Battery types. pros & cons.

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raverx3m

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theshort description is taken from tis webpage
Cordless power tool batteries: NiCd vs NiMh vs LiIon


Here are the pros and cons of different battery technologies:

NiCd

Pros:
+ charging with very high currents does little or no damage to the battery allowing very fast charging (15 minutes)
+ can provide very high currents, suitable for high-drain application such as power tools
+ work well in cold weather
+ have long shelf life
+ can withstand 400-1000 cycles with minumum capacity loss
+ relatively safe
+ can be stored discharged

Cons:
- has high self-discharge rate (20% or higher per month) 15-20% the first 24 hours, 7-10% the next day
- has low power-to-weight ratio compared to NiMH or LiIon
- very toxic inside and has to be recycled
- can develop internal shorts (dendrites) over time

NiMH

Pros:
+ high energy density compared to NiCD, up to 3600 mAh per cell compared to 2400 in NiCd
+ cheaper than Li-Ion
+ high shelf life
+ can withstand 500 cycles with minumum capacity loss

Cons:
- has high self-discharge rate (30% or higher per month)
- cannot provide as much current as NiCd
- cannot be charged fast without shortening cell life
- freeze at 4 degrees C and must be warmed up to activate catalyst
- must be stored charged
- half the charge/discharge cycles compared to NiCd

Standard Li-Ion

Pros:
+ low self-discharge rate (5% per month)
+ very high energy density (25-33% higher than A123 Systems LiFePO4 Li-Ion aka DeWalt NANO)
+ can be charged fast without damaging the cells
+ can withstand ~1000 cycles with minumum capacity loss

Cons:
- unsafe: can burst into flames and/or explode if shorted or damaged.
- a little expensive compared to NiCd or NiMH
- perform poorly in low temperatures (below 0 C / 32 F)
- toxic and must be recycled
- cannot provide as much current as NiCd
- lower number of cycles compared to A123 Systems LiFePO4 Li-Ion aka DeWalt NANO

A123 Systems LiFePO4 Li-Ion aka DeWalt NANO

Pros:
+ very safe compared to traditional Li-Ion batteries
+ low self-discharge rate (5% per month)
+ high energy density (lower than standard Li-Ion but it's a price of safety and high discharge current)
+ can be charged fast without damaging the cells
+ can withstand up to 2000 cycles with minumum capacity loss
+ perform fairly well in cold weather

Cons:
- very expensive compared to NiCd, NiMH or Li-Ion - up to $16 per cell.
- toxic and must be recycled
- lower energy density compared to traditional Li-Ion.




so in other words:

if you have a LI-ION battery you DO NOT have to fully discharge it, you have to KEEP IT CHARGED all the time.
 
Just about all batteries these days are LiIon

It's been years since i have seen the last NiMh. And I can not even remember the last time I have seen a NiCd.
 
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