Ryobi 1 Plus Battery - Dead Battery or dodgy charger

Mart7379

Hi guys, 

Eventually got round to buying a charger for the Ryobi one Hand vac that has been sat on a shelf since it was bought a good few months ago.
 

Anyway, after plugging the battery in, the red light flashes for a few seconds then it turns green, thus indicating the battery is fully charged according to the instructions (I can assure you the battery is completely dead). 
 

I have connected the battery to a multimeter and this only shows 6v (the battery is 18v) so following a little research on Google I come across something that states if the battery is fully discharged it can enter a sleep mode and needs ‘mini charges’ to recover. Is this true or am I likely to just waste my time in attempting it? (It states ‘plug battery in for 2-3 seconds then remove and repeat to recover from sleep mode, it can take upto 30 mins’ 

 

https://applianceanalysts.com/fix-ryobi-battery/

George_Michael

As you've rightly said, if the battery voltage goes too low the charger thinks it's dead and won't pump any current into it.
As it's 18v, there is one thing that you can try that often works.
Get a couple of 9v PP3 batteries and wire them up in series:

then connect this up to your Ryobi battery (positive to positive and neg to neg) and leave it there for about 30 seconds. 
Keep an eye on it as the PP3's can get quite warm when doing this and when you've disconnected it, plug it straight into the charger.

This often brings the voltage of dead battery up high enough so that when it gets plugged into the charger, it will accept it.
If it doesn't work the first time, try leaving it connected up to the PP3's a bit longer.

Mart7379

Smashing, I will pick up some 9v batteries over the weekend and give it a try. I have a Black & Decker 18v battery, would wiring this to the + and - of the ryobi battery give it w little bit of juice ? Or is it best with a couple of 9v 

Belenus

Your B&D battery would probably be better as it is less likely to overheat.

It will probably deliver a bigger punch so take care and watch out for overheating or any swelling or leaking in either battery or whatever wires you use.

Wear gloves and protective eyewear or face wear just in case something goes bang.

Don't blame me if all that is bad advice, I'm no expert on such things.

Mart7379

I’m currently attempting it, the only wiring I had was an old power cable so stripped it down and currently have it wired from my B&D to the ryobi 

fingers crossed it is enough and recovers it. Multimeter shows there’s 18.9v running through the cable so there’s a current going into the ryobi 

Mart7379

Had the 2 batteries wired up to each other, + to + and - to - for about 5 mins, tested with the multimeter and still showing 6v so going to give it a little longer, keeping a close eye on both batteries. 

The battery that is discharged has been plugged into a Hand vac, and sat on a shelf for at least 12 month. So guessing the battery will be severely discharged. Maybe not even recoverable. 

Mart7379

I think it’s safe to say the battery is goosed. Had it wired up initially for a good 5 mins, no improvement on the volt reading, 2nd time I had it wired up for about 10 mins and still showing 6v, battery is stone cold, even after being wired up for upto 15 mins. (I checked the voltage of the ryobi battery whilst wired up and it was reading 18.77v once wires were disconnected it returned to 6v