Knowing how your charging system is functioning is a vital piece of information, especially on classic machinery that may still be using some original electrical hardware. This Compact Digital Voltmeter from Aerostich tells the charging rate of your bike in real time. Mount it to a fairing, instrument panel or triple clamp. It’s easy to install by connecting to any circuit that is powered when your bike is running. $13.
$13 Beer slips is not a bad price, but you can get them cheaper on eBay, usually from China, Many on the Buell forum modified their instrument clusters and there is a DIY set of instructions on how to open the cluster and how to install them in a unused dead space. My advice is if line of sight, DONT use red display. Even this unit shows a check mark for colors. Its distracting to have a bright red orb in sight line while riding, red should only be for danger or warning lights. If not visible while riding then red is perfectly fine. (PS, I bought a dozen of them for my other bikes as well, Voltage is more useful than amps in my opinion on a bike or car)