How I built a 12ah Battery for my BGT

If you have the Street setup, can you do a range test sometime? I'm curious about it. You did all this work but I don't think I see how far you can go. Thanks!

 

It just takes so bloody long to do, to be honest I'm sick of riding after 20 km. extrapolating my data though I think I would get 40 km.

 

I'd be happy with 40 km (~25 mi) if it could actually get to that point. Maybe if I lost 10 lbs that would also help My stock board can only get 16 miles with my normal usage, as in not purposefully trying to go super fast but also not gingerly sipping at battery power. I wanted to see if this battery build would make a big difference. It sounds like it does...but I just wanted confirmation that it could go that far. Otherwise what's the point?

 

Check out on instagram.. "longhairedboy'.. He's just replaced like for like in terms of size (stock evolve bamboo li pouches for 18650 cells)...

Better range, and "full use" of the battery (no sag towards the end).

 

Yeah, he is stacking the BMS though....

 

wait, stacking, like, damaging, or stacking like more than one?

 

Haha stacking on top of the motor controller.

 

Is that a bad thing?

 

Well not necessarily, but a lot of heat is generated from the motor controller, plus the first guy to try stacking them unfortunately had his board turn into a a flaming pile of carbon. We don't know if that caused the problem but we also don't know that it didn't.

 

I just got my board back from LHB, rode it for 1.5 hr straight with lots of hills, so far so good....

 

Nice. Keep us updated. I wanna know the range

 

?? (physically)

Ahh yep, I can see that in LHB's image now. You could do a shorter battery though eh? 10x3?

 

You can't get the required amps out of a smaller battery

 

Nickelberry,

Do you know what the required amp are? I.e. full load current drawn by the motors?
The spec sheets for the motors themselves max each at 36A - but this seems too high, it must be a factor of this maximum.

I read somewhere 5A is max draw......do you know how this relates to the motors spec sheet of 36A each?

Would be very helpful if you have any insight into this for a project I am working on.....

Thanks

 

I built mine to handle 70A (before it starts getting warm) which is around the max. 5A would be cruising slowish on flat ground.

 

Thanks - that makes perfect sense,

That would be both motors at max from their specs - is there a way you know of to calculate max safe current to draw? For the stock battery / your own custom one (which is awesome by the way !!! ).

I am considering various motors etc - and their effect of they draw additional current (besides reducing range) - assuming the BMS can handle it of course.

 

How and where are you shaving 10mm off the wheels to make them fit?

 

Bigger question is where to get the wheels in the first place

Where is off the inside of the wheel so the belt clears, and how is anything from with a utility knife, sandpaper, or lathe (with substantial variation in quality depending on which of the three ways, and who is doing it)

 

Skully is into it, I took about 10mm of them. My method was pretty hacky but it worked.

 

Nickelberry, could u upload the files for the printed spacers and tell us about how you extended the battery case? Did u use a heat gun to melt the plastic and stick both together and then sand it down? I am planning to do this mod soon too