Bafang BBS02 (B) battery wire guage

[robwalley]

Because I wish to build a new ebike, replace a faulty magnetic cadence disc and circuit, have a smooth Lake Constance trip (shortly) and have a 'B' version, I purchased a replacement BBS02B 36v 500w for my current (only flaky up very steep hills pulling high amps on assist only) version one.

Took out my old motor to be repaired later and noticed the wire guage to the battery is almost half on the newer B version. I can only assume the old version was over the top.

Anyone have knowledge or comments on this, an online calculator suggests 18AWG which I'm sure it's not.

 

[Woosh]

I use 12AWG for that motor.

 

[Fordulike]

As Woosh says, 12AWG will be fine.

http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

 

[Nealh]

What did you measure the wire dia as ?
18awg would be about 1 - 1.1mm max 24a rating, typically 18 - 20a.

 

[robwalley]

I use 12AWG for that motor.

What do you mean, "You use" ? Why change what comes with the motor, you would have to crank it open and change it, mine comes with around 30cm terminated with crimped bullet connectors. Black and Red cables are 2.5mm diameter (including sheath) - not sure how that would relate to AWG unless I strip to wire and measure.

 

[robwalley]

What did you measure the wire dia as ?
18awg would be about 1 - 1.1mm max 24a rating, typically 18 - 20a.

Ah, that's more comforting, I wanted to test with crimps on before stripping cable (warranty), so tricky to measure the bare diameter, like I said 2.5mm with plastic sheath, so looks OK.

 

[robwalley]

Harness cable is also 60mm shorter and when you have a custom top harness cable with only the connectors you want and spot on length, it's a pain in the backside.

 

[Woosh]

What do you mean, "You use" ?

to connect the battery cradle to to the motor.
https://www.ebay.co.uk/itm/12AWG-12-AWG-Silicone-Wire-Pair-50cm-500mm-Black-Red/250919535396

 

[robwalley]

to connect the battery cradle to to the motor.
https://www.ebay.co.uk/itm/12AWG-12-AWG-Silicone-Wire-Pair-50cm-500mm-Black-Red/250919535396

I know this, but the motor already comes with cable which is terminated inside the case somewhere, you appear to be suggesting opening it up and replacing the whole length.

 

[Woosh]

I know this, but the motor already comes with cable which is terminated inside the case somewhere, you appear to be suggesting opening it up and replacing the whole length.

no, only from the battery terminals to the crimps on the motor cable.
If you make the battery lead yourself then you don't have to buy silicon wires, cut a piece from the power lead of the motor to do this.

 

[robwalley]

no, only from the battery terminals to the crimps on the motor cable.
If you make the battery lead yourself then you don't have to buy silicon wires, cut a piece from the power lead of the motor to do this.

OK, understood, but if the 30cm motor cable is 18AWG (I'm not saying it is), whats the point of making a short 12AWG to connect to it?