LITHIUM-ION batteries

[bubinga]

l have a 20 volt DeWalt drill, with LITHIUM-ION batteries in it.
I was drilling one night, and hit the trigger, and Bam!, Nothing.
Thought the drill went bad, switch or brushes or something.
But when I put a fresh battery in it, it was fine.
It did it again the other night.
Does this type of battery quit just like that, or are my batteries going bad.
They have not been used very much at all.
Also, when l charge a battery, I do not let it "live" on the charger, 24/7.
Once they are charged, l set them aside.
I read it was not good to leave them on the charger 24/7.
Thanks,
bubinga

 

[uncletater]

that is normal with Lithium. The dont slow they just "bam" stop. Normally when you have the screw about 3/4 the way in.

 

[dnschmidt]

That's the way lithium ion batteries die. You have full power until they stop dead. There is no drop off of performance as is the case with NiCd or Nickel Metal Hydride. Many Li Batteries, mine are made by Milwaukee, have "gas gauges" on them so that you can tell how much charge is left. My guess is that your batteries are fine.

 

[stikman56]

l have a 20 volt DeWalt drill, with LITHIUM-ION batteries in it.
I was drilling one night, and hit the trigger, and Bam!, Nothing.
Thought the drill went bad, switch or brushes or something.
But when I put a fresh battery in it, it was fine.
It did it again the other night.
Does this type of battery quit just like that, or are my batteries going bad.
They have not been used very much at all.
Also, when l charge a battery, I do not let it "live" on the charger, 24/7.
Once they are charged, l set them aside.
I read it was not good to leave them on the charger 24/7.
Thanks,
bubinga

Yes,they can and will. They have electronics in them because they cannot be fully discharged or they will never charge again. Snap-On had BIG problems with their CTB6185 batteries doing what you described. They superseded them with the CTB6187 because of it. These would come on, go off, come on again etc. if you just kept the trigger pulled. Have you tried keeping the trigger pulled for about a minute and see what happens?

 

[GSteg]

Lithium-ion batteries have a flatter discharge curve than Nicad, but it's still predictable as to when it'll give out. It doesn't go full power and then stop. It tapers off slightly and you can tell when it's getting weak.

 

[bubinga]

that is normal with Lithium. The dont slow they just "bam" stop. Normally when you have the screw about 3/4 the way in.

That's the way lithium ion batteries die. You have full power until they stop dead. There is no drop off of performance as is the case with NiCd or Nickel Metal Hydride. Many Li Batteries, mine are made by Milwaukee, have "gas gauges" on them so that you can tell how much charge is left. My guess is that your batteries are fine.

Lithium-ion batteries have a flatter discharge curve than Nicad, but it's still predictable as to when it'll give out. It doesn't go full power and then stop. It tapers off slightly and you can tell when it's getting weak.

OK, good to know it is normal, this is the first time I had these kind of batteries.
Thank You........................

Yes,they can and will. They have electronics in them because they cannot be fully discharged or they will never charge again. Snap-On had BIG problems with their CTB6185 batteries doing what you described. They superseded them with the CTB6187 because of it. These would come on, go off, come on again etc. if you just kept the trigger pulled. Have you tried keeping the trigger pulled for about a minute and see what happens?

No, l have not tried that, I will..................

 

[Loscaldazar]

Lithium-ion batteries have a flatter discharge curve than Nicad, but it's still predictable as to when it'll give out. It doesn't go full power and then stop. It tapers off slightly and you can tell when it's getting weak.

This.

Also, if your model is brushless dewalt, brushless motors only increase the effect. You'll be drilling, then instantly it will shut off.

 

[tarbellb]

Personally I like it. There is a slight change in power then instantly off. It keeps me from doing the classic "one more screw (x10) at 30% power THEN I will change the battery" procedure so common with NiCad.

 

[Stuey]

Yep, sounds normal. There's usually a low voltage shut off circuit to prevent over-discharging, which as someone said can damage the battery cells.

 

[bubinga]

This.

Also, if your model is brushless dewalt, brushless motors only increase the effect. You'll be drilling, then instantly it will shut off.

Don't know if it's the brushless dewalt drill or not?

 

[DennisH2014]

This is the reason, excellent explanation Stuey! Battery tech is surprisingly unknown to many people, especially when it comes to power tools!

 

[sac02]

Yep, sounds normal. There's usually a low voltage shut off circuit to prevent over-discharging, which as someone said can damage the battery cells.

Yup, this is the answer. Protection circuit in action. Overcharging, over-discharging, and especially recharging-after-over-discharging is dangerous with Li-Ion chemistries.

Nicad and NiMH could just be run down until flat dead and recharged - deep discharging like that wasn't good for the battery lifetime durability, but it wasn't a safety issue like it is with Li-Ion.

 

[bubinga]

So Nicad and NiMH should be charged at the 1st sigh of discharge?

 

[ricepudding]

so nicad and nimh should be charged at the 1st sigh of discharge?

all batteries should be charged at first sign of discharge,

I am currently making a guide to li-ion batteries, hint hint nuge nuge Check it out

http://www.garagejournal.com/forum/showthread.php?t=265440