12 volt Makita Drill Power Weak?

[Thom2]

I have a 12 volt - 3/8 Makita drill that was working great until a couple of days ago.

Now it seems to be weak and die after driving 5 or 6 - one inch drywall screws into 2x4s.

I checked both batteries. They both read between 12.37 & 12.43 volts on the meter.

Any ideas?

 

[kennyd]

Checking the voltage while not under load is a useless test on a NiCad battery, it must have a load on it.

How old are the batteries?
Do you leave them on the charger all the time?

 

[Thom2]

The batteries are 3 years old. I have left them on the charger overnight at times.
I don't know how to check the voltage when they are in the drill.

 

[Tig]

How's the weather? My cordless won't take a decent charge in my cold garage. When the weather warms up they are fine again.

Edit: Just looked and I see you are below freezing at night. Try charging them in the house.

 

[kennyd]

How's the weather? My cordless won't take a decent charge in my cold garage. When the weather warms up they are fine again.

Edit: Just looked and I see you are below freezing at night. Try charging them in the house.

Yes, good call. I never let my battery's freeze...and I never leave them on the charger after they are done.

 

[Thom2]

That's probably the problem. The drill and batteries were in my barn. Temp 8 degrees.
I've since brought them into the house and charged them. They seem stronger, but still don't have the power they had before I left them in the freezing temp.

Anything I can do?

I read a post where you could bring a battery back to life by setting up a 24 volt using two sealed 12 volt batteries, then put a lead on the neg. side and touching the pos. side for a couple of seconds.

Any thoughts?

 

[Tig]

I used to rejuvenate NiCads with a similar method. I built a container to protect myself from shrapnel in case the battery exploded, like they can.
After doing a bit of research into the toxicity of Cadmium I decided I did not want risk contaminating my shop. So I stopped.

 

[jmolwitz]

To sum it up theres nothing you can do within reason . Buy new packs . I have cells to rebuild my ryobi packs but it is way to tight to in there to handle the thickness of a solder joint , at the factory they use flat tabs that are spot welded to the cells It would be a huge uphill battle to make things fit . I have tons of experience with batteries as I have been flying electric RC planes for 10 years and have built many packs .

 

[Jw5875]

Cordless powerpacks are our new "Enemy" in the world of common sense. Why does the battery cost 85% of the tool?

Just think if you had to pay that much for your car battery -- would you throw your car away because the battery went bad!!!!

Anyhow: Been looking this route for my Makita 14.4 both sets nicad and nimh:

voltmanbatteries Home Page

Do any TBN'rs have experience with this company?

jw5875

 

[MikeD74T]

To sum it up theres nothing you can do within reason . Buy new packs . I have cells to rebuild my ryobi packs but it is way to tight to in there to handle the thickness of a solder joint , at the factory they use flat tabs that are spot welded to the cells It would be a huge uphill battle to make things fit . I have tons of experience with batteries as I have been flying electric RC planes for 10 years and have built many packs .

I replaced a bad cell in my Ryobi 18volt powerpack by breaking the strap weld & soldering in the new cell. Solder joint is only a few thousandths of an inch thick?? Actually it was one of the easier packs I've fixed because the case is bolted rather than welded. Cutting the welded pack cases is the hardest part. Two weeks ago I restored 2 of 3 DeWalt batteries for my SIL, used the third for donor cells. When he gets some new cells I'll repair that one. MikeD74T