Originally Posted by PhilFromMaine
I agree completely, especially if you are going to use multiple batteries. I changed to a lithium converter and for me, I think it was a mistake.
The vast majority of data out there tells us only to charge lifepo4 to 80-90 percent and to discharge no lower than 20-10 percent SOC. This area of the SOC curve is where lifepo4 is happiest at. Said SOCs are at the "knee and elbow" of the lifepo4 charge curve. Being beyond or below those positions puts added stress on the battery chemistry. These stresses will shorten the total lifespan of the battery. Granted, for some users a shortened lifespan isn't a big deal for an already long lifespan battery. I get it!
Don't disagree that there is a lot of advice like that "out there" however one very important item this overlooks is cell top balance. If you have batteries with properly matched cells, with equal capacity and internal impedance, one MIGHT get away with this for a while but over time even the best matched cells will get out of balance with deep discharging and partial charging.
With more and more inexpensive (and even cheaply made) LiFepo4 batteries on the market I seriously doubt that the effort put forth by the premium battery manufacturers takes place so regular top balancing that, depending on the programming of the BMS, occurs ~the top 10% of the charge cycle but almost always ABOVE 14 Volts.
Over time one will notice a loss of capacity due to one or more cells charging quicker than the others and thus leaving some with even less than 90% SOC if using a converter/charger that doesn't finish charging to 14.2-14.6 volts.
There are workarounds for those using L/A programmed converters. As simple as a Lithium capable maintainer to finish topping off from shore power or solar charging with the controller set to a LiFePo4 charge profile.
BTW, this last week I met with some individuals from Battleborn (at Quartsite RV Show) and they are now verbally indicating expected life from their batteries to be 15 PLUS years. Their charging/storage recommendations remain "Charge to 100% and disconnect. Charge again to 100% at least once per year.
As for me, I keep my TT too busy to only charge within an 80% Soc range. I want to arrive at my boondocking site with full batteries. From there the Solar panels charge to 100% and when skies are heavily overcast, ditto for the generator.
Once again, my Battleborn's will very likely outlast me and still provide my "heirs" many more years of reliable service.