Nickel-based batteries dwell between lead acid and Li-ion. They are safe, economical and long-living but are increasingly being assigned to niche markets. Table 1 summarizes the characteristics of present, past and future nickel-based batteries.

Chemistry Nickel-cadmium Nickel-metal-hydride Nickel-iron Nickel-zinc Nickel-hydrogen
Abbreviation NiCd NiMH NiFe NiZn NiH
Type Nickel cathode;
cadmium anode
Nickel cathode;
hydrogen-absorbing anode
Oxide-hydroxide cathode; iron anode with potassium hydroxide electrolyte Similar to NiCd; uses alkaline electrolyte and nickel electrode Nickel electrodes, hydrogen electrodes, in pressurized vessel
Nominal voltage 1.20V/cell (1.25) 1.20V 1.65V 1.25V
Charge Taper charger. Constant current; floating voltage Taper charger, similar to NiCd Taper charger, similar to NiCd Not defined
Full charge Observing voltage drop; plateau voltage as override 1.9V Not defined
Trickle charge 0.1C 0.05C Not defined No trickle charge Not defined
Specific Energy 45–80Wh/kg 60–120Wh/kg 50Wh/kg 100Wh/kg 40–75Wh/kg
Charge rate Can be above 1C 0.5–1C Not defined Regular charge Not defined
Discharge rate Can be above 1C 1C Moderate Relative high power Not defined
Cycle life
(full DoD)
1,000 300–500 20 years in UPS 200–300 Very long cycle life (>70,000 partial)
Maintenance Full discharge every 3 months (memory) Full discharge every 6 months Not defined Not defined Maintenance free; low self-discharge
Failure modes Memory reduces capacity, reversible Memory (less affected than NiCd) Overcharge causes dry-out Short cycle life due to dendrite growth Minimal corrosion
Packaging A, AA, C, also in fractional sizes A, AA, AAA, C, prismatic Not defined AA and others Custom made; each cell costs >$1,000
Environment Broad temperature range. Toxic Considered non-toxic Poor performance when cold Good temperature range Operates at
–28°C to 54°C
History 1899, sealed version made commercial in 1947 Research started in 1967, commercial in the 1980s; derived from nickel-hydrogen In 1901,Thomas Edison patented and promoted NiFe in lieu of lead acid; failed to catch on for ICE, EV In 1901, Thomas Edison was awarded the U.S. patent for the NiZn battery Problems with instabilities in 1967 caused a shift from NiMH to NiH
Applications Main battery in aircraft (flooded), wide temperature range Hybrid cars, consumer, UPS German V-1 flying bombs, V-2 rockets; railroad signaling, UPS, mining Renewed interest to commercial market with Improvements Exclusively satellites; too expensive for terrestrial use
Comments Robust, forgiving, high maintenance. Only battery that can be ultrafast charged with little stress More delicate than NiCd; has higher capacity; less maintenance In 1990, Cd was substituted with Fe to save money. High self-discharge and high fabrication costs High power, good temperature range, low cost but high self-discharge and short service life Uses a steel canister to store hydrogen at 8,270kPa (1,200psi)

Table 1: Summary of most common nickel-based batteries. Experimental and less common versions are not listed. All readings are estimated average at time of publication. Detailed information is on BU-203: Nickel-based Batteries.