Hi,
Some initial information:
Advantages and Limitations of NiCd Batteries
Advantages
Fast and simple charge — even after prolonged storage.
High number of charge/discharge cycles — if properly maintained, the NiCd provides over 1000 charge/discharge cycles.
Good load performance — the NiCd allows recharging at low temperatures.
Long shelf life – in any state-of-charge.
Simple storage and transportation — most airfreight companies accept the NiCd without special conditions.
Good low temperature performance.
Forgiving if abused — the NiCd is one of the most rugged rechargeable batteries.
Economically priced — the NiCd is the lowest cost battery in terms of cost per cycle.
Available in a wide range of sizes and performance options — most NiCd cells are cylindrical.
Limitations
Relatively low energy density — compared with newer systems.
Memory effect — the NiCd must periodically be exercised to prevent memory.
Environmentally unfriendly — the NiCd contains toxic metals. Some countries are limiting the use of the NiCd battery.
Has relatively high self-discharge — needs recharging after storage.
Advantages and Limitations of Li-ion Batteries
Advantages
High energy density — potential for yet higher capacities.
Relatively low self-discharge — self-discharge is less than half that of NiCd and NiMH.
Low Maintenance — no periodic discharge is needed; no memory.
Limitations
Requires protection circuit — protection circuit limits voltage and current. Battery is safe if not provoked.
Subject to aging, even if not in use — storing the battery in a cool place and at 40 percent state-of-charge reduces the aging effect.
Moderate discharge current.
Subject to transportation regulations — shipment of larger quantities of Li-ion batteries may be subject to regulatory control. This restriction does not apply to personal carry-on batteries.
Expensive to manufacture — about 40 percent higher in cost than NiCd. Better manufacturing techniques and replacement of rare metals with lower cost alternatives will likely reduce the price.
Not fully mature — changes in metal and chemical combinations affect battery test results, especially with some quick test methods.
The following table is for small batteries.
Source:
About the Author
Isidor Buchmann is the founder and CEO of Cadex Electronics Inc., in Richmond (Vancouver) British Columbia, Canada.