Not seen any round compact batteries unless you mean the older style ?
Neither round or compact though.
Milwaukee or Bosch? Small batteries
as opposed to the higher capacity ones:
I have a Milwaukee M12FPDXKIT with an M12JS and an M12FQID oil impact driver and I've been pleased with them, but they don't replace my Makita LXT 18 volt kit
To start with I want a combi drill driver and probably a circular saw.
Not really sure I need an impact driver but most sets seem to have them.
Other tools I would eventually like are a grinder and a jigsaw.
For what I do would I be better off going for a 12v ( but with more batteries) or 18v
I am more interested in whether for a diy use ( generally one tool at a time) 12v would suffice? Are the 18v more powerful than the 12v or do they just last longer?
Also is it worth paying the extra for brushless?
!8 volt tools are more powerful than 12 volt tools, so it isn't just a question of run time.
Cordless grinders are only available if you go to 18 volt, however, from personal experience I'd say that unless you opt for a brushless model with several high amperage batteries (5Ah and above) you will struggle to grind or cut much with one - and they are no substitute for a corded tool if you are doing heavy cutting or grinding (such as mortar raking, cutting steel plate, etc). If all you are doing is pinging off the odd protruding bolt or removing a few nail heads where a soffit board was then a cordless (even a brushed one) will do the job, just don't expect long battery duration, especially with brushed models. However, if you want to cut 100 x 100 x 3mm angle steel section you are into corded country unless you feel inclined to buy at least 3 no 5Ah batteries and ideally a brushless grinder (so £250 plus for that alone without a charger).
Similarly, whilst there are 12 volt saws around (for example Milwaukee do a really nice one)
they are a bit more limited in capacity than an equivalent 18 volt saw such as the Makita DHS680:
with 44mm depth of cut (Milwaukee) vs. 57mm (Makita) at 90 degrees. Having had earlier brushed 18 volt cordless saws I'd point out that they are low powered and struggle on heavy cuts in comparison with the brushed models - they can cut 18mm plywood and 3 x 2 CLS, but you aren't going to be able to trim a 44mm fire door to length with one. I went from a Makita DSS610 (brushed) to a DHS680 (brushless) about 5 years ago and it was like night and day - much more oomph, made cuts the brushed tool would baulk at and is generally a far more useful tool. In budget terms, though, a corded saw still wins hands down as I could buy a "branded" 190mm corded saw for less dosh than a 165mm cordless would cost BARE (circa £150)
Combi drills are OK, but the lower priced ones have nylon gears and plastic gearboxes, so they are limited in what they can drill. If you driull a lot of heavier stuff you would be better off going for a top of the range model with a metal gearbox and metal gears, or better still a drill and an SDS drill. Brushless gives you more power and better run time, but it does cost more.
Finally cordless jigsaws are great. Again the brushless ones have far better run time (I went from a Makita DJV180 to a DJV181 - more because I wanted a body grip for doing scribes and my 180 was by then 7 or 8 years old) and a bit more capacity. One plus of the 18 volt ones over 12 volt ones like the Milkwaukee M12JS
is that the 18 bolt tools have variable orbit - the 12 volt ones don't seem have this feature, but they are a lot more compact and can get into far smaller spaces than their 18 volt cousins
Finally batteries - the trade brands like Makita and Milwaukee will support their tools for the foreseeable future with parts and batteries available for years to come, but they cost more. Will lower grade brands like Erbauer or Worx offer that continuity?
Comments based on my own experience of using Makita LXT 18 volt for about 12 or 13 years and Milwaukee M12 for 2 years. I have used equivalent Bosch 10.8 volt and DW 18 volt stuff and they seem just as competent, theyjusty didn't offer a brushless repleceable head drill when I bought my Milwaukee (nor an oil impact driver)