M18 Batteries Running Hot

[sab]

Last night after work, I was using an M18 angle grinder with a wire brush to prepare some columns for the shop mezzanine I'm building for primer. It was about 100°F outside. I was using 6Ahr and 8Ahr High Output batteries. The columns are 3-1/2" square tubing about 9' long. I couldn't even complete two sides of a column before the batteries (it happened with three different batteries) went into over-temp mode and quit working. That was probably 5 minutes, maybe 10 minutes of running. If you've run grinders in high ambient temps, what has your experience been? Do you have to rotate batteries and cool them down?

Thanks,
sab

 

[2001slvrstntj]

I have had this issue with Dewalt batteries in the past too on long cut with a saw. If I stopped for just a short time now and then battery lasted much longer….for whatever that might be worth.

 

[pagrey]

Those cells, 18650s are basically overheating 10 degrees over the outside temperature you are using them. They have to be cooled or you will get reduced battery performance and battery life. It's simply too hot to use those batteries in that heat without active cooling and not permanently damage them. Larger batteries have cooling systems to prevent damage, small hand tools don't. It sounds stupid but you might setup a (dry) cooler for them to prevent damage, those batteries ain't cheap.

 

[2001slvrstntj]

Maybe not ideal but when mine have over heated and would not take a charge I put them in the freezer or frig for a few minutes to cool them down faster.

 

[sab]

Thanks, fellers! I guess when it's stinkin' hot like this, I'll have to switch batteries often and cool them down. Kinda the same thing I have to do with this old bag of bones I inhabit these days...

 

[mrblaine]

Thanks, fellers! I guess when it's stinkin' hot like this, I'll have to switch batteries often and cool them down. Kinda the same thing I have to do with this old bag of bones I inhabit these days...

We use the crap out of ours when it is hot out like it is now. We likely aren't running them as long nonstop

though but I won't have an issue needing to swap to a cooler battery.

 

[HornedToad]

I’ve gotten a 5.0xc battery to shut down early from overheating. That was with my m18 fuel grinder really leaning into it hard with the flapper disc. The tool itself was quite hot too. I have some HO 6.0 batteries that do a lot better.

 

[sab]

We use the crap out of ours when it is hot out like it is now. We likely aren't running them as long nonstop

Yeah, I do end up running them a long time on the columns. Here they are (only the bottom one was brushed):

But that's the easy stuff. I also need to lightly brush two of these 30' long x 2' tall beams because they are more rusty:

If you look at the end of the beam closely, you'll see that I used a saw (the M18 steel-cutting circular saw - what a beast that thing is!) to cut through the flanges, but since I didn't feel safe or confident trying to plunge-cut the web, I used plasma to cut it. The cleanness of the saw cut edge is astounding.

though but I won't have an issue needing to swap to a cooler battery.

I have a similar setup, but I went with steel battery holders (eBay):

I didn't even know about the High Output M18 batteries until I saw one of your posts a while back, Mr. Blaine (thanks!) They are nice, but as I've just recently learned, they are best used for long run-time projects in the winter!

 

[mrblaine]

Yeah, I do end up running them a long time on the columns. Here they are (only the bottom one was brushed):

View attachment 347943

But that's the easy stuff. I also need to lightly brush two of these 30' long x 2' tall beams because they are more rusty:

View attachment 347944

If you look at the end of the beam closely, you'll see that I used a saw (the M18 steel-cutting circular saw - what a beast that thing is!) to cut through the flanges, but since I didn't feel safe or confident trying to plunge-cut the web, I used plasma to cut it. The cleanness of the saw cut edge is astounding.



I have a similar setup, but I went with steel battery holders (eBay):

View attachment 347945

I didn't even know about the High Output M18 batteries until I saw one of your posts a while back, Mr. Blaine (thanks!) They are nice, but as I've just recently learned, they are best used for long run-time projects in the winter!

I don't own enough flashlights to use all of those.

 

[sab]

I don't own enough flashlights to use all of those.

They also work just fine for drills and the hex impact guns. That's about it, though. Milwaukee likes to give you those for free, and I love free stuff!

 

[sab]

Yesterday I finished wire-brushing the columns. I ended up switching between three angle grinders - two M18 cordless and one corded Milwaukee grinder - to be able to keep working in the heat. In between uses, I removed the battery and set the grinder and battery in front of a centrifugal floor fan I have in the shop to cool it. Even doing that, I ruined the 15-year-old corded Milwaukee grinder. All of a sudden, the brushes started sparking like it was Independence Day again. I took it apart, and two of the commutator bars on the armature are displaced and deformed.

Years ago, I switched from DeWalt to Milwaukee power tools because my local repair shop said they repaired fewer of those than any other brand. That grinder lasted a lot longer than my DeWalts ever did, but I'm miffed because the armature is now obsolete, so I can't repair it. It's cool that the "new Milwaukee" is very innovative and their stuff works, but it seems to be at the expense of obsolescence. When they made the same grinder for years, the parts never changed, so they never went obsolete...