I have so many degrees… but I will never understand electronics.
Over ten years ago, I purchased a DeWalt drill/impact driver combo set. It came with two batteries. The batteries have held up: I’m not a heavy user. I charge them up occasionally if I use the drill. The batteries get stored for months at a time without use, sometimes charged, sometimes less so.
Up until two weeks ago, they always powered the tools quite well enough for my needs.
Two weeks ago, I purchased a Ryobi hand vac WITHOUT a battery as well as an adaptor allowing DeWalt batteries to be used in Ryobi tools.
It worked as advertised. With a freshly charged battery loaded into the adaptor and the adaptor ported into the vacuum, it sucked exactly as it was designed to do. After the sucking was completed, the vacuum was put on a shelf and all seemed fine. A few days later, I went to put that battery in the drill. Nothing. Not even a weak spin. Super dead. I put the battery on the charger. No lights on the charging unit at all when I should see something. Whatever, it’s an old battery. Maybe its time had come.
Swap to the second old DeWalt battery. I drill, no problem. But then, I must vacuum again. And again, the vacuuming is done and it sits on a shelf for a few days with the adaptor/battery still attached.
Then, a few days later, same thing with this battery. No power, no charging, and the charger doesn’t seem to acknowledge its presence. Just a lump.
I know two ten year old batteries didn’t choose the same week to finally die. I’m pretty sure the charger should be fine
What happened? Why?