LiFePO4 - SOK or Renogy.

pianotuna wrote:
Hi BFL13,

I think folks just want a battery they can "set and forget" and have larger capacity.

The fly in the ointment appears to be that, at least, for LiFePo4 that 40% to 90% gives the best cycle life. I'm very wary of their limitations on temperature, too.

you change that percentage every time you make a post, i have seen you post 10-90, 20-91, 20 -80 and now 40-90. I thought we cleared this up in a different posr, maybe it was thing one.... comercial LFP batteries are built to give you the full rating, yes they put extra capacity and set cut off in the BMS to do it but if you are bouing a 100ah lfp you are getting 100 usable AH and that stays with in your "ideal Range" if you roll your own then you can take advantae of the reall 100% and still get 3000 to 5000 cycles so even if your not staying in the sweet spot on a LFP it still have over twice the cycles on average as a SiO2 being used in the sweet spot or 7 times the life of a normal LA being used from 50-100%

so if you buy a comercial its a drop in and forget for most situations, if its cold the BMS wont allow you to charge it so you dont have to worry about it in your camper that is pugged in all winter. even if you make your own once you get it set up its the same.

now from a cost perspective

for a good 6V GC it is 300 bucks for 245AH and about 800 cycles
so if we look at usable AH over the life vs cost it works out to about $0.003/ah

Sio2 it is 666 each for a GC 260 ah battery so thats rated at 2800 @50% depth of discharge. so that works out to $0.003 /ah

LiFePo4 it is about 800 cdn I'll say 1000 for me to get a 280ah battery right now so the spec sheets say 3800 cycles at 100% dod
so over the life of that battery the cost of an AH delivered will be $0.0009.

the cheepest batery to set up with initial outlay was the normal LA, the second cheepest initial investment was the LiFePo4, and the most expensive was the Sio2.

I think this will surprise a fe people as everyone sees what battle born charges for a battery and such. well the most expensive part about LiFe batteries in the past was the shipping from china, it is droped to 1/4 of what it was 2 years ago and once this virius is tames I expect a further drop. yes I did use an example of making my own battery for the LiFe but if you can wire a battery bank togeather in your rv you can build one. that all it is , you get 4 cells and hook them togeather with bus bars and then add a wire to each one from the BMS.....

Steve