Do you leave your batteries in your tools? I'm a field technician and I have noticed that when I leave my batteries in my DCF961, the batteries die in short order. The Milwaukee 12V tools I use and treat the same way don't have the same problem. I have the DeWalt DCS438B but I don't leave the battery in it to keep from possibly damaging something. Is it just a DeWalt thing or should I do more testing to see if it's a tool or battery problem?
Question for DeWalt 20V cordless tool owners
- Thread starter Outlier
- Start date
WWheeler
Well-known member
My batteries are almost always either in a tool or on a charger. I've never had issues with them dying not in use. I often pick up a tool w/ battery I haven't touched in a month or more and still have a full set of lights.
Herzog
Member
I have a few dewalt tools that I constantly leave batteries in. My small impact, drill and medium impact. None of them drain the battery. However, a couple other tools do drain them somehow. One of them is a grinder. I can't recall which other tool drains them.
I would almost suggest doing some testing to confirm that you are actually experiencing some parasitic drain. With batteries as large as powertool batteries, a few micro amps of parasitic drain is going to be slower than the self discharge rate of the batteries. I would think it would be almost unnoticeable.
I think your kids are sneaking in your shop using your tools while you're sleeping...
That's why I thought it odd. I've been driving around with the charged batteries in all of my cordless tools and the DeWalt 961 has been the only tool killing it's battery. I mentioned the cut-off tool because I don't leave the battery in it so I didn't know if it was a DeWalt thing. My Milwaukee and Makita cordless tools don't do this.
I leave batteries on all of my Dewalt and Milwaukee power tools, I've not experienced any issues with the batteries being drained just from sitting in the tool. Is it possible that your 961 is somehow being activated while driving around? I keep a lot of tools in the back seat area of my work truck, occasionally one will start up when I go around a corner or hit a bump in the road. I do not own a DCF961, does that have that "Tool Connect" Bluetooth thingamajig?
I’ve never had that issue with my DeWalt tools either. Most of the time, I leave my batteries in the tools without problems. Could be that your 961 is somehow getting activated during transit, like someone else mentioned. Have you checked if it has a Bluetooth feature like the “Tool Connect” system? If that’s activated, it could be draining the battery without you even knowing it.
I don't leave the batteries in mine, so they don't seem to drain. I don't know the model of the 20V drills I have offhand, but they shut off after 5 minutes of running. There is a timer built into the circuitry that does this, and it makes sense to prevent accidental discharge by a contractor that has them in a bag/box in the back of their truck with a bunch of other ****. The reason I noticed this is that I run in a new ratchet on the drill at a low speed, I use a large twist tie on the trigger and then go do something else, and noticed that it automatically shuts off. I thought that the twist tie loosened, but it happened multiple times, so I timed it and it's right at 5 minutes, every time.
Ego batteries will self-discharge if they aren't used for 30? days- supposedly to prolong life. For me, this means that the first time I need to use the blower after 4+ weeks sitting, the battery is almost dead. Annoying, but I guess they know what they're doing.
Ego batteries will self-discharge if they aren't used for 30? days- supposedly to prolong life. For me, this means that the first time I need to use the blower after 4+ weeks sitting, the battery is almost dead. Annoying, but I guess they know what they're doing.
mike93lx
ALLIANCE MEMBER
I always have a battery my dewalt drills and impacts. Can't say I've ever noticed an issue.
Farmall450
Well-known member
Yeah, some of the tools in the basement I'll let sit on a battery for a year or better with no issue. All mine in the shop "stand up" on the toolbox, so they all have a battery in them. No aggressive drains noticed here. I do know the 20v to 18v stem adapter will drain them in short order (and the instructions say not to leave the battery attached).
SwissMetric
Well-known member
With Bosch ProCore batteries I can unlock the battery and slighly pull it back without removing it, doing so the batttery is no longer electrically connected but doesn't fall off. I'm not sure if it applies to all ProCore cordless tools though.
As I'm a sissi I always remove the battery (or power cord) to replace blades.
I don't let corded handheld power tools plugged but usually I don't remove batteries, can't remember issues.
Can try to measure some stand-by currents but it requires a bit of cabling improvisation.
As there is a hand switch there is no reason to draw any noticeable stand-by power excepted maybe for some theft protection.
I don't remember exactly details of the DeWalt batteries, I only rarely use them.
I'd pay attention to keep both male and female contacts clean and never let them visibly corrode.
As I'm a sissi I always remove the battery (or power cord) to replace blades.
I don't let corded handheld power tools plugged but usually I don't remove batteries, can't remember issues.
Can try to measure some stand-by currents but it requires a bit of cabling improvisation.
As there is a hand switch there is no reason to draw any noticeable stand-by power excepted maybe for some theft protection.
I don't remember exactly details of the DeWalt batteries, I only rarely use them.
I'd pay attention to keep both male and female contacts clean and never let them visibly corrode.
dnschmidt
Well-known member
Call DeWalt tell them the problem described and file a warrantee claim. Why screw with this issue yourself.
That's why I posted the thread. I wanted to make sure and it doesn't appear to be normal so I will do just that.
@Outlier
I've been using DW20v for quite a few years now and have never experienced battery drain. New tools as well as old tools. I don't have the 961 but I have the 900. No issues with that impact.
I will say this, my neighbor bought a DW tool and it'd drain the battery within a couple of days. He sent it out for warranty and they came back and told him it was a knock off tool. They said knock-off batteries and knock-off tools don't always have the same battery management system as the real DW tools.
I've been using DW20v for quite a few years now and have never experienced battery drain. New tools as well as old tools. I don't have the 961 but I have the 900. No issues with that impact.
I will say this, my neighbor bought a DW tool and it'd drain the battery within a couple of days. He sent it out for warranty and they came back and told him it was a knock off tool. They said knock-off batteries and knock-off tools don't always have the same battery management system as the real DW tools.
That would be a bit of an issue. I am familiar with the counterfeit issues so made sure to buy from an authorized distributor. Acme Tools in this case.
GirlnAgarage
Well-known member
Yes for the drill and driver using the 1.5a batteries. No for the big battery tools tools like pole saw, grinder and the big impacts using the 4ah +. Never run into a run time issue. I heard about batteries losing charge or trickling out, IDK if that's true but I make connections with the b ig batteries/tools when they are being used on a job.
fourjeepin
Well-known member
I have mostly Ridgid 18v, but have noticed this issue with my Ryobi finish nailer.
swsman
Well-known member
Typically not, have not noticed discharge issues when I did.
In the winter I store all batteries in the basement, garage is unheated.
So far so good...
In the winter I store all batteries in the basement, garage is unheated.
So far so good...
johnre
Well-known member
I always leave one on the leaf blower, and the other on the charger. This arrangement assures that the blower is always ready to go, and a spare battery is at hand.
Other tools were bare tool purchases, not used as much, and get a battery only when needed. Then they are put away bare.
Never had parasitic drawdown issues that I know of.
Other tools were bare tool purchases, not used as much, and get a battery only when needed. Then they are put away bare.
Never had parasitic drawdown issues that I know of.
This is not being a sissy but being sensible! It’s good to be cautious around power tools.
OP, to answer your question: never noticed anything like this in any of my power tools, be they Dewalt, Milwaukee, or Ryobi
Does it have a trigger lock/between fwd and rev ? Are you using it ? Possible it bounces around just enough put pressure of the trigger and run just the slightest and drain the battery.
I don't believe it does but I will look into that.
I haven't had Dewalt power tools in over 10 yrs but none of my Milwaukees have noticeable parasitic drain, I leave the batteries in most of the tools I use regularly or periodically. If they did, that would drive me nuts & probably enough to get rid of them as I did with flashlights & other things.
Easy to check, grab a multimeter & measure the resistance between the main power terminals on the tool. Well might as well measure the resistance between all of them. There should not be any low resistance readings.
Now the cheap power tool adapters, the ones with USB ports, very commonly have parasitic drain, never leave them attached to a battery (obviously attached to the tool doesn't matter). The USB port circuit is what causes the parasitic drain. Even for Dewalt's own lithium to nicad adapter they say not to leave a battery attached to it.
I have a M18 to LXT adapter, it would take a while before noticing battery drain but it did which I was not having it. I didn't care for the USB port anyway so I started removing components out of circuit (ended up being just resistors & the main IC) until I got no more resistance readings. Finally I was left with just capacitors charging up which shouldn't really matter but I removed those caps out of circuit also.
Easy to check, grab a multimeter & measure the resistance between the main power terminals on the tool. Well might as well measure the resistance between all of them. There should not be any low resistance readings.
Now the cheap power tool adapters, the ones with USB ports, very commonly have parasitic drain, never leave them attached to a battery (obviously attached to the tool doesn't matter). The USB port circuit is what causes the parasitic drain. Even for Dewalt's own lithium to nicad adapter they say not to leave a battery attached to it.
I have a M18 to LXT adapter, it would take a while before noticing battery drain but it did which I was not having it. I didn't care for the USB port anyway so I started removing components out of circuit (ended up being just resistors & the main IC) until I got no more resistance readings. Finally I was left with just capacitors charging up which shouldn't really matter but I removed those caps out of circuit also.
Jay H 237
Well-known member
I had this happen a few times! My 20v Dewalt bag has two drills, four batteries and the charger. After putting the stuff in the bag and putting it down I've heard a faint whine/hum several times. The stuff would shift at times and faintly press against the trigger just enough but not enough it would turn the chuck. I now have the habit of pulling the batteries before the tools go in the bag.
BillK
Well-known member
Could it just be a defective battery ? If you take the battery out of the tool and let it sit does it keep its charge ?
I have two Dewalt 20v drills and the battery stays in both of them and has never been a problem.
I have two Dewalt 20v drills and the battery stays in both of them and has never been a problem.
Tchicken
Well-known member
I have a number of DW 20V tools and a number of batteries. I routinely leave a battery in the worklight, the drill, dustbuster and the leaf blower. The chainsaw, reciprocating saw, impact gun and tire compressor only see batteries when used. I've not noticed any parasitic draining on any.
I have tried and tested both of the 5Ah PowerStack batteries. Both will die within a week if left in the tool and both are still sitting at full charge when I checked them earlier today unattached since when I started this thread.
I have two things I want to check first but I expect to be sending the DCF961 back to Dewalt for them to look at; hopefully by this time next week. I forgot I had a very nice e-gift card from Acme Tools, so I have already ordered this tools replacement.
csp
Well-known member
I've had 20v Li batteries go dead if left in 18v NiCad tools using the adapter. Have not had any die if left in actual 20v tools made for those batteries.
Never experienced any form of parasitic drain in a power tool.
I will note that the combination M18 fuel drill/impact set has the batteries installed in both power tools but with a plastic film over the contacts you have to remove. I'm guessing that is more for accidental engagement of the tool in transit than any sort of electrical purpose.
I will note that the combination M18 fuel drill/impact set has the batteries installed in both power tools but with a plastic film over the contacts you have to remove. I'm guessing that is more for accidental engagement of the tool in transit than any sort of electrical purpose.