Between low self-discharge NiMH and Li-ion, 13 of the 16 characteristics in the full table below differ; one is the same and 2 can’t be compared because our sources give no figure or rating for one or both.
1.2 V · 84 Wh/kg · 2,100 cycles
An AA or AAA you can recharge up to 2,100 times that still holds 70 % after 10 years in a drawer.
Watch out: 1.2 V instead of 1.5 V: a few devices show a low battery early. Panasonic advises against devices with airtight battery compartments.
3.6 V · 221–260 Wh/kg · 400 cycles
The most energy per kilogram among rechargeables, in standard 18650 and 21700 cells with high-capacity and high-current versions.
Watch out: No charging below 0 °C, and a damaged or shorted cell can catch fire: use protected cells or a BMS.
| Feature | NiMH low self-discharge | Li-ion (NMC/NCA) |
|---|---|---|
| Differences (13) | ||
| Basics | ||
| Nominal voltage | 1.2 V | 3.6 V |
| Voltage range | 0.9 V (empty) to 1.4 V (full) | 2.5 V (empty) to 4.2 V (full) |
| Formats | AA and AAA | 18650 and 21700 cylindrical cells, alone or in packs |
| Example (source of the figures) | Panasonic eneloop AA | LG MJ1, Molicel P42A |
| Energy | ||
| Energy per kilogram | 84 Wh/kg | 221–260 Wh/kg |
| Energy per litre | 273 Wh/L | 597–727 Wh/L |
| Life and storage | ||
| Cycle life | Up to 2,100 (IEC 61951-2:2011); 600 with the 2017 method (Panasonic) | 400 to 80 % (LG MJ1); not stated for the Molicel P42A |
| Self-discharge and storage | 70 % left after 10 years at 20 °C (Panasonic estimate) | At most 10 % in 30 days at 25 °C (LG MJ1 test) |
| Temperature | ||
| Charging temperature | 0–40 °C · fast charge (Panasonic BK-3MCC) | 0–45 °C |
| Discharge temperature | from −20 to 50 °C · rated for use (Panasonic) | from −40 to 60 °C · LG MJ1 from −20 °C |
| Safety, charging and shipping | ||
| Charging | NiMH smart charger (2–3 hours) or 0.1C for 12–14 hours; trickle below C/40 (Energizer) | CC/CV to 4.20 V per cell, never above; packs need a BMS |
| Air transport | Not restricted by air when the terminals are protected against short circuits (IATA special provisions A199 for NiMH, A123 for dry cells) | Lithium-ion dangerous goods (UN3480/3481): loose batteries by cargo aircraft only, at 30 % charge at most; since 2026, batteries over 2.7 Wh packed with equipment must also be at 30 % at most. Passengers carry spares in the cabin, up to 100 Wh freely and 100–160 Wh with airline approval; since 27 March 2026, at most two power banks each, not recharged on board |
| Uses | ||
| Typical uses | Remotes, toys, game controllers, camera flashes, wireless keyboards | Power tools, e-bikes, laptops, flashlights, ESP32 projects on 18650 cells |
| Same on both (1) | ||
| Basics | ||
| Type | Rechargeable | |
| Can’t be compared (2) | ||
| Current | ||
| Maximum continuous discharge | Not stated in our sources | From 10 A (2.9C, LG MJ1) to 45 A (10.7C, Molicel P42A) |
| Safety, charging and shipping | ||
| Fire risk | Not rated here | Higher: NCA cells went into thermal runaway at 207 °C and peaked at 579 °C in 18650 abuse tests; a short or an overcharge can start a fire |
Open the battery comparison →Tick what your project needs and see which of the 15 chemistries fits.
Voltage and charge chart: NiMH low self-discharge →
Voltage and charge chart: Li-ion (NMC/NCA) →
With low self-discharge NiMH: more cycles, long storage, easier air transport, and the AA/AAA format. With Li-ion: more energy per kilogram, more energy per litre, and simple 5 V charging with a one-cell module.
Cycle life for low self-discharge NiMH: up to 2,100 (IEC 61951-2:2011); 600 with the 2017 method (Panasonic). For Li-ion: 400 to 80 % (LG MJ1); not stated for the Molicel P42A. These figures depend on depth of discharge, current and temperature.
No: the voltage of Li-ion is 3.6 V per cell, against 1.2 V for low self-discharge NiMH, and in a device made for AA batteries it can do damage.
LiFePO4 vs Li-ion (NMC/NCA) Li-ion (NMC/NCA) vs LiPo (pouch) NiMH low self-discharge vs alkaline Supercapacitor vs Li-ion (NMC/NCA) LiFePO4 vs lead-acid AGM LTO (lithium titanate) vs LiFePO4 Sodium-ion vs LiFePO4 Lithium AA (Li-FeS₂) vs alkaline
Figures from one or two named cells or batteries per chemistry, from the makers’ datasheets; checked in November 2026.