Charging Voltage Windows

Where to set absorption and float, and why the last 5% is not worth chasing.

Absorption, float and the last few percent

Charging to 3.45V per cell gets virtually all the capacity; pushing to 3.65V buys a percent and costs cycles.

Over-voltage is a cycle-life tax and a warranty risk; under-voltage risks a cell going negative under load.

Short answers to the ones that come up most.

What makes LiFePO4 different?

Lower energy density than NMC, but far better thermal stability and cycle life. That trade decides every application it wins.

How long does a LiFePO4 pack last?

4,000–6,000 cycles at 80% depth of discharge — eight to ten years of daily cycling. Heat and sitting at 100% shorten it.

Can it be charged in the cold?

Not below 0°C without a heater. Discharging in the cold is fine, it just delivers less capacity.

Does LiFePO4 need special maintenance?

No watering, no equalising. Keep terminals tight, the enclosure ventilated and watch the BMS log.

Is it safe?

It is the safest lithium chemistry in wide use: no cobalt, stable at temperatures where NMC packs would vent.