I hope the same charger will work? I might be a little uneducated in the charger department?
I know FOR A FACT that the Tenergy charger that comes with the blue ones is NOT compatible with the yellow 750 mah batteries, BUT other brand chargers will work with the blue ones. If you buy the yellow 750 mah batteries, you will need the specific charger for those batteries
It says so on every link Ive seen selling them. Here is an example: TENERGY RCR123A LI-ION Battery Charger
I am assuming that the blue 900mah Tenergy batteries use a 3.6v charger just like any standard Li-ion would. Battery junction lists these batteries with an overcharge voltage cut-off protection at 4.3v. This basically would mean they do in theory charge up to 4.2v, but they have an internal regulator that displays them as 3.6v and also built in circuitry that allows them to operate at 3.0v working voltage.
This is why they tell you not to charge 3v lifepo4 (yellow batt) in the 3.6v li-ion (blue batt) charger.
Could be. Anyone have the charger that comes with the blue batts? What voltage does it say it charges to? Should be written on the back somewhere.