DeWalt Flexvolt 18 vs 54

[a twig]

Slightly tangential to usual posts on here - but I am very much on the DeWalt train for power tools (to the extent that I even converted my daughters toy ride on tractor over to run on 2x 5Ah battery packs - giving it a faster top speed and a 4 hour run time va the original 40 minutes ), but I am getting to the point where some of my 18V packs are getting towards the end of their lives and need replacing.

One of my big bugbears is the overheating, when using tools like a strimmer, grinder or chainsaw, the batteries get hot enough for the over temp cut off to kick in and so I either have to swap out the pack or wait for it to be able to cool before cracking on.

As I currently only have 5Ah 18V batteries I was getting quite excited about the 9Ah Flexvolt but can’t find any information about whether the Flexvolt have better thermal management when used in 18V tools, i.e, will I actually see the full benefits of the 9Ah or will I still be juggling battery over temps?

Anyone got any experience that might help?

And just to be clear this definitely isn’t me looking for an excuse to replace all my 18V tools with 54V (other than maybe the chainsaw, oh and the blower, and, and…)

 

[fernicarry]

Hmm, no experience of DeWalt, but from a purely electrical pov I don't think it would be any different. When running at 18V the tool will draw the same current so the heating effect will be the same. On 54V there will be less current and less heating for the same power demand but you'd need new tools for that.

I get the same with my Bosch tools sometimes. They stop not because they are discharged but because the long run time with things like the strimmer or sander makes them over heat. And more annoyingly they won't start charging until they cool down either.

Actually its possible that the flexvolt has a worse heating problem because there must be some switching electronics inside it to reconfigure the cells for 18 or 54V and those electronics will have a small voltage drop that generates heat.

 

[a twig]

That was my gut feeling as well, I was hoping someone would be able to convince me that these newer batteries contain witchcraft and it’s no longer an issue or something like that

 

[a twig]

Oooh - “people of the internet” have said:

The 54V packs do run cooler - the cells have lower internal resistance, and the draw is split over 3 cells in parallel, not 2.

Maybe I buy one and give it a go…

 

[Cubist]

@a twig snapped...... and broke so easily with almost no pressure at all needed to tempt him into Toolstation.

 

[a twig]

Me, using advice from the good folk of this parish to provide family political top cover to justify things I want to do?

Never…

(Well maybe once or twice…)

 

[fernicarry]

the cells have lower internal resistance, and the draw is split over 3 cells in parallel, not 2

That would make sense. I suppose there's only one way to find out... Hell of a price for one battery though!

 

[a twig]

Yeah fair point, might go for the 6Ah as the “give it a test” - I’m allegedly getting a £50 voucher as a long service award from work soon so that might take the edge off

 

[s27y]

I'm committed to the DeWalt 20V system, favouring newer XR batteries with enhanced thermal management for high-output applications over the more expensive Flexvolt. A cheaper, potentially superior alternative is building a custom battery pack with a DIY kit and quality cells (30amp+).