Battery in charger overnight, red light flashing, insert battery in drill, it doesnot work. Please advise. Thanking You Bob Falzano

Question edited for clarity and correct spelling of the maker.

Here is the manual section on the LED Lighting sequence. Both Red and Green flashing is not there. Your charger has a model number on the bottom of it and you didn't supply that, so this may be the wrong charger!
http://powertool.manualsonline.com/manuals/mfg/ridgid/140276002.html?p=5

The question was mentioned on Fixya before.

I have a ridgid rapid twin 18 V charger that flashes red and

Fixya https://www.fixya.com > Forum > Drills > Ridgid
Nov 21, 2019 - Red flashing means the charger or battery is to hot and must cool down before it will charge. The charger will not charge a battery if the lights are flashing.
My charger is flashing red when i place the battery in it - Fixya
Dec 7, 2010
Ridgid temp delay light flashing on charger - Fixya
Sep 2, 2019
My RIDGID Rapid Max Twin 18 volt charger, all it - Fixya
Aug 31, 2019
18v ridged rapid max charger flashes red and green same
Mar 12, 2023
More results from www.fixya.com

..

Can you try another battery to see if it is a battery problem

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

Try inserting battery quickly 5 or 6 times to see if it is just a connection problem, sometimes this works in cleaning the terminals.
press the helpful button.
I think the red blinking light is a fault, normally should be a green flashing light while charging.

I live by hitachi, one of the good things about it is lowes will exchange them as long as you have a receipt and it's under 30 days. If not chargers are not very expensive, or you can send it back for repairs. I have 10 of those combo packs and never had a problem with a single one, for you to get 2 is a freak accident.

It should tell you on the bottom on the charger what that means. But this means the battery is not taking its charge. Sorry bad battery.

For others with the same problem (flashing red light won't go off)...make sure you FIRMLY PUSH the battery down onto the charger and engage the latches. Simply resting the battery on the charger will not work.

I think your tryiong to charge NIMH batteries oon a charger designed for Lithium Ion batteries. With all the new style batteries such as NICAD, NIMH and LI-ION, charging becomes difficult. Most chargers pre NIMH and LI-ion, were designed for NICAD's. The best advise, match your batteries with the correct charger