TDK 15.6 battery life

[scotthz@yahoo.com]

Hi,
I have a TDK 15.6 drill that I bought about 15 months ago. I'm an amateur woodworker and builder, and use the drill mostly on the weekends. When I'm not using the drill, the batteries lose their charge very quickly, within just a day or two after charging. After putting a freshly charged battery in the drill, it works great. I drive a few screws or drill a couple holes, and put the drill down again. It is still almost fully charged. When I pick it up again one or two days later, the charge is almost gone and I have to switch batteries.

When I use it more heavily, I get an acceptable amount of usage from a single battery before I need to recharge. But when I use it lighly, it drains very quickly on the shelf. I expect some drainage from NiCD batteries, but 70-80% per day seems bad. So I almost never have two freshly-charged batteries. I have to charge the one that drained on the shelf before I can use it. I never charge the batteries until the drill starts to slow down in use. So I don't think this is the NiCD "memory effect".

Is this normal behavior for this product, or do I possibly have a bad charger and/or batteries?

Thanks, and best regards,
Scott Herzinger

 

[greg mann]

Do the batteries drain if they are not on the drill? If not, then there is a drain through the switch and it is the drill not the batteries. Check that out first.

Greg

 

[bigbadpig]

Aside from what Greg pointed out .... I think that NiCd (and to a lesser extent NiMh) will always leak charge over time and repeated charges.  For a hobbyist like myself, who doesn't pick up a drill every day,  I find that with most of my cordless tools I need to  wait charge the batteries before using them.

This is one of the reason why Lithium batteries are so attractive to me, they can hold their charge for months.  I actually don't care as much about power or number of Amp hours they can hold.

 

[Dave Ronyak]

I cannot speak with reference to Festool's batteries, but I have no shelf storage problems with my 2.6 AH NiMH batteries that came with the Makita drill I purchased about 4 years ago.  Both are still going strong, and hold much of their charge even when laid up for a couple of months.  I do not need to recharge them before putting them back into use for small jobs.  IMO Festool should move to Lithium Ion batteries to gain the benefits of even less weight, longer life (# of recharges) and essentially zero loss during storage.  A premium price for a premium product should include premium technology.

 

[Christian93117]

"A premium price for a premium product should include premium technology".

Yes, you are right. And we want to make sure the technology is a premium technology
down the road. The speed of innovation on Lithium Ion batteries for power tools has been so high, that
a new battery was not the latest technology anymore shortly after it was available in the store.
We feel now that we can offer something that is the premium battery technology not just for
a couple of months, but for a longer time. We don't want to offer something just because everybody
is offering it and because it is the latest technology. We want to offer it once it has a true, longterm
benefit for our customers.

I might sound like a marketing brochure, but I just wanted to offer some insight on why Festool
didn't jump on the Li-Ion bandwagon right away.

Christian

P.S. Scott, I will get back to you regarding your question.

 

[stevea]

Scott,

I had a problem with my CDD 12 batteries which turned out to be the charger. I shipped the whole thing to Festool here in Australia and they fixed the charger, and checked the batteries (providing load/run graphs which showed the charger hadn't damaged the batteries). I guess I'm saying the charger may not be working 100% and that could be the problem, not the batteries.

-steve

 

[JayStPeter]

I've noticed the same thing with my 12V TDK.  There's always a fresh one sitting in the charger, so not a big deal.  But, can be an annoyance at times.

 

[bill-e]

I gotta believe it's a bad battery or a bad charger.  My 12 and 15.6v batteries seem to last forever, even when I use then only occasionally.  I've never picked up either drill to find I had to recharge it.

Now I did have a thermal protector in the battery go bad.

 

[ccmviking]

Doesn't sound right that's for sure.  I use both the Nicad and Nimh in my C12 Drills and their performance is very good.  I would think that it has to have something to do with Parasitic drain.  It's charging good if you can use it for extended use during a single day, and it would be rather strange to have 2 batteries exhibiting the same problem.  I would definately try as someone suggested to leave that battery fully charged and out of the drill or charger for a day or two, pop it back in the drill and check it out.  You can also take a couple of voltage readings at certain intervals to see if you can spot a change (not too likely the way they discharge their power over time).

Chris...

 

[jrtibbetts]

Like you, I'm a novice woodworker. I have the C12 & the TDK15.6, and they keep their charges without any problems. Just last week I used the C12 for the first time in a couple of months, and it was ready to go.

 

[Christian93117]

Scott,

I did some research, and got an answer from the R&D department in Germany. They are assuming
that the battery pack is faulty. Since the batteries are working good right after you have charged them,
the charger doesn't seem to be the problem. Also the switch or the drill itself don't seem to be the
problem as the drill works when you use it heavily. It is very likely that 2-3 cells in the battery pack
are faulty. These cells don't charge fully anymore and discharge quickly.

Could you please send me an email and I will make sure that you will get new batteries.

Regards,

Christian

 

[John Langevin]

I have the same problem with my 1 1/2 year old TDK12. I leave one battery in the drill and one in the charger. I don't change batteries until the one in the drill is fully discharged. When I change to the charged battery I don't feel that I am getting good battery life out of it. My old DeWalt 12V would drive significantly more screws. But since I sold the DeWalt the TDK is the only cordless drill I have and I am reluctant to send the whole thing back and do without for an indefinite period of time. What might I expect for turnaround time? Are there any tests I can perform with a multimeter that could confirm where the problem is so that I could just request the correct part or parts from Festool without returning the drill?
colonelhogan@verizon.net

 

[JayStPeter]

Then I have 2 bad battery packs??? ???

Here's how it works for me.  I'll put a battery pack in the drill and drive 2 or 3 screws (or some other minimal usage).  Then I'll come back the next day and start drilling 1/2" holes in oak (or some other hard use).  After 2 holes the battery that I drove 2 screws with yesterday is dead.  I put the fresh battery in and drill 10 more holes and drive 15 screws and it never dies.  It is a given that if I haven't put the battery in from the charger that day, it is only going to be good for a small amount of work.  I guess I need to mark the batteries to make sure, but I think they are both the same way.  I'll put a piece of tape on one of them tonight just to be sure.

Maybe they are bad since I've never been impressed with how long they last compared to my old PC 12V.  But, with the other pack ready in 15 minutes I've never been lacking another to plug in (though I'm sure I've come close).  With the PC, I could easily kill a pack before the other was done.

 

[greg mann]

I still think a needed test is to take the battery off the drill when not in use to see if it discharges off the drill. Unless you do this you don't know as much as you can know. There are THREE elements to this puzzle. The battery, the charger, and the drill. If you don't test all the iterations you don't have all the info. So far, I don't think I have read that anyone with problems has them unless they leave the battery on the drill for some period of time, like overnight. I suggest the following: Charge the battery, drive 10 screws to make sure it has a decent charge, take it off the drill, leave it for tomorrow, drive ten more, take it off, etc. See how long it lasts this way. If it seems pretty good this way then I would suspect a drain through the drill when at rest is the culprit.

 

[scotthz@yahoo.com]

I wanted to acknowledge the attention and customer service that Christian has provided regarding my problem. I really appreciate his response and follow-through.

Regards to all,

Scott

 

[greg mann]

I wanted to acknowledge the attention and customer service that Christian has provided regarding my problem. I really appreciate his response and follow-through.

Regards to all,

Scott

Scott,

Does this mean you/Festool have figured out your problem? What have you learned?

Greg

 

[bill-e]

I wanted to acknowledge the attention and customer service that Christian has provided regarding my problem. I really appreciate his response and follow-through.

Regards to all,

Scott

Scott,

Does this mean you/Festool have figured out your problem? What have you learned?

Greg

I'm interested also.  It's funny but I just posted on WoodNet that my TDK batteries seem to last forever.

I guess YMMV really means just that

 

[Christian93117]

Bill, Greg,

Here is my answer posted on February 7th:

------------
I did some research, and got an answer from the R&D department in Germany. They are assuming
that the battery pack is faulty. Since the batteries are working good right after you have charged them,
the charger doesn't seem to be the problem. Also the switch or the drill itself don't seem to be the
problem as the drill works when you use it heavily. It is very likely that 2-3 cells in the battery pack
are faulty. These cells don't charge fully anymore and discharge quickly.
------------

Scott's old batteries didn't come in yet. Once they are here, we will do some testing. Scott got his
new batteries and it will take a while to find out if they solve the problem.

I will post the findings once we have done the battery test.

Regards,

Christian

 

[bill-e]

Thanks Christian.

How many other company CEO's also do customer service?

 

[scotthz@yahoo.com]

Haven't had much time to check in on this thread lately...

So far, the batteries are holding up fine. I've used the drill a few hours over the last couple weekends, and the charge has been fine. I've only had to swap batteries through the charger twice since the initial charging. And that was after normal usage, i.e. using the drill for drilling and driving a number of fasteners. The batteries haven't lost charge just by sitting in the drill for a couple days. I assume that my old batteries have made it back to Festool, and it will be interesting to know how they test out.

Scott