Print instructionsPrint one each of the Main Body part and End-Stop part. They were designed to be printed in PLA, using 0.3mm layer height and 30% linear infill. No support material is required. The End-Stop stl file includes two bridge support features that are easily broken off by hand prior to assembly.Fitting and assembly1. Fit the Main Body to a water bottle mount on your bike using standard water bottle mount hardware, typically:- QTY 2 cap head screws: 5mm dia x 0.8 thread pitch x 12mm long- QTY 2 washers: 11mm O.D.2. Snap-fit the the End-Stop along the inside of the Main Body part. The fit is designed to be snug. To prevent over-straining the End-Stop during assembly, try to ease it into final position, rather than 'whacking it' into place.UsageThe battery is fitted in the orientation shown to enable easier reading of the digital voltmeter display while cycling. This orientation also positions the cable closer to the frame, which may in turn help prevent the cable snagging on low hanging fruit, or a misplaced foot.Before the battery can actually be fitted as shown, the sponge tape fitted to the case at manufacture by Magicshine must first be removed. If removed carefully, it can be reapplied to the opposite surface for safe-keeping for future use, should the need arise.Although the battery fits into the holder with a reassuringly snug 'click', I strongly recommend using the 50mm wide Magicshine supplied Velcro strap around the battery and holder for peace of mind - and safety.Nice to knowDuring its first test ride around town, the battery did stay firmly in place without any strap; but I wouldn't recommend it.With the battery and 50mm Velcro strap fitted, it's strong enough that I can lift my 11kg bicycle by the battery and holder.Since first publication, I'm happy to report that its undergone successful field testing at night over some gentle-moderate single track on the Malvern Hills, UK.The Magicshine MJ-828 battery was originally supplied with their 900 lumen HA-III SSC P7-C front light. It may also have been supplied with the MJ-808E front light and others too.