Newbie - How to plug a wattmeter to my bike?

Aushiker

Pedelecer
Bringing this thread but from the dead as I am looking at adding a Turnigy 130A Watt Meter to my build of the Bafang BBS01. What has me confused is that the BBS01 has the controller built into the motor so the cable from the battery effectively goes directly to the motor.

Would wiring the watt meter so the cable from the battery went to the meter on the source side and then out on the load side to the motor work?

Am I making sense here?

Thanks
Andrew
 

Alan Quay

Esteemed Pedelecer
Dec 4, 2012
2,351
1,076
Devon


Here's what I did with mine. This way I can drop it into any of my bikes to see whats going on.

All my batteries have Anderson powerpoles.
 

Aushiker

Pedelecer
Yes. You can use the same connectors as your battery to controller connection so that you can wire it in or out. You need to use 30 amp wire to avoid unnecessary voltage drop. 14g silicone wire is the best. If you want the wattmeter on your handlebars, you should consider mounting the shunt remotely.
http://www.pedelecs.co.uk/forum/threads/the-best-value-wattmeter.16869/

Thanks. I had seen that thread before but it went over my head. A re-read is helping :)

I have just ordered some 12 AWG silicone wire to build the power cable. Would this work? That said I think I will have a go at the shunt.

Apparently the local electronics retailer sells a remote shunted meter, but for a price. Might be an option if I can find it at lower price, otherwise practicing my soldering skills is on the cards.



Regards
Andrew
 
D

Deleted member 4366

Guest
12g is better electrically, but it's a bit harder to solder, and more ugly if you have to run it anywhere where you can see it.

There's also a half-way house way to mount the meter. It only uses the negative (black) wire to measure the current, so you can run the red directly from the battery to the controller, and only the black through the meter. Then you need a thin red from the battery positive to the red on the source side of the meter to provide power for the meter. You don't need a red return from the meter. If you look at the pictures, you'll see that the red runs straight through, but has to make contact to provide power for the meter.

To summarise, this method doesn't involve any extra wiring or soldering. It means two thick wires and one thin wire to the meter instead of four thick ones, so it's about half as ugly and half the losses.