Hi Guys,
New to this forum. Hoping someone might be able to help.
Bought a pair of Ryobi RB18L50 batteries and a charger for my nail gun a couple of years ago. Charged both the batteries and then didn't use the gun for some time. A few days ago when I tried to 'freshen up' the battery that wasn't left in the in the gun (the one that was left in the gun is fine), I discovered that it is cactus (0 volts on the output tags). The charger tests the battery for some hours and then deems it to be stuffed.
Did a bit of sniffing around on the Net and tried a few of the fixes suggested (there was talk that the battery had gone into a 'hard' sleep mode), but none of these worked and I couldn't get any charge into the battery either from the Ryobi charger or another power supply I have.
Next, I took the battery apart to reveal the cells and discovered that they were sitting at 0.9V, so I attached the power supply directly to the cells to see if I could get a bit of charge into them, which I did. By the time I took them off the power supply, they were holding a charge of about 18.9V. When I measure the output of the good pack, it reads 20.5V at the terminals, but the dud one seems to drop about 5V, which leaves me with about 13V at the terminals.
I've stuck it back into the Ryobi charger but it tested the pack and deemed it to be stuffed.
All that said, I'm wondering if the battery pack has a DC/DC converter built in to bump up the voltage to the tools and whether it looks like this is the part that is stuffed. I've tried to get a schematic of the charger and the battery, but to no avail.
Any sage advice would be very much appreciated.
Bryan