36v to 48v Compatability

[Arby]

Hi, I've got an off the shelf 36v Burisch bike and am looking to upgrade the electrics to a 48v system to give me a little more top speed (offroad). Obviously I'll need a new battery, charger, motor and controller but are components like break levers, throttle and PAS compatible with the higher voltage and higher (<50A) current?

This is my first foray into self-build so appreciate the advice.

 

[Deleted member 4366]

Do you already have the Burisch controller without speed limit. If not, you'll need a new controller to do any upgrade.

An easy starter is to upgrade only your battery to 44v. You can do that by adding a 2 cell booster pack or by replacing the battery with 12S lipos. A 36v controller should be able to take it. That would give you 20% more torque and speed.

Another step with or without the battery upgrade is to solder 30% of the shunt in the controller. That will give you 30% more torque, but it would be best to get a better battery do do that.

If you want a very significant step up in power, a BPM motor and one of those frame mounted batteries with the included 20 amp controller, LCD, etc from BMSBattery could make you go pretty fast with good hill-climbing too. You have decide on battery voltage and motor RPM to get the speed and power you want.

All the ancillary stuff like throttles and PAS are standard and will work with any system, except that the LEDs on the throttle will indicate wrongly if you have them

 

[RobF]

Seems to me selling the Burisch whole and building a speed pedelec from scratch might work out cheaper, depending on the cost of the donor bike.

No worries then about compatibility.

 

[trex]

can someone tell me what would happen to the electrics if you use 2 x 6S lipo bricks (44V) and there is a short in the power wires, either inside or outside the controller? there seems to be nothing in the system to stop a fire.

 

[Deleted member 4366]

I've done it loads of times, so I know what happens. The point of contact gets instantly vaporized, so there's a very bright plasma ball, a loud bang, and that's it. You end up with a large black patch of copper oxide on your tee-shirt too, and if your fingers are too close - like the photo below. You'd only get a fire if maybe the sense wires shorted because of the lower voltage and higher resistance of the thinner wires.