Originally Posted by
JPMacG
I think they say somewhere in their advertising that the battery inside the holder is a Li Ion 18650. I don't think they say if it is the 'protected' type or the 'unprotected' type.
I can guess a few reasons why they might put it in a custom holder...
- Make some profit
- Control the quality, capacity and type of cell
- Assure reliable electrical contact - better than you would get with spring contacts on a bare cell.
- Make it easier to swap batteries during a ride
- Reduce legal liability. Li Ion cells have been known to 'vent with flame' if charged improperly. The holder forces us to charge it only using their built-in charging circuit.
My Lezyne light comes with a bare cell, and I assume it is protected, and they say to only use their own batteries. My guess is that the charging circuit depends on cell protection, and usage time depends on the maH rating. At the same time though there is nothing to stop you from putting anything else in. Points 3&4 above are pretty weak, we've been swapping our own AA & AAA for years without problems.
But a lot of products come with their own proprietary version of these batteries in special cases. It gets annoying when you can find the charger for you camera, cell phone, whatever, and these things still aren't anywhere near universal.