- A Type of Electrically Rechargable Battery
- Has one of the highest power desities
- Can have a Battery Fire issue, also lithium availability may become an issue in the future (although recycling is possible)
- Most common form (pre-battery pack unit) OTS is the 18650 Battery (similar in form factor to a "AA" type battery, different specs though)
Depth of Discharge
Discharging only a little bit and recharging prolongs life - 10 years if 10% discharge, 6 years if 25% discharge
- $56 for 100 of 20Wh batteries - 3.7V, 5.8Ahr. 2000Whr for $56? 
This is a good review. Standard is 2200 Ah for 16850 cells, 3.7 v - 8 Wh of power. 
- Ultrafire at 1 Ah and 4A is worth the $1.2. Cheaper than all others, for half capacity.
- Further - if it's 1 Ah and 72 cents - it appears to be 370W for $67, or under $200 per kW? Definitely would be worth it.
- Protected vs unprotected - 
Not High Drain
- 2600 advertised -