I use one similar to this:
https://www.screwfix.com/p/rac-comp...gclsrc=aw.ds&dclid=CNbn7YjI9NgCFUmkUQodXA8H6w
That one may have a car type 12V plug on it, but you can get ones intended for use with bikes. The one I bought had an Optimate style connector so for powering it I have a fused Optimate type tail permanently wired to the battery and tucked up out of the way above the starter motor. It can reach either wheel from there with the length of lead it came with. These things need a high power source, probably about 10 amps so I don't think you could power it off the bike's 12V socket even if it had the right connector.
Mine has been 100% reliable and had a fair amount of use due to needing to top up a slow leak on holiday.