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 renewable 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.
Parts required
- 3mm plywood sheet (around 1/3 sheet of A4)
- Wood glue
- machine screws (around 12mm long)
- 2 x M3 nuts
- 4-digit LED display
- I used this one from Sun Tek Store (but available at other places including eBay):
- http://www.suntekstore.co.uk/product-14002344-036inch_4_digit_digital_panel_voltmeter_0-33v_red_led_voltmeter.html
- On/off switch
- I used this one from Sun Tek Store (but any switch would work):
- http://www.suntekstore.co.uk/product-14001517-black_mini_size_spdt_slide_switch.html
- 2m of twin (red/black) cable
- ‘Cigar ligher’ type plug
Tools required- Access to a laser cutter – such as at your local hack space
- Soldering iron and solder
- Side cutters or wire strippers
- Posidrive screwdriver
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