Cordless tool battery life

[Hobby_Man22]

How long does the charge last on these batteries? I havent worn one out yet. Finally moved over to the darkside and got some cordless tools.

Mine are 20v dewalt batteries. I bought like 4 extra batteries of various amp hours. Should probaly have just bought all 2amp hour batteries, haven't worn one of those out and is it really that big a deal to switch out a battery? They have chargers on facebook marketplace for $15 I bought a couple chargers too.

 

[Hobby_Man22]

I just use it in a drill mainly drilling screws in.

 

[Bogie1632]

What brand did you go with? What size batteries. Amongst other factors it depends on the amp hour rating and how hard you use it. Running a small bit in wood versus augering out holes for conduit. Small screws versus lag bolts. Larger amp hour batteries on your platform will last longer, but also take longer to charge.

I didn't count screws but used a cordless Milwaukee (borrowed) with a 5.0 battery (newish, mine) to hang drywall in my kitchen recently. It handled about 18 sheets worth of screws and a couple extra days of use on other drilling and cutting stuff before it went back on the charger and it wasn't dead at that point.

V/R
Bogie

 

[iamrfixit]

No big deal to change out a battery, just slide the old one off and slide the new one on. You should always charge your dead batteries right away. Lithium batteries must not be left in a discharged state as they can become unable to charge and extended low voltage conditions can actually damage the cells. Lithium can be charged at any time, they don't suffer memory issues like the old nicad batteries did.

Battery life depends on the tool you're running and the work you are doing. Driving a few screws here and there with an impact driver a battery might last days. Running long screws in, one after another continuously might drain the battery in an hour.

High speed tools like a grinder can drain a 5ah battery in 5-10 minutes of continuous use.
The compact 2ah batteries are fine for tools that don't draw a lot of power, like a flashlight or drill/impact driver with limited use, but not so good for something like a circular saw. High drain tools used with a small battery will significantly lower the performance of the tool.

Still have my first 20v batteries from 10-11 years ago and they still work perfectly. I accumulate a few new batteries each year, often included free as I'd add a new bare tool or find a bargain on a tool kit that includes batteries.

 

[Hobby_Man22]

So should I just stick them right back on the charger when done even if they're still at 80 percent charge?

 

[Tuc04]

80% charge seems to be around the ideal if you want them to last as long as possible. There’s a lot of information out there about lithium battery life, but here is some I found quickly.

Tips for extending the lifetime of lithium-ion batteries

ANN ARBOR—Lithium-ion batteries are everywhere these days, used in everything from cellphones and laptops to cordless power tools and electric vehicles. And though they are the most widely applied technology for mobile energy storage, there's lots of confusion among users about the best ways to pro

news.umich.edu

 

[Hobby_Man22]

I thought these batteries weren't susceptible to discharge issues.

 

[Hobby_Man22]

Half the people claim they are and half don't.

 

[bassJAM]

Use depends on the amp hours of the pack and what you're doing with it. The 1.5 ah slimpacks with my Bosch will run a small drillbit through wood forever and drive a ton of drywall screws. But a handful of crosscuts through studs with a circular saw will drain them pretty quick so I step up to a 3.0 ah. Then there's my SDS hammer drill that I run an 8 ah battery with.

 

[engineer2]

I thought these batteries weren't susceptible to discharge issues.

My Makita batteries can sit around for a month or two and still be good to use. Probably the same for other brands.
Avoid running the battery down to nothing.
It's perfectly fine to charge them when they are only partially run down.

 

[Bogie1632]

Personnaly, I think that's hit or miss. Of the millions made by various manufacturers there is bound to be a few in the mix with issues. These newer style batteries have computers on them as well that can cause issues but they also help these batteries run better than ever. My 12+ y/o Makita batteries do discharge on their own and have for years....but it takes a while. New they were great but they also don't hold the same charge they used to. My Milwaukee batteries have been great and have no discharge issues...but a family member and friend who run them as pros have had issues even on new ones. Rare, but they still happen. Not abusing and properly maintaining your batteries IAW the manufactures recommendations definitly helps them last longer.

Half the people claim they are and half don't.

V/R
Bogie

 

[minke]

I thought these batteries weren't susceptible to discharge issues.

If you are referring to the "memory effect" that applies to NiCd batterys, so you are correct.

 

[M635_Guy]

So should I just stick them right back on the charger when done even if they're still at 80 percent charge?

I would say "no" if you value longevity of the battery itself over maximum charge per session

 

[M635_Guy]

My Makita batteries can sit around for a month or two and still be good to use. Probably the same for other brands.
Avoid running the battery down to nothing.
It's perfectly fine to charge them when they are only partially run down.

True, but charging to top from a highly-charged state (call it 70%+ to 100%) wears out the batteries faster than if you charge from 50% to 80% or similar. Trickle-charging between 80% and 100% is also better than rapid-charging (slower the better)