Battery charger Ryobi p118 stays red all the time & it is only 3 months old

SOURCE: ryobi battery charger

The same thing happend to my charger, i let it cool down and now the green light goes off and shows red again. thanx for that post

SOURCE: NEED A MANUAL FOR A RYOBI BATTERY CHARGER

This link should help in finding a manual. Good luck. http://powertool.manualsonline.com/manuals/mfg/ryobi/ryobi_battery_charger_product_list.html

SOURCE: Can I leave my Ryobi P113 charger with a P103

Yes you can that is an automatic charger when it is fully charged it shuts down the charging portion but keeps the charged light lit however this does not effect the battery.

SOURCE: The Yellow and Green light both come on and stay

http://oneworld1.inetu.net/manuals/ryobi/hp1442m_1802m_874_eng.pdf
It sounds like your battery is bad. If yellow and green are on for more than 15 minutes it probably a defective battery pack. See page 8 in the manual.

SOURCE: Ryobi p111 charger -- light stays red

My charger do the same thing. I talked with the service people at Ryobi who said that the red led never goes out no matter how long you charge it. They suggested just charge it for 12 hours and then disconnect. Pretty dumb system, but that's apparently the way it is.