Ryobi 18V Lithium Battery With Fault Ask questions and find answers to many subjects relating to electrics and electrical work

[u33446z]

A battery which was working normally a few months ago is now showing as ‘defective’ in a Ryobi Dual Chemistry charger. Pressing the battery’s charge indicator button gives a red indication. Putting a meter across the terminals gives 11 volts, and across the cell pack (after removing outer case gives 16 volts.

Anyone know what this means, other than it really is defective?

[Mr White]

You have answered your own question.

Metering just the cells on their own they have no load, so the voltage shown is just the PD. (The potential difference between two points)

[collectors]

[quote="Mr White"]You have answered your own question.

Metering just the cells on their own they have no load, so the voltage shown is just the PD. (The potential difference between two points)[/quote]

I have the Ryobi 18 volt tools & a fully charged battery should get around the 21 volts. If your getting the red light come up it usually the battery cell breaking down & not holding a charge. Must admit, i would of thought unusual with Ryobi as i have had two batteries & 6 of their tools for about 6 years & given them a lot of use with not one problem. I would be happy to buy again.