View Single Post
  #10   Report Post  
Posted to uk.d-i-y
Theo[_3_] Theo[_3_] is offline
external usenet poster
Posts: 1,264
Default Is 14V cordless sds drill ok for diy?

Mike Halmarack wrote:
On Wed, 21 Apr 2021 05:44:53 -0700 (PDT), Murmansk

I've got a Makita 18V SDS drill and it's very good - although I've only
used it for drilling 6.5mm holes in very hard brick and concrete, which
it does well.

Very clearly put. But not encouraging in terms of the viability of the
14v version.

What we're concerned about here is the power delivered. P=V^2/R and so the
power increases with the square of the voltage. However what isn't
discussed is decreases in the resistance which will also contribute. An
improved battery with a lower internal resistance can deliver more power,
even at the same voltage. This is why a lithium ion drill is better than a
NiMH of the same voltage - the NiMH has a higher resistance and so can't
deliver as much current.

However it's hard to beat a square law, so I would be looking at trying to
get the higher voltage.