Nâh, there’s some electronics in those handlebar lights, to boost the 1.0 - 1.5 Volts to the 2.0 Volts you need to light up the LEDs (actually it’s 1.9Volts for red LEDs).
If you give them 3.7 Volts, it still wants to boost it, because it’s a boosting circuit…
Heat will be generated for sure… But not for long…
I'm guessing these are 1.5 volt Li-po ??? like you say they are .
how about a link of the batteries you bought ?
Ebay is not your friend .
odd stuff ......The link is in no way an endorsement
I hesitate to drop the link on the form at all.
again worth repeating
Ebay is not a noobs friend
welcome to BLF
You could use this B3603DC-DC Works very well but you would have to terminate the charging yourself.
Can be got on Aliexpress.
With those Kentli batteries the ring on the positive end probably connects straight to the li-ion cell inside for charging.
Your xtar VP1 set to 250mA would work if you craft an adapter cap that slides over the positive end of the Kentli.
Xtar MC1 (at $5.95) is a great Li Ion recharger…500mA charge current…takes forever for larger batteries…
Just be careful with the micro USB connector
It can charge batteries from 16340’s on up to 18650’s and everywhere in between (love those slider chargers)
I’ll just get some springs or whatever then and use my VP1, just like Helios suggests. Thanks!
Just be sure the 1.5v button contact is covered well. Don’t want to take the risk that accidental contact might damage the Kentli.