Battery location on frame for mid-drive.

[Joaquin Suavve]

In my thread regarding the Ebike I am building, several people gave my idea of mounting the battery below the bottom bracket and down tube.. "A through finger wagging".

If it is "Safe & Sane", why not and Happy 4th you guys (please respect the dogs/ animals around you)?!?

Have any of you ridden a bike (with correct geometry) trying the battery above the downtube AND mounting the battery bellow?

If so, please share!

 

[raylo32]

As long as you have clearance from the tire throughout the fork travel and have it secured solidly it would work. But don't expect to just have a shark style battery bracket and be able to pop the battery on and off. The forces seen from hitting bumps while riding would likely rip the battery and/or the bracket right off. But maybe with a Bottle Bob to hold the bracket securely and some extra strapping or duct tape around the down tube to hold the battery more securely.

 

[Joaquin Suavve]

Duct tape & bailing wire are ALWAYS my first line of defense!

 

[Tony01]

The best location for weight on a bike is as close as possible to other weight like the motor and rider. Batt in the front triangle is best

 

[dgc]

I drill the down tube and insert threaded rivet bushes, you can get an insert kit cheap. I then use 20 mm or 25 mm black velcro straps as second line of defence for holding the battery, I have held 10 ah and 14 ah 36V batteries by this method but not a jump rider only a cross country or track rider.

 

[hillslayer@]

I run 2 batteries one on top of the downtube and one below which rests on the Bbso2. Use a rachet strap to get them tight together hard tail mountain bike handles great with this setup.

 

[dgc]

You can make it tidy, not all mine, just examples of what can be done.

 

[docw009]

I tried this once, but Hailong cases vary. Some have plastic locking tabs that use the full case length. Some use less than half. I've seen the tabs break off in normal usage too. Velcro straps are needed for insurance.

The same applies to the mounting bolts on the cradle. Many are held only with two screws. You will want to use a steel bracket securely attached to the frame, and drill the bracket to take at least three screws for the cradle. This bike uses two 5mm screws for the water bottle plus two metal hose clamps to hold the bracket. Three straps on the battery.

In the end, I didn't want to deliver a bike with what I consider is a problematic battery mount. I switched to a rack mount on the back.

 

[dgc]

I tend to use small bottle batteries 36V / 48V 10AH which have a aluminum full length mount along with a pair of 20mm velcro straps. I do fit three thread inserts to fit the mount to the frame, and these batteries only weigh a around a couple of kilos.

 

[E-HP]

The same applies to the mounting bolts on the cradle. Many are held only with two screws. You will want to use a steel bracket securely attached to the frame, and drill the bracket to take at least three screws for the cradle.

Not a permanent solution, but a hack to get a little more support that 2 screws: I used a Cottor pin and a 3/8” heavy duty zip tie to secure one end of the cradle for the time being, since I have a new battery on the way that won’t use this cradle.

 

[Chalo]

I know Hailong packs pool water when you mount them upside down. So you have to keep water out of them if you do that.

 

[dgc]

My long range e-bike with an inverted Hailong battery, I tend to be a fair weather rider my old bones will not take the damp, agree with water getting in, so may 3D print some cover sections to go between the down tube and the battery to help weather proof it to some degree.

 

[Joaquin Suavve]

Thanks for the input gang!

I have 3 shark battery brackets coming with my King Shark battery with the plans for using one on the electrical assembly bread board that I plan on building, one for a typical "above tube" mount, and the third for fabricating into a "under tube" battery mount.