Review on ⚡️ DROK 0-90V 100A DC Ammeter Voltmeter: Battery Capacity Amp-Hour Watt-Hour Power Time Multimeter with LCD Display and Hall Sensor by Derek Faseworld

The first unit was defective, after a few minutes the display starts to fail, then you have to unplug it for 30 minutes to get it looking good again. Revain quickly sent me a replacement that works fine. Is power coming in or out of the battery? It's hard to tell because there's only a tiny arrow pointing left or right. The manual says it changes color but I promise you it doesn't change color. Also, I have a 3000 amp hour battery and trying to adjust the total amp hour capacity one amp hour at a time takes literally forever. I dropped the 1500 Ah mark and just left it there, frustrated with a sore thumb. It may contain a relay to disconnect the batteries in case of over-voltage or over-current. I assume this will work fine, except don't expect it to drive a relay that draws 3 amps like my relay does, as it will burn out the transistor driving the relay. I looked at the characteristics of the transistor that was installed in this device to measure battery charge. It was supposed to withstand 3 amps but couldn't, it closed so the relay is now always on. Your best bet is to use a standard small automotive relay and use it to drive a larger relay that can actually handle the high amperage of a solar bank.