01:33 03-01-2026

Charging LFP EV batteries: when 100% helps and when it doesn't

Many EV drivers follow a simple routine: keep the battery around 80–90% and only push to 100% before a long trip. With LFP (lithium iron phosphate) packs, the logic can be different. You can see it in the cars’ own prompts: for some Mustang Mach‑E versions, Ford advises charging to 100% at least once a month, and for LFP-equipped Teslas, the company for a long time recommended leaving the limit at 100% and reaching a full charge at least once a week.

The point isn’t that LFP chemistry inherently prefers a high state of charge; it’s about the battery management system (BMS). The BMS estimates condition and range from voltage, current, and temperature. Because LFP’s voltage curve is generally flatter in the middle, skipping periodic 100% charges makes accurate calibration harder. A full charge helps the BMS reset its boundaries and improves how reliably the car reports what’s left and how far it can go.

LFP is usually cheaper to produce, regarded as more thermally stable, and often lasts longer, but it comes with trade-offs: lower energy density—so, all else equal, less range—and poorer performance in severe cold. That’s why LFP commonly appears in more accessible trims such as standard Tesla Model 3/Model Y and base versions of other models, bringing electric cars closer to the mainstream.

Even so, treating 100% as a rule for every case isn’t the answer. There’s evidence that frequent full charges can accelerate unwanted processes inside the cells, although in real use there are plenty of LFP cars that show only minor capacity loss even with regular 100% charges. The sensible approach is to follow your car and its manual: if the manufacturer asks for 100% once a week or once a month, do exactly that instead of following someone else’s rules.