Board Thread:General Nerf discussion/@comment-45439975-20200410000856/@comment-27306930-20200623153908

Yes, that’s an issue with those batteries. I normally insist tell nerfers to get protected IMR batteries. They’re super safe.

But the easiest way to monitor these IMRs is simply to listen to the flywheels. When you hear the RPMs drop, it’s time to recharge them. I’ve found similar batteries last a couple hours in normal game play. I carry multiple sets.

Optionally, you can get an inexpensive battery alarm and install it inside your blaster. It costs a few bucks and takes a little work, but it's the best way to monitor your batteries.

A decent charger like the NiteCore I2 will prevent over charging. So that's not a problem. And don’t ever short circuit them. It's just that simple.

Bottom line, I don't recommend unprotected IMRs for beginners. They're not dangerous, but if you're not paying close attention, you will ruin them. They're totally unforgiving that way, especially the 2.75 volt minimum. Once they fall below that for a fraction of a second, they're toast.