The Stovebolt Site Forums The Shop Area The Tool Chest I just did something monumental

I tried a trick I learned on a 18V drill battery that would not charge. I thru it away and then I got it out of garbage. Somehow the circuit board inside Ryobi battery has a failure and when battery gets too low, it won't allow charging. If you have a cordless battery that will no longer take a charge, this may work. It did for me. Remedy: Take battery apart, 4+1 screws, pull out the whole assembly from the base. Observe rechargeable batteries in series.(5 of them in my case). Take a baseline voltage reading of each battery (probably 1V each). Take a baseline reading across the entire pack (maybe 5V) Take a baseline reading at the master contacts on nose of pack. (might be zero) Weird right? Use your voltmeter to determine pos and neg of top battery to bottom battery. (not the main nose/tower contacts) Wear safety shield, use your automotive 12V battery charger. Touch pos to pos and neg to neg for 15-20 seconds. You are touching so that the entire battery pack is being charged. (both ends of the series). After 15-20 seconds, NOT MINUTES, you will get a reading, maybe 10-11 volts. If you get that you are in fat city. Put back together and use the dedicated charger. It's like after the internal batteries get a certain charge level, the PC board will allow charging.

Warning: My 18V battery had Torx security screws. Bastards! That tells me they know a person can fix it!
If the heads were bigger I could have drilled a hole in the end of my Torx bit. They make Torx security drivers. But guess what? I had to use a die grinder, CAREFULLY, to cut thru plastic and cut off 4 screw heads. Left the one in the middle of the power nose. Came within <1/8 inch of cutting circuit board! Had to pry out the pack past the lock tabs. My battery looks like it exploded. It was worth the effort (30 minutes to save a bunch of money on these batteries.)

I will post if battery "locks up" again after use. I don't think you can do this by touching automotive charger to the power tower contacts which go thru the PC board to the cell batteries. You must bypass the circuit board. DON'T get the polarization wrong when charging!!!
I'll let you know if anything bad happens. I have to electrical tape it back together.
It seems like the actual smaller batteries inside are not failing, but the circuit board is. This is said to be much easier to do on other brands.

Very cool! Might have to send that in as a question to a Canadian YouTube guy that enjoys tearing stuff apart and seeing how it works. He might be very interested in your method! Look him up if you get a chance, but be aware that he's not always kid friendly with the language. Search for AvE and you should be able to find him.

Use a Dremel cutoff wheel and turn those TORX screw heads into slots. Then you won't have to "Norwegian-Rig" it back together!
Jerry

Didn't have Dremel and the darn screws are recessed in a plastic counterbore. I read where you can use the safety pin as an advantage. It helps you to wedge a flat blade screw driver in there and turn the Torx screw. Didn't read that in time. Anyway it charged up.

I have tinnitus, but I can still hear birds.
"Cheap"
"Cheap"
"Cheap"
The tell was, "Ryobi".
The Yugo of the cordless tool world.
I'm sorry. I have been PM-ing HRL too much tonight.
Good find bartamos!
If you have a battery pack which doesn't have a circuit board in it, you can give them a goose by momentarily touching the contacts with a jumper wire from a higher voltage battery pack. You only need to touch them long enough to make a spark. The factory charger has a circuit board which won't allow a charge on a weak battery pack, but once you give them a jolt, the charger will kick in.
Carl

Not going to ask what one is best because this will turn into a Democrat/Republican, Ford/Chevy, Elvis/Michael Jackson, Rebel/Yankee, Green Bay/Vikings 100 round fight without ring girls.

My Ryobi batteries must be pretty old. The screws were Phillips head.
I did not see a circuit board.
The only reading I could get was 1.1V.
I held my battery charger on the terminals for the 20 seconds. Voltage increased to about 8V. Put it back together and then into the charger. The yellow and green charger lights stayed on for over 2 hours. I tested the battery in a flashlight and it was "kinda" bright. I remember it as brighter with a normal battery.
Time will tell. I have several more to test as well.

My test was on 18V ONE + Ryobi brand batteries. Each small battery wants about 3.6V for an 18V. What is the voltage of your tool? What is the normal charge time?

You got that right brother!
It probably is Ryobi (my prior undisciplined HRL-induced rant not withstanding).
Carl

I just remembered something else to try with these weak batteries/stupid chargers.
If the battery is just weak and not dead, but will not hold a charge very long, you can leave it in the on position until it is completely dead, then give it a jolt from a higher voltage source and put it in the charger.