100% to less than 10% SOC while under heavy load.

In any case, hope this gives you a better feel for our application and why LifePo4's are looking like they *may* be a good fit for us. Outside of cost, and possibly cold-weather performance, we've found very little to not like about LifePo4's.