This voltage monitor has been designed to remotely display battery voltage so that people monitor and maintain their batteries easily. It was designed for use on off-grid reneable energy systems (such as my solar PV system), but it would also be useful to anyone who has a lead-acid battery, such as caravans, boats and cars.
It is designed to plug in to a car ‘cigar lighter’ socket and display the voltage on a remote LED display. Here are the plans to make your own.
- 3mm plywood sheet (around 1/3 sheet of A4)
- Wood glue
- 2 x M3 machine screws (around 12mm long)
- 2 x M3 nuts
- 4-digit LED display
- I used this one from SunTekStore (but available at other places including eBay):
- On/off switch
- I used this one from SunTekStore (but any switch would work):
- 2m of twin (red/black) cable
- ‘Cigar ligher’ type plug
For more detail: Battery voltage monitor