SUPULSE lipo Battery Checker Battery Tester Controller Tester Voltage Tester for LiPo/Life/Li-ion/NiCd/NiMH Digital Battery Capacity Checker

Using this to monitor my LiPo batteries when draining them before storage. I use an automotive turn signal bulb to drain my charged LiPos to bring them down to a safe voltage for storing them as my charger doesn't have that functionality built in. While doing this, I want to make sure I don't inadvertently bring the batteries too far below the safe low voltage. So, I set the alarm at 3.7V and connect the bulb to the battery pack. Once the alarm goes off, I disconnect the pack and put it away. The only downside I've found to these alarms is that they aren't accurate and are off by 0.1 ~ 0.2V on the safe side. So, the alarm set at 3.7V goes off when the actual voltage is at or above 3.8V per cell which actually is preferable and isn't a problem for my use case.As others have stated, it is very loud. The case simply separates into 2 halves and the actual circuit board pops right out. I may at some point disconnect one of the alarm speakers or add some padding to soften the noise.

Works great on my RC Boat. Appreciate the alarm points you can set for low battery voltage.

I compared the voltage reading from this little device with my fancy dancy digital meter. This was very accurate, only 0.01 volt higher. You don't really need that accuracy bur it could be useful someday. My only complaint is that the common connection point isn't marked. It's to the left when the printed name is facing towards you.Overall, a good value.

Checks battery voltage as it should and it's small.

Does what it is supposed to do and seems to be accurate. I would recommend this product!

This little battery tester works great! As others have said, the alarm is pretty loud, but that lets you hear it from quite a distance away. External case is a nice protective feature, but I didn’t want the extra weight, so I just removed it.

Works great worth the money

These are easy to use, and the alarm is very effective. They are not easy to read out in the sunlight, though. You have to shield the sun to see it well. That's not a big deal. However, I had them set to go off at 3.4 volts, and they did. But when I hooked the batteries up to my charger later, they were all reading 3.6-3.7 volts. So, that makes me think maybe these aren't exactly accurate, but I'm glad that if they are off it's that the battery is more charged than it reads rather than less charged. So, I'll probably just turn them down to 3.2-3.3 volts and see what they read next time.