Before I forget- did you know that you could electrocute yourself by working on an EV and not following the proper safety measures? If you are unsure, don’t try to work on an EV conversion. And now back to our regularly scheduled programming…
EV’s have two types of wiring; high voltage and low voltage. High voltage wiring comes from the battery and powers the components that propel the vehicle. Low voltage wiring controls items that you are familiar with already- the lights, horns, turn signals, and a few other things.
Wiring isn’t photogenic, so I’ll do my best to explain the wiring with the help of photos.
Let’s talk about the power flow:
Power comes from the battery. I’m using a custom-made 72 volt lithium-ion battery pack from Amorge. Amorge makes custom packs for EV’s; tell them the space dimensions and voltage and they will make you a pack that fits exactly. This battery weighs a LOT and will produce 72 volts at 380amps for a continuous period. That’s more than enough to propel the scooter as fast as I want to go (over 65+mph), with a range that I estimate to be 100 miles. The battery can be easily unplugged and slides in and out on rails.
Power leaving the battery runs through a 400amp blade fuse. The fuse protects the downstream wiring.
The next stop is the high voltage battery disconnect switch. This allows me to shut down power to the bike before removing the seating cover.
From there the power flows to the contactor. The contactor serves two purposes:
- Added wiring protection;
- The ability to add a key switch to turn on and off the bike from a low voltage location like the handlebars or a key fob. In my case I’m ditching the key and going with a remote key like a modern car.
The final high voltage stop is the controller. As the name implies, the parameters set at the controller decide how much power goes to the hub motor. I’m using a FarDriver 72680 controller. The 72 stands for volts and 680 are the amperage rating. It also has high and low voltage input and output connections for things like the throttle and speedometer.
The Setup in Photos:
A view from the top:
A view from the side:
From High Voltage to Low Voltage:
The high voltage system is converted to 12 volts with the DC-to-DC converter. A 12 volt line runs out and goes to a power distribution/ fusebox. It always bothered me that Bellas were missing fuseboxes so I’ve solved that problem as well!
A Note on International Setups:
I’m in the USA and the rules about wiring and inspection of EV’s are not as advanced or stringent as in the EU or Great Britain. In those areas the controller must be certified to pass TUV and MOT inspections. My understanding is that the Fardriver has been certified for use in both locations. The other difference is that all high voltage wiring must be orange. With advance planning that shouldn’t be a problem.
Next time we’ll talk about low voltage wiring and the controls setup. We’re almost done!