DIYbanter - View Single Post - 2 Dead Cordless Drill Batteries -- Weird

Xeno

On 25/5/20 6:05 am, wrote:
On Sunday, May 24, 2020 at 3:46:33 PM UTC-4, Ed Pawlowski wrote:
On 5/24/2020 3:29 PM,
Anyone have any insight here? I have two Makita cordless drill batteries that I use infrequently. Stuck them in the charger, which lit up red, then after a while green -- like usual -- but neither battery would operate either my drill or my flashlight (i.e. appears they have no power). But the charger recognizes them, lights up red and then green, so this is not the usual situation where they don't have enough charge to trigger the charger. Any thoughts? Weird that it's both. Maybe the charger is busted somehow, even though it appears to be operating as usual?

How old are the batteries? If more than a few years either toss or
rebuild them. Yes, both will dies around the same time period
especially if sitting for long periods of time.

Yeah, but what's weird is that everyone else whose batteries die, they say that the charger doesn't recognize them. It flashes an error, or whatever. My charger seems perfectly happy to receive these batteries, which I assume means they've got some power left in them. It even thinks its charged them -- the light changes from red to green. So that's what makes me wonder if it's maybe not the batteries after all. I guess I need a multimeter to check the power?

I think you will find the charger is seeing a high resistance in the
batteries and it thinks they are charged.

With those batteries, self discharge is an issue. You should drag them
out at least every three months and top them up if they have long
periods of disuse.

There may be a way to get charge into them but you will probably find it
isn't worthwhile.

--

Xeno

Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)