17670 Li-on

[HumanLumen]

Can anybody shed any light (!) onto why the 17670 are way behind 18650s in capacity as thier cubic capacity is not much less - if the 18650s are aprox 1600mAh, the 17670 should be ~2200 - the best I can find is the 1800mAh Ultrafire - unless you know different......

HL

 

[45/70]

Possibly, it has to do with the fact that the cubic measurement doesn't take into consideration that the casing, protection circuit, nipple etc. are the same dimensions as for an 18650, except for the diameter.

Also, I wouldn't put too much faith in xxxxxFire capacities printed on the cells.:)

Dave

 

[rmteo]

Supply and demand. 18650 cells were designed to replace 4/3A NiMH such as these http://www.batteryspace.com/nimhrechargeablecellsanyo43af12v4500mah1pc.aspx
which are used in large (think massive compared to flashlights) quantities in laptop computers. As such they have seen continuous development in capacity, charge/discharge rates, cycle life, etc., compared to other sizes such 17670, 14500 and some of the smaller ones.

 

[Kestrel]

Another reason, my 17500's measure only ~16.9mm in diameter, while my 18500's and 18650's are ~18.4 mm in diameter - the actual measurements need to be the ones used in the calculations.