I have 4 spare 18650 batteries that i’d like to put to good use, does anyone have any recommendations for a good off-roading MTB front light to use them with? I am looking for something cheap and cheerful. I had a Skyray King torch which was decent, but the threads stripped so it’s useless now, so now I think i prefer something more bike specific.

You could get one of these battery holders & then just find a suitable lamp unit for it?

4×18650 battery holder

Or use them for a chargebank for your phone:

4×18650 charge bank

I haven’t used either of these so can’t really comment on their quality or functionality. There’s probably lots more options out there.

I lashed this together from a qr water bottle mount and a sky ray lamp.
It is bright and you can change the batteries if on a long run.
Not as good as my exposure but £15 all in.

Those battery holders linked above are no good I have one.

They have springs for one end of the battery contact and flat metal for the other.

On rough ground they momentarily disconnect, of course turning your light off.

You need one of these battery holders, which has springs both ends of the battery contact, meaning the battery floats on springs and doesn’t disconnect:

https://www.ebay.co.uk/itm/8-4V-Waterproof-USB-4x-18650-Battery-Storage-Case-Box-For-Bike-LED-Smart-Phone/133513923420

You can also get a 6x cell version.

I’ve been using one the past year+ and no worries. I scavenge cells from old laptop batteries at work, using just one or two cells is duff in them and you get really high quality cells out of them.

I use these head units, these are latest and most efficient XML-T6 emitters, as used in much pricier branded lights etc. I use on on helmet and one on bars, the one on the bars has developed a rattle after a years use but still works.

https://www.ebay.co.uk/itm/Cree-XML-T6-Double-LED-Bicycle-Light-Bike-Front-Headlight-USB-Rechargeable-Light/184420237168

Wzzz, how do you attach it to your helmet?

Wzzz have you had an opportunity to compare that to a name brand light such as a joystick?

Wzzz, how do you attach it to your helmet?

Remove the strap from the headtorch adapter

Zip tie the remaining mount to your helmet. I used a heat gun just to get a curve in the mount so it fit my helmet well.

Wzzz have you had an opportunity to compare that to a name brand light such as a joystick?

My riding mates all run various hope lights.

The Hopes are brighter – similar XML-T6 emitters (maybe different variation) I think but better optics and may be over driven with better heatsinking, oh and they and get repaired for free.

But mine was £12 and has lasted a season of night rides so far includign some torrential downpours.

I have one on me bars and one on my helmet.

I run one on the battery case I linked with scavenged laptop batteries, and one on the pack the lamp came with – this one lasts just under 2 hours on full whack now, starting to fail but it is certainly very cheapo cells.

I’m thinking of building a 2-cell pack with expensive new batteries to mount on my helmet, as having the battery in my pack and the wire trailing is annoying when I need something out the bag and makes it impossible to chuck a waterproof hood up when waiting.

For the price the Skyray King is great, but i’ve had two now and they’ve both broken on me. The Strobe mode is also a little big dazzling, when I used it on city streets I stuck a white-opaque sticker on the lens to reduce glare and diffuse the beam.

@wzzzz thanks for the info on the springs, thats definitely something i’d have missed but will look out for. I already have a twin 18650 head lamp (which I can probably tie to my helmet) so the lights you linked for the bar look like just the ticket