LinkStyle Car Digital Voltmeter, Waterproof DC 12V LED Digital Display Voltmeter for Car Motorcycle Voltage Volt Meter Gauge

The cable supplied is of a decent length and for a cheap volt display to give easy monitoring of battery condition its very accurate only reading 0.1V above the actual voltage when measured against calibrated professional equipment. Very happy.

Unlike some, this one is bright and easy to see. Pleased I bought it.

Tended to read 0.1V high so added a 100 Ohm resistor in series with +ve lead. makes no difference to function but drops the voltage by 0.1V to correct the reading. Might need to select your own resistor value spending on the unit you have.

flashes when it drops below 12 vaults that’s Not in the description ! But that’s not a big problem for me !

I wired this gizmo up to tell me what my 12v battery is doing whilst running my lights in my shed with a caravan charger attached too. Recommend it to everyone to use as so easy to use and wire up

I have put this close to my motorhome engine battery (which is under the driver's seat on a Transit) so I can quickly see the starter battery voltage as soon as I open the driver's door. I can easily check if it needs recharging if I haven't used the vehicle for a long time.

The display doesn't show the immediate voltage of the battery after a change in condition. When the bike is cranked the voltage momentarily falls to say 10.8 volts, just for a millisecond, and then returns to mid to high 13+. But the display still shows the lowest voltage it measured during cranking, this continues for several minutes. Likewise when the bike is charging the battery, the increased terminal voltage is not instantaneous, still showing 13+ when actually the terminal voltage is 14.2+ So not so great at letting you know exactly what the battery/charging circuit is achieving, right now. Okay if your just wanting to know the voltage/state of a battery not used to start an engine or under charge, but not good for instant feedback of your battery condition.

Nice small unit, easy to fit. Can't comment on accuracy as have not compared it with a known standard.