4PCS 2S 2 Series Lithium Battery Level Indicator Capacity Module Ni-MH 8.4V 4 Sections Blue LED Display Electric Vehicle Battery Power Tester Li-po Li-ion

Works at intended and very bright. I took off 1 star because of miss-leading picture described that this 3s unit can measure 1s. It DOES NOT work with 1s. Plus, on 3s units that I received, there are six holes of (+) and (-) combined in which 2 holes are not labeled and other 4 do. I've tried different combination but it does not work with 1s. Only the parameter lighted up red, no indicator bars shows. Again, seller should delete that picture that shows it can measure 1s or 3s to avoid miss-leading for other customers in the future.

Works OK, but no instructions. I wanted to know more, so I measured the current draw and found it to be 35mA, which is very high for a battery checker. If you leave it turned on, it will drain the battery. So, you need to use a push button switch to momentarily check battery level. I think the LEDs are much too bright, adding to the current draw. There are two PCB pads labeled "switch", what are they for? They are not for the switch I suggest, because it works without connecting those two pads.

I got the the 1s and used one fully charged 18650 lithium ion battery and am only getting the red leds to light up

Showed full charge up o the second the batteries died

Very Good Deal

Set one up on a 3s configuration just to test and it has been fairly accurate. there are two unpopulated pins marked SW1. I thought this must be a place for a momentary switch. I was wrong, it's a place that if you put a switch on it you will let the magic smoke out. Live and learn.

TIPS:* ONLY WORKS FOR 11.1VDC to 12.6VDC.* Consumption current is *5 milliamps* so don't leave this connected in series and always running. It *does* create a load on the battery and will drain it faster. Also will get warm/hot to the touch if left on too long. USE A MOMENTARY SWITCH!* There are at least 3 different board versions being sold. The positive and negative pads for the batteries have been moved between the board versions.* Works with LiPo, Li-Ion, Ni-MH, Lead-Acid, and Alkaline batteries.I wanted to create an 3-cell 18650 battery pack for my FPV goggles that I use for my racing and freestyle drones. I needed a way to see the approximate remaining capacity of the cells. Sure I could have went with something that showed the exact voltage but this works great when used with a momentary push switch.

Awesome little displays. Seem accurate and well built