Comment by Tade0
6 hours ago
Word of warning: batteries from AliExpress might not be the size it says on the tin.
Also: not all lights require soldering to change the battery. Some brands, like Fenix, offer lights where you can change the battery on the go.
I had a light from a lesser known Taiwanese brand - an INFINI Lava 500. At some point it stopped working, so I took it apart with my iFixit kit and inside was a 102660 battery (1700mAh instead of the advertised 2600mAh), so I bought a 102560 unit - 10mm thick, 25mm wide and 60mm long (supposedly).
It was a good few millimetres longer and didn't fit. What's worse - AliExpress stopped shipping batteries to my address, because due to safety regulations you can't ship batteries via airmail, it's just that one vendor who chanced it, so now I couldn't even buy a smaller replacement.
Local vendors didn't have anything nearly the same format, so I gave up and bought a LEZYNE LED Macro Drive 1300XL. Inside there are two 18650s wrapped in a pack that has a plug, so should they die, you can replace the battery without soldering.
Yeah, I really like that Fenix lights just take a Li-ion 21700 or 18650 (and they have a little caddy to adapt the latter for the former).
However, the manual is very specific about only using their specific batteries and not just arbitrary batteries of matching size and chemistry (generic 18650s). I'm currently trying to get some information out of the manufacturer about whether there is risk of damage or they're just trying to avoid people using shitty batteries and blaming them for a bad experience.
(The manufacturer is fenixlight.com, but the seller is fenixlighting.com. It's kind of confusing.)
Was it a protected cell? They have a little circuit board on one side, sometimes you can see it through the shrinkwrap.
Both were protected - it's just that the battery I bought was genuinely the wrong size - it wasn't 60mm in any axis.