What's the best location speed controller?

[piotrmacheta]

Can anyone advise the best practice for wiring lengths?

I have an eZee hub and ecrazyman 30A 48V controller fitted to my mountain bike. I have the battery on a rear rack and have a choice of putting the controller near the hub (front of frame) or on the rack next to the battery.

Which is the best place from an efficiency/losses point of view? My reckoning is that it's probably better to keep the battery to controller wires short to avoid voltage drop to controller but is it likely that long wires to the hub will affect the performance more?

From my tests I note that the flat speed current is about 8 amps and max 22 amps at start-off. The cable I'm using is 30 amp rated silicon wire and it's about 1 metre long from battery to controller.

Any advice?

 

[OneWayTraffic]

If I recall my physics correctly, the resistance in those wires will be in the milliohms. Even if running a 20amp current through them you wouldn't be seeing a fraction of a volt of drop. I'd pay more attention to the quality of your connectors (a lot of losses are at poor conections) and place the controller for other reasons.

You want to keep the controller in a place where it's exposed to wind for cooling, but sheltered from the rain, road spray. Under the seat is a good bet.