Lead-Acid (AGM / Gel / Flooded) vs. Nickel-Cadmium (NiCd)
Comparing 2 standards across 9 specifications. 9 key differences identified.
Lead-Acid is the oldest rechargeable battery chemistry (invented 1859), delivering 2.0V per cell (12V nominal in standard 6-cell monoblocs). Despite low gravimetric energy density (30–50 Wh/kg), its unmatched surge current delivery (hundreds of cold cranking amps), low production cost, and 99% recycling rate make it the universal standard for automotive starting/ignition (SLI) and industrial UPS systems.
Nickel-Cadmium (NiCd) is a mature, exceptionally rugged alkaline secondary chemistry operating at 1.2V nominal. Renowned for sustaining massive pulse discharge currents, operating reliably in deep sub-zero temperatures (-40°C), and enduring harsh electrical abuse, NiCd remains in service for aircraft backup power, emergency lighting, and legacy industrial systems.
Specification Comparison Table
9 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nominal Cell Voltage
|
2.00 (12.00 V 6-Cell Pack) V | 1.20 V |
|
Gravimetric Energy Density
|
30 – 50 Wh/kg | 45 – 65 Wh/kg |
|
Volumetric Energy Density
|
60 – 100 Wh/L | 120 – 160 Wh/L |
|
Cycle Life (to 80% Capacity)
|
300 – 1,000 (Deep Cycle AGM) Cycles | 1,000 – 2,000 Cycles |
|
Thermal Runaway Threshold
|
> 200 °C | > 260 °C |
|
Operating Temperature Range
|
-20 to +50 °C | -40 to +60 °C |
|
Self-Discharge Rate
|
3 – 5% / Month | 15 – 20% / Month |
|
Primary Anode Material
|
Porous Sponge Lead (Pb) | Metallic Cadmium (Cd) |
|
Primary Cathode Material
|
Lead Dioxide (PbO2) in Sulfuric Acid Electrolyte (H2SO4) | Nickel Oxyhydroxide (NiOOH) |