Anyone here knows the difference between the 2 Sanyo models UR18650FM and UR18650ZY? Both have the same capacities 2600mAh and 4.2volts. Is it safe to mix the 2 types (i.e. 2x UR18650ZY and 1x UR18650FM) and use them in my Supbeam K40 and X40? I have tested all 3 batteries and they all have almost the same capacities and IR as tested in my Opus charger. All 3 batteries are new and unused.
Appreciate your inputs.
Thanks.
I would not mix them as they are probably slightly different chemistries (and different batch). You can see some differences in discharge characteristics by comparing datasheets:
http://na.industrial.panasonic.com/sites/default/pidsa/files/ur18650zy.pdf
http://na.industrial.panasonic.com/sites/default/pidsa/files/ur18650f.pdf
UR18650ZY are made in china, UR18650FM will be better.
I don’t know about that. They’re both Sanyos. The cells are made in Korea, and the protection circuits are installed in China.
I’m not sure, but the ZY may be a 4.35v cell.
biggest difference i see is the f is also rated for 2c discharge.
if these are protected run em.
iirc thats a series light.
even with matched cells and careful charging i dont like to run unprotected in series.and i know what i am doing.
Found these.
Bill
Based on the datasheet Chloe linked, the UR18650ZY seems like the better cell. Seems to work better in the cold too.