Spark offers 18650 batteries. They are assembled in Germany with Sanyo cells of Japan. They are not cheap, but the price included registered shipping all over Europe.
The price in the first week is 13€, after this 16,90€. It's much better as AW price in Germany (you pay around 22€ + shipping) for one 2600mAh AW.
- Nominal voltage: 3.7V
- Protect circuit: 5A
- Capacity: 2600mAh
- Cut-off voltage protection: 3.0V
- Charging voltage protection: 4.2V
Cut-Off 3V. I do not like that. This cells hardly can hit 2600mAh at a termination voltage of 2.75V. Sanyo even calls them 2500/2600. So I expect max 2450 mah from these.
The price is $17.5 for a pair or one cell?
Now the price is 14,70 EUR for one cell
Yep, pricing is for individual cells, not a pair.
Sanyo 2600mAh from CNQG can hit 2471mAh as just tested (terminated at 2.826V on DMM as measured, 1A discharge). Tried the best to optimise contact already....
The good thing about them is that at 1A, the sag is very minimal at 3.95V as displayed be IMAX B1 (forgot to measure with DMM). The same XTAR 2600 fresh cell (supposed to be Sanyo as well?) drops to 3.54V on the display at 1A.
Not sure about the Spark. But that is why the Sanyo 2600 unprotected gives me the best current for direct drive lights (even better than the Panasonics). Mitro also says that it has the best "knee", not surprising at all.
I got my Sanyo 2600s for 5 bucks only (shipped), but only purchased 3 because they are unprotected.
I would have to presume that the protection circuit added to the bare cell increases the overall resistance of the cell, and that no doubt explains the higher degree of sag in comparison to the bare, unprotected cell.