Battery is not charging and don't know if charger is at fault or batteries need to be replaced. Drill is 8 years old.

If it is 15 years old the batteries will need replacing. They were the worst of all the battery types and were replaced by Nickel Metal Hydride and now Lithium. NiCad batteries suffer with 'Memory Effect' and also lost power in storage. Find the YouTube channel of 'Big Clive', he just did a video on battery types, pros and cons.

https://www.youtube.com/c/Bigclive

IIRC, two terminals are the charging plus and minus and the other two are for the charger diagnostics.

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It is likely the fault is the battery and not the charger. To confirm this take the charger to any Radio Shack and ask them to test the charger or if you have a small meter do it yourself, the charging voltage will be up to 5 volts more than the rated battery voltage of the drill, so if you get a high reading don't worry about it. Fast charger will be way over the battery rating, also fast chargers have a cost, they shorten battery life due to heat. I have had many battery powered tools, I have found that the batteries last about 2 years on average. I have this same Dewalt drill driver.

Really --- come on now

Your luckly they lasted 3 years

I'am not an engineer that can do a forensic
examine on your dead battery. So i don't know

If it is that old, the batteries are probably nimh (nickel metal hydride), not lithium, but either way, they will not be any good after sitting that long unused. Nimh have to be charged every couple of weeks due to self discharge, and lithium need to be charged every couple of months, but once a month is better. This is true if you use the drill or not, you have to take care of the batteries. They will have to be rebuilt or replaced. Oh, also make sure you are using the correct charger because if you use the wrong one, the batteries could catch fire and damage your home/garage/shop. Never leave a charger in use unattended. (Do not try to charge batteries and go to bed, very dangerous!) Good luck

If light is on charger the charge is fine. You could verify using voltmeter it should put out = to what it says on the back of charger 12-18 volts or so.
Most likely battery is shot after 8 years they just dont' hold a charge anymore and they often will only charge for a few minutes when the chip in the computer tells the charger to shut off due to defective battery.
compare prices of new drills and new batterys sometimes new drill is not much more. Try ebay and harbor freight for ultra low priced batteries.

Don,t worry about lights,just check if the batteries get charge.If not your charger is fry.Is time to buy a new one.

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$8 - 8 stores Bosch 72068 3 hr.cordless Drill Charger
$20 - 2 stores 18 Volt Drill Charger (60109004)
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After 8 years its possible you have some corrosion or bad contact on drill, takeing it apart an checking inside may be to much for you,but make sure all contact are clean on outside.

have you tried the batterys in any other tool?

you would also need to check the voltage of the batterys they should be at least 18 volts (19 prefered)

then if the batterys do not show charged you would need to make sure the battery charger is putting out voltage.

After that contact your closest Ryobi service center we would check that for free to let you know what you need, I am sure you local place would do the same.

How old is the battery?
They have a service life and require replacing after they no longer hold a charge. This could be 2 years or 8 years depending on how often it is used and how regularly it is charged etc.

If it is a new battery, then take it back as it could be defective.

Possibly could also be the charger but you could verify that by charging a different battery and seeing if it charges that second battery ok, or not.

How old is the battery? They do die if old and well used! You can try checking the fuse inside the charging unit . If this does not work or fuse is OK you can get the battery revived (there are places that do this) if it is not completely stuffed or just get a new battery which are quite cheep on ebay