A couple of years ago I built a 3x cree xr-e q5 light which I am still happy with, but the battery pack is a bit bulky and isn't holding as much charge as it used to.

It is a 7.2V Nimh one, but I can go up to just above 10 volts with the new pack.

Anyone built a Li-Ion pack or bought one that can suggest a source and a reliable (safe!) charger?

Cheers
Paul

Try smudge on here
http://www.singletrackworld.com/forum/topic/chargind-dealxtreme-lights

2nd smudge.

3rd for Smudge 😉

Anyone built a Li-Ion pack or bought one that can suggest a source and a reliable (safe!) charger?

I have – using cells taken from laptop batteries bought on ebay. I (think I) know what I'm doing though – if you have to ask on here, then I wouldn't really recommend DIY with LiIon cells given how dangerous they can be. A 4th for smudge.

If you're running 3 Crees from a 7.2V pack you presumably have a boost regulator (Maxflex?), in which case yes you can go to 10V, but that's the maximum voltage your pack can be. Typically a nominal 7.2V NiMH pack will start off at 8.4V. You could go to a 7 cell NiMH pack, nominal 8.4V, max 9.8V, but a nominal 9.6V NiMH pack with 8 cells would destroy your LEDs when fully charged at 11.2V. Alternatively a 2 cell LiIon, nominal 7.4V max 8.4V would be OK, but not a 3 cell one.

a 4th… Smudge

I wasn't looking to start soldering bits together, rarely does it actually cost less. it is not worth the risk with these. I was really looking for a smaller alternative to my current pack but still waterproof and a safe charger. I will contact Smudge

I've been using a li-ion battery from these guys for the last 12 months with no probs. Good prices too!

http://electronics.shop.ebay.co.uk/Batteries-Battery-Chargers-/48446/i.html?_catref=1&_fln=1&_ipg=25&_ssn=victorstudio&_trksid=p3911.c0.m282

Thanks for all the mentions 🙂

Paul, send me an email with your details of what your looking for and I'm sure I can help you out.

Well done also on building your own light, you get a bit of a buzz factor when you go out nightriding for the first time using lights you've built yourself 🙂