Heated Grips Cheap Fix

When I bought my Suzuki SV650 I was determined not to fit heated grips. The bike was intended for summer fun and thus they were not needed. Well…. the best laid plans and all that. The SV was pressed into service in January last year when my CBF wasn't on the road (I didn't MOT it, I can't remember why) Anyway after a short time I realised I needed some heat. I searched the garage and found a pair of Honda heated grips that my brother had given me. I didn't have the controller so just fitted a switch that means the grips were on full power when they were on.  

 
This worked fine for the winter. But, this being Scotland, a little heat is welcome at just about any time of the year. If it's cool but not cold I like to have the grips on low for a little background heat. So I needed some way of regulating the power to the grips.

I could look for a Honda controller - I don't know if this is sold separately. If so it would be expensive. Oxford controllers are available and I could try to get this to work with the Honda grips. But in the interest of trying something different (and saving a few quid!) I bought a cheap DC motor controller. And when I say "cheap" I mean £2.28 cheap! 

This unit works on 5 to 35 volts at up to 5 amps. The grips draw 2.4 amps so this should be within its capabilities. It claims to work in the range of 1%-100%. The unit uses pulse width modulation. What it does is switch the power on and off very fast (10kHz) and varies the "off" time to control the output. 

 
The first thing I did when the unit arrived was to test it. I mean, this was something all the way from China for less than the price of a cup of coffee. I wired it up to a fan and it worked fine.

I thought about how to fit it to the bike. It's just a circuit board with no enclosure. I used a length of plastic pipe and used heat glue to attach ends. I wired it all up this afternoon and it's working well.

 

My controller looks unobtrusive on the bike