The short answer
LiFePO4 (LFP) units generally state longer cycle life and are heavier per watt-hour; NMC lithium-ion units are typically lighter. Cycle-life figures are the makers' claims under their own test conditions — compare them with care.
The trade-offs
| LiFePO4 (LFP) | NMC lithium-ion | |
|---|---|---|
| Stated cycle life | Often listed in the thousands of cycles to 80% capacity | Often listed in the hundreds to low thousands |
| Weight per Wh | Heavier | Lighter |
| Typical use case | Standby, home backup, frequent cycling | Portability-first units |
| Price | Varies widely; price per kWh is in our tables | Varies widely |
Compare actual products in our LiFePO4 power station table, which shows each model's stated chemistry and cycle life.
Reading a cycle-life claim
- Check the end-of-life capacity (for example, "to 80%"): 3,000 cycles to 80% is not 3,000 cycles to 50%.
- Check the test conditions (depth of discharge, temperature, charge rate): makers use their own.
- For standby backup, calendar life, storage temperature and how you keep it charged matter as much as cycle count.
Wattstanding calculationA battery used for 20 outage cycles a year takes decades to reach 3,000 cycles; real life is limited by calendar ageing and storage conditions, not just the cycle figure.
Safety
LiFePO4 is widely regarded as more thermally stable than some other lithium chemistries, but neither is risk-free. Use the maker's cables and chargers, keep units out of heat, and follow the manual. Wattstanding does not make safety claims about any specific product.
Figures marked as Wattstanding calculations show their working; product figures come from the sources on each product page. How we work