I have the same problem with draining batteries. It would be easy if I use alkalines, but I use eneloops and I managed to kill 6 batteries before I noticed what is the problem. The batteries are dead and cannot be recharged, because yn-e3-rt drained them completely which doesn't happen in any other device and is fatal for rechargeable batteries...
You can buy the cheapest slow-charger and charge these empty batteries for about 10~20 minutes.
And then, put these batteries to the smart charger. (Most of the smart chargers won't charge the 0~1V batteries.)




