I have a 18v Ryobi battery has fully charge but won't work in my Ryobi power tools ,I have other Ryobi battery that works in my power tools. Is any way to fix the battery?

SOURCE: ryobi 18 volt batteries wont hold a charge

Ryobi batteries are specific to each Ryobi model, so please write down which model number or the original battery part number you have. How old are the batteries?
I had the same problem with many bateries I had at home, like cell-phone batteries and also some power tool bateries. Did not have any Ryobi power tools tho, so don't hold me acountable if this doesn't apply to your hardware:)
Many batteries have the "memory effect" which means that if the battery was not completely empty when it was set to recharge it might now only recharge to the level it was emptied to, so for instance if you used the power tool for 10 mins and the battery emptied to, lets say, 90% capacity, it might occure that the next time you recharge the battery it will only charge to it's 90% maximum...doing that many times lowers the maximum recharge capacity. As I heard the new Li-Ion batteries do not have this problem.
I hope this makes some sence as my english is not that good and it was a bit hard explaining my thoughts:)

Jim London

• 257 Answers
• Posted on Feb 05, 2009

SOURCE: Ryobi 18V lithium battery won't charge

Hi, Thanks for getting back to me. The yellow and blinking red indicate a defective cell. Since it has lithium cells and is that new any repair to it would be a waste of your time. Ryobi tools purchased in 2008 have a 2 year warranty. I am guessing you probably got it at a home depot and you should return it under the warranty. All new Ryobi tools have a three year warranty. Good Luck! and Thanks for using fixya!

SOURCE: can i charge a 14v battery using a 18v charger (both are ryobi)

Absolutely not. The risk of damage to the battery is only a minor concern compared to the fire hazard you would be creating.

SOURCE: light on ryobi 18v charger

More than likely a defective battery sinse the other ones charge fine..
Bring it back for exchange of another one..

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Power Payless

• 25 Answers
• Posted on Jan 29, 2010

SOURCE: One of my Ryobi 18v battery packs (1400672) won't charge.

Use
AC / DC Power Adapter Replaces Ryobi One+ Batteryhttp://lcdpayless.com/ryobi_one_power_adapter.php