Originally Posted by
smasha
numbers from wikipedia...
AA - Alkaline batteries - 1.5V from
1700 - 3000 mAh (up to 4.5Wh)
AAA - Alkaline batteries - 1.5V from
250 – 1200 mAh (up to 1.8Wh)
18650 - li-ion - 3.7V from
2200–3400 mAh (up to 12.58Wh)
in other words, an 18650 can hold a lot more energy (and produce more light, for longer) than AA or AAA batteries.
Thats a bit like saying since a quart is smaller than a gallon - a gallon is better. AAs and AAAs are physically smaller than 18650 batteries - of course they hold less energy! It takes more of them to do the same job, but it still breaks down to total watt hours, and I have no problem running 10W LEDs off AA cells. More batteries to charge, and heavier than lithium, but no other issues.