Recently bought Craftsman Lithium battery & charger that failed.

No way! Lithium Ion batteries require special chargers to prevent fire. They are very unstable and if they break down internally, they self combust. You can't even use a Nickel Metal Hydride battery charger with them. And it is a 19.2 volt battery, which won't charge with a 12 volt charger. Use the Craftsman charger specially made for those batteries.

https://www.walmart.com/c/kp/craftsman-volt-battery-charger

..

My Ryobi 18V One+ charger blinks green while it's charging. When the battery is fully charged, the LED goes to a solid green. However, one battery recently had a faulty cell. After several hours on the charger, the green and red LEDs both were blinking. That indicated that the battery failed late in the charging sequence. It didn't fail the initial testing by the charger. The other battery I charged that day charged fine.

The extended capacity batteries can take 12 hours to charge in my experience. The regular batteries take less time. The charge time will depend on the battery chemistry(The older NiCd batteries take longer to charge then the Lithium batteries.)

I hope this helps. Assuming you aren't dealing with a cold or hot battery or charging environment, if you have any suspicion about a faulty battery, replace it.

Cindy Wells
(Note: I have a 12V drill as well. Those batteries takes longer to charge for the same relative capacity than the 18V NiCd batteries.)

The battery is no longer any good.Here are some new ones Wanda. 156results for craftsman 20 volt battery

The Ryobi charger will flash green as it charges and then remain steady or slowly flashing green when fully charged. Flashing red means testing and if it remains steady or slowly flashing red it is defective.

No, the P110, 18V NiCad battery charger, will not charge a 18V lithium ion battery. You need one of the dual-chemistry chargers. If you have the Ryobi ONE+ batteries, you can get the P117 charger ($30) or a charger with an extra battery (P126) from a store like Home Depot. A 6 battery charger and a 12V in-car charger are also available.

I wish that I had better news for you.

Cindy Wells
(who has the Ryobi 12V drill and charger, a few of the 4V tools, and a number of the ONE+ 18V devices and chargers. The single chemistry battery charger is not used much any more.)

Lithium Ion batteries don't charge the same way ni-cads or ni-mh do. You need a lithium ion specific charger to charge them. (Some chargers do multiple types.)

I was recently told that the lithium ion does not like cold temperatures so you may need to bring the batteries and charge into a warm location and wait until they reach a warm temperature and then charge them.

Yes. But a proper charger will not do that.