Ryobi p125 multiple charger not charging

the trimmers switch may be faulty.

CHARGING THE BATTERY PACK
Battery packs for this tool are shipped in a low charge condition
to prevent possible problems. Therefore, you should
charge them until the green LED on the front of the charger
comes on.
NOTE: Batteries will not reach full charge the first time they
are charged. Allow several cycles (operation followed by
recharging) for them to become fully charged.
CHARGING A COOL BATTERY PACK
See Figure 3.
If battery pack is within normal temperature range, the red
LED on charger will come on.
NOTE: If the charger does not charge the battery pack
under normal circumstances, return both the battery pack and
charger to your nearest Ryobi Authorized Service Center for
electrical check.
n Charge the battery pack only with the charger provided.
n Make sure the power supply is normal household
voltage, 120 volts, 60 Hz, AC only.
n Connect the charger to the power supply.
n Place the battery pack in the charger aligning raised rib
on the battery pack with the groove in the charger.
n Press down on the battery pack to be sure contacts on
the battery pack engage properly with contacts in the
charger.
n Normally the red LED on charger will come on. This
indicates the charger is in fast charging mode.
n Red LED should remain on for approximately 1 hour
then the green LED will come on. Green LED on
indicates battery pack is fully charged and charger is
in maintenance charge mode.
NOTE: The green LED will remain on until the
battery pack is removed from the charger or charger is
disconnected from the power supply.
n If both yellow and green LEDs come on, this indicates
a deeply discharged or defective battery pack.
Allow the battery pack to remain in the charger for 15
to 30 minutes. When the battery pack reaches normal
voltage range, the red LED should come on. If the
red LED does not come on after 30 minutes, this may
indicate a defective battery pack and should be
replaced.
n After normal usage, a minimum of 1 hour of charging time
is required to fully recharge battery pack.
n The battery pack will become slightly warm to the
touch while charging. This is normal and does not
indicate a problem.
n Do not place the charger and battery pack in an area of
extreme heat or cold. They will work best at normal room
temperature.
NOTE: The charger and battery pack should be placed
in a location where the temperature is more than 50°F
but less than 100°F.
n When batteries become fully charged, unplug the
charger from power supply and remove the battery
pack.
Source(s):http://toolboyworld.com/eBay/Ryobi_P110/...

When the battery is charged the green will be steady on and the red will go off. Flashing green is an indication that it is charging.

hope this helps?

If it is charging the battery properly I would not worry about it. Just do not leave it connected all the time. Charge the battery and disconnect.

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.

Mike, Would need a bit more detail to give the best answer, but here are some general tips to point you in the right direction. Need to know if you get any LEDs on the charger or batteries, do you have other batteries you can use to test the charger/tool to isolate the problem (even the old NiCads)? Does this problem occur with one or both new batteries? Anyway, read below for some suggestions:

Lithium Ion batteries do not like to be fully discharged even if they are new. If you ran a tool until the battery fails, two problems can occur. 1. The circuitry in the charger and the battery itself senses a fault due to "too low" voltage in the cells, and prevents charging as a protection measure (prevents overheating a shorted cell). 2. You damaged the cell(s) inside the battery either due to sulfate build up or heat. If your Ryobi charger is flashing a red LED (no green) indicating battery fault,

I have found that removing the battery and reinserting it multiple times can help as the charger does a diagnostic when you first insert the battery. This test likely applies a small charge to the cells and analyzes the response, if you do the test enough, it can bring the cells back up to a sufficient level to allow the charger to accept it.

If the battery charger cycles normally but displays a full charge very quickly, the battery may be defective and not pulling any current from the charger, so the charger thinks it's fully charged.

If the battery charger does not sense the battery at all (no LED display) then the problem could be a defective charger, defective (open) battery or corroded/dirty connections (make sure no paint or dirt got into the charger port and no rust on the contacts).

If only the red light is flashing then the battery is not charging at all. Ryobi identifies in the manual that batteries will not charge below 43 degress F. If your batteries and charger are in the garage in a cold climate, warm the batteries to room temp in the house and then try again. If the charge starts when the batteries are warm they will continue charging for the full cycle even in a cold area.

Lithium-Ion batteries require careful charging and temperature monitoring while in the charger. Ryobi's Charging station monitors many functions and shuts off when the battery has gone through a complete charge. This is indicated by a steady Green light. Once the Charge indicator is a steady green the charger stops charging. With any battery It will slowly discharge and I don’t think the Ryobi will maintain a battery that is never removed. For example, if after a complete charge cycle if the battery was left there for 2 years and then you went to use it, it would likely be completely discharged. However if the battery charger is unplugged then plugged back in a new charge sequence would start. I lose power at my house about every 6 months or so. Once power is restored a new cycle would start and the charging cycle begins again.
Hope this helps and have a great day.

Here is the manual:
http://toolboyworld.com/eBay/Ryobi_P120/P120_566_eng.pdf

Red = quick charge
yellow = evaluating
green = charged

CHARGING A COOL BATTERY PACK
If battery pack is within normal temperature range, the red LED on charger will come on.

Red LED should remain on for approximately 1 hour then the green LED will come on. Green LED on indicates battery pack is fully charged and charger is in maintenance charge mode.

If you are sure your charger is working properly then your one battery may be shot.. i even had a new battery quit charging and had to replace it. they do not come cheap.

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!