Copied from elsewhere:
Get a full heated jacket (liner) with heated arms, neck and full torso, not a waistcoat or a jacket with partial panels
Get an easy-to-use heat controller
If the body’s elasticated, aim for a close fit
Wire direct to the battery via a fuse (leads often supplied)
Don’t bother with remote, battery-powered options. Your bike has a battery and charging system: make use of them.
Says it all really.
What’s mine? RapidFire. It came from America originally (when there was nothing close to as good available in the UK) but it’s no longer available, sadly. About the nearest is the excellent ’Warm’n’Safe’ who, if I wanted to buy a replacement, I’d buy without a moment’s hesitation.
Yup, I have the jacket liner, the inner gloves, trouser liner and socks, all four controlled independently of each other, by two dual heat controllers. Do they work? In a word, yes. Right down at -8C all day and lower when the sun went down in Luxembourg and the Vosges in mid-February and late November. I have two dual bike powered wireless heat controllers, which I simply Velcro to the clutch reservoir, one on top of the other.
What else? A long sleeved Merino wool top, then the heated jacket liner from RapidFire / Warm’n’Safe, then my Rukka jacket * and a Buff. That’s it. The RapidFire liner also acts as thicker EDZ ‘thin shell’, also excellent.
* I always take the linings out of my Rukka jackets and trousers. Can’t abide them and have no use for them with the heated liners. If I want to go out on a day when it’s not cold enough to use / take the heated liner, I just layer up and lob the thin shell EDZ in my tank bag as a final reserve. Job done. There again, anything is warm compared with a Casal 125 two-stroke, commuting down the A5 (when it had the third ‘suicide lane’) from London to Daventry, in a jumper and a bin liner..... and to think that bods moan like buggery over a bit of buffeting on their awesome WC steed.