have one of these [img] 
[/img] since getting my duster bike,i cannot find a good way of securing the battery.my 70mm stem is too small to attach the battery to.when i went out on a night ride yesterday,i fitted the battery on the top tube (right next to the stem),but the battery kept moving about.sorry to be stupid,but any tips would be most welcome.thanks 🙂 p.s i am going to save for an exposure light,so won't have the problem in future/more power 😀
you need an extension cable
then you can fix it more securely further down the toptube
add a bit of PVC sticky tape too
......try Chainreaction etc
As bighendo mentioned, get your self an extension cable. That'll give you more options for mounting. Ive found the top tube perfect for hanging such batteries. A thin bit of rubber, foam or velrco where the battery comes into contact with the frame will help keep it in place!!!
I fit my DX battery pack on the top of a 60mm stem, brought a 1m length of 1cm double sided velcro and wrap it around the pack and the stem tightly 3-4 times, very secure IMO.
Also cos its on the top of the stem it stops it getting covered in gunk
you need a second strap to hold it to the downtube as well as the top tube.
on top of the stem + some extra velcro
I strap my Vision battery on a 70mm stem with velcro and a couple of straps each made up from a spare Crudguard rubber band threaded through an old stamped aluminium canti cable hanger - the rubber band stretches round the battery/stem and hooks back onto the hanger lip. Got no photo I'm afraid.
I run mine inside a bottle cage with the extension cable. The cage is there more to protect the frame and give the battery something flat to sit on so it doesn't slide around.
I hang my Hope battery from the top tube without an extension. Use a zip tie done up pretty tight to stop it from moving around.
The stretchy velcro things supplied by Hope are virtually useless imo.
My frame has cable guides for a dropper seat post. I put my battery around the seat post, then use the guides along the top tube for the wire up to the light on the bars.
Hang it under the stem?
Maybe use cable-ties as a temp solution.