Advantages, Disadvantages, Comparison of Lithium Battery and NiMH

LITHIUM-ION BATTERIES
- made of carbon and highly reactive lithium
- store a lot of energy
- lithium-ion cells can be charged and discharged faster than NiMH
- no memory effect (happens when battery is re-charged before fully empty)
- not durable in extreme temperatures especially in hot climates
- ultra high power
- superior performance
- environment friendly


ADVANCED LITHIUM BATTERIES
- extended storage life
- longer lasting power
- works in extreme temperatures of -40°C to +60°C
- ideal for use as back-up power in AC powered smoke and CO2 alarms
- 25% lighter than alkaline batteries
- can maintain capacity up to 10 years of storage
- leak resistant construction


LITHIUM POLYMER BATTERIES (Li-Poly, LiPo, LIP)
- use gel-type electrolyte
- gel has energy density (energy/weight or energy/size) that is 20% more than typical Li-ion batteries
- lasts 2 to 3 times longer than rechargeable NiMH batteries
- can hold charge longer
- minimal loss of charge when not in use
- light weight
- can be made in any desired shape 
- typical price $13 each


NICKEL METAL HYDRIDE (NiMH) BATTERIES
- made of nickel, titatium and hydrogen
- use hydrogen to store energy
- less-expensive than lithium-ion battery
- heavier than Li-ion batteries
- can be stored indefinitely either fully charged or fully discharged
- high self discharge rate
- memory effect problems
- overcharging causes deterioration of battery
- pressure build up due to gassing (generation of gas) requires re-sealable vent valve
- NiMH contains no toxic metals
- environmentally safe and friendly (No Cadmium, No Mercury, No Lead)

 
RECHARGEABLE Nickel Metal Hydride (NiMH) batteries
- best and main advantage of NiMH batteries is the cycle life (reuse after charging)
- can be recharged hundreds of times
- battery life is limited to 5 years or less
- life expectancy is 2 to 5 years
- can operate in wide range of temperatures
- higher capacity than nickel-cadmium (NiCd) batteries
- suited for devices needing large amounts of energy and used frequently
- main applications digital cameras, GPS units, MP3 players
- NiMH batteries provide 75% of the capacity of alkaline batteries
- lower drain rates compared to alkaline batteries
- under charging can cause low service life
- overcharging can cause loss of cycle life
- small trickle charges is recommended to reduce bad effects of overcharging
- 2 to 3 hour charging time is ideal for smart chargers 
- fast charging (less than 1 hour) shortens battery life
- battery chargers must protect rechargeable batteries from overcharge
- ideal slow overnight battery charger should apply 0.1 C rate for 12 to 14 hours
- Read more:
http://data.energizer.com/PDFs/nickelmetalhydride_appman.pdf



Comparison of Lead Acid, Alkaline, Nickel Cadmium (NiCd), Nickel-Metal Hydride (NiMH), Lithium Ion (Li-ion), Lithium Ion Polymer (Li-ion polymer):
http://batteryuniversity.com/learn/article/whats_the_best_battery