This company, Gammatronix, make several types of battery monitors for various situations. The one I went for is fully waterproofed, and is designed to be velcroed/zip tied, pretty much anywhere. I fitted mine alongside my gear indicator which utilises a bolt at the back of the facia. The 3 wire harness is over a metre long to easily reach the battery. The 3rd yellow wire, is connected to a switched live , so that the unit can differentiate between when the bikes running or not, to give the relevant display. The Led displays one of 3 colours when the bike is running, permanent green=ok, red=overcharging, and yellow=under or no charge from the reg/rec. When parked up it flashes green ,ok, or yellow if the battery needs charging. The current drain is minimal, can't remember what as the instructions are in the garage. I fitted a mini blade fuse holder in the +ve lead to the battery, fused at 5 amp, as per instructions.