Just for giggles, here's my "boilerplate" LFP summary for RVers, mostly from Maine
Sail, excuse any repetition wrt this thread
Any and all feedback is welcome!
Bare cells: Winston/Voltronix, CALB, GBS, A123 & Sinopoly
Systems: OceanPlanet (Lithionics), Victron, MasterVolt, Redarc (Oz specific?)
Note nearly **every** vendor, also those of ancillary hardware
touted as "LFP ready", gives charging voltages **way too high** for longevity.
My (conspiracy) theory is that manufacturers would prefer their cells get burned out in under 10 years.
EV usage is very different from much gentler House bank cycling. Most EV people talking "lithium-ion" mean other chemistries not as safe as LFP, much shorter lifetimes, and with completely different setpoints and behaviors.
My charge settings for LFP: 3.45Vpc which = 13.8V max for "12V".
Either stop when voltage is hit, or if you want another couple % SoC capacity, stop when tailing amps hits endAmps of .02C, or 2A per 100AH. Note even at the "low" max charge voltage, letting the charge source continue to "push" even low currents long past the endAmps point is **over-charging, and will** greatly reduce lifecycles.
If you can't then "just stop", set Float at 13.1V, but that is a compromise, and *may* shorten life cycles.
With LFP, you don't need to fill up all the way at all, as far as the cells are concerned, in fact it is bad for them to sit there more than a few minutes. Therefore only "fill up" if loads are present, ready to start discharging, ideally right away.
Store the bank as cool as possible and at 10-20% SoC, or maybe higher to compensate for self-discharge, if not getting topped up regularly (I would at least monthly). Letting the batts go "dead flat" = instant **permanent unrecoverable** damage.
Same with charging in below 32°F / 0°C freezing temps.
Persistent high temps also drastically shortens life.
Charging at 1C or even higher is no problem, as long as your wiring
is that robust, vendors may spec lower out of legal
Going above 14V won't add much AH capacity, but will shorten life cycles dramatically.
The point is to look at the SoC vs Voltage chart, and avoid the "shoulders" at both ends, stay in the smooth parts
of the curve. And of course, we're taling about gentle "partial C" House bank discharge rates, size appropriately and be careful feeding heavy loads like a winch
Following these tips, letting the BMS do active balancing is unnecessary and potentially harmful, just look for LVD / OVD and temp protection. Multiple layers of protection are advised if it is a very expensive bank, don't rely on any one device to work
Check cell-level voltage balance say monthly to start, then quarterly, finally every six months if there are no imbalance issues, but only if that seems safe to you.
This thread is long but informative
, make sure to give both Maine Sail and Ocean Planet your close attention.
Also MS' summary notes here
**Everything** at that site is worth reading, very valuable. He also has great articles in Practical Sailor. His new site under development transitioning the pbase content is here
, feel free to make a donation to help with those expenses.
Best of luck and do please report back here.