What it it?
- 10A discharge, self-protection circuit inside.
- 3 Ahr
- 18 minutes of 37W
- 10W for 1 hour
- 100 of these give 1 kWhr
- 45g each, so 1 kWhr weighs 4.5 kg.
- At this density, ultra light cars (500 lb total) - will have 30 miles per kwhr.
- 1kwhr ~ 4MJ - so about 1/10 kg gasoline. Given gas is 20% efficient in cars, we have 1/2 kg equivalent. Tbis gets us to about 240 mpg equivalent.
- With 1 kW solar added- that gets us to about 400 mpg equivalent.
- Can 18650 cells really discharge at 10A rate? Yes!  - Panasonic goes up to 20 amp rate. 6S (6 cell) packs are 22v. 10 of 6s cells, if discharged at 20A, give a 200A welder for 6 minutes. See Discharge Rate.
- Crappy ones can be as low as delivering 2.5A each - . With 100 of these, that's still a 250A welder which has a weight of 5 kg for the batteries. Still impressive.
- Discharge rate of 20A yields temp increase to 50C - 
- Note actual spec from a buyer on Amazon - 
- While specs say 250 cycles for 15A discharge - Multiple thousands of cycles are possible when charged to 80% and drained to 30%. - 
- From <$1 to $7 each - so choose wisely -
- Cheapest - 
- Best - Samsung 30Q - 3000 mAh - $3 in bulk - 
- These appear to be on spec at 3000 mAh - .
- Cycle life and specs -  - 250 cycles to 70% of rated
- 1000 cycles at 6A discharge rate bottoming at about 60% capacity for 2000 cycles? - . So these last pretty long.