Review on Charger SUPERONE Adapter Voltmeter Samsung by Peter Boisvert

I live in an RV and constantly charge my iPad + iPhone. This is a good charger but the voltmeter is a trick to sell this charger among other things. If I don't charge anything, the displayed voltage is 0.1-0.2 volts lower. When I plug in my iPad, it shows the battery is 0.3 volts less than the actual one. When I plug in my iPhone (now charge both at the same time) the voltage drops 0.5 volts below the actual one. How do I know? When this charger tells me the starter battery voltage is 11.9 volts, I worry that I won't be able to start my van and open the hood to find out the actual battery voltage, which is always 0.5 volts higher, what means that the battery is in good condition and starts without problems. Now I know I can live with that. But there are still times when I see that dreaded 11.9 volts and immediately crank the engine to charge the battery, which is a huge waste of gas and money. So if you are thinking about buying this charger, you should be aware of this issue.