I tucked a small voltmeter up behind the instrument panel and underneath the front headlight assembly on my bike. It works and fits great in that space - visible but out of the elements and not in the way. It's made by a company called Runleader and it's actually for golf carts and forklifts (12 to 16V) but really looks slick and does the job. I like the fact that it give you the range of voltage and a green light below to show you're in the normal operating range for voltage. It comes with high adhesive tape and a small set of bolts and nuts that threads the unit on to the surface you want to mount it on. The unit is the Runleader RL-B1006 and comes from China.