About Cordless Tools - What does more VOLTS really get you?

[musgofasta]

I'm currently in the market for a cordless kit, almost certainly Lithium Battery based.

My question is about Battery Volts - What does more Volts typically do? More specifically, do 18v drills generally run at higher RPM's, or last longer, or just have more "power" than 14,12,10.8 volt stuff? Lots of times, the specs look real close except for weight.

Looking at drills and impact drivers

Ryobi 18v impact driver - 1200 in/lbs torque
Ryobi 12v impact driver - 800 in/lbs
Makita 12v Impact driver - 1110 in/lbs torque
Makita 10.8v compact impact - 800 in/lbs and under 2 lbs.

Makita 10.8v drill - 1300 rpms
Makita 12v drill - only 1200 rpms

Are the Lithium-based tools more EFFICIENT, meaning for example 14v lithium is comperable in power to 18v Nicad? The waters get muddy when you start comparing cost increase vs. spec increase.

The Makita 10.8's look damn bitchin' when you compare the specs, especially the weight, to other bigger sets. But do 10.8 batteries die quicker, meaning less work before recharge? Need help from the Pro's.

 

[48548]

This is the one I have and I am curious about the same thing? How does this compare with the info from above?


Milwaukee V28™ 1/2 in. Impact Wrench Kit

FEATURES


Revolutionary 28 Volt Lithium-Ion Technology

325 ft.lbs of maximum torque

Variable Speed: 0-1450 rpm, 0-2450 ipm

Up to 2x run-time of 18V tools

Hanger Bracket with solid steel ring

Magnesium Gearcase for added durability and lighter weight



SPECIFICATIONS


Voltage 28 DC

Drive Size 1/2 in. Square

Torque 3,900 in.-lbs./325 ft.-lbs.

No Load Speed 0-1,450 RPM

No Load BPM 0-2,450

Reversible Battery Yes

No. of Batteries Included 2

Amp Hours 3.0

Trigger Lock Off

Electric Brake No

Length 12-1/8 in.

Tool Weight 8.9 lbs.

Shipping Weight 19.1 lbs.

 

[Stuey]

Oh, goodness. I'll try to restrain from breaking out an essay. I don't know enough about impact drivers, so I'll only address your inquiry with respect to drills/rotary-only drivers.

More volts typically mean greater power. More power = greater overall torque capabilities and at a given speed.

Higher voltages tools sometimes come with more or better features. If you want a drill with a 1/2" chuck, don't look for anything less than 14.4 or 18V.

Just because a tool has a higher voltaged power source doesn't make it better, you need to consider the other specs. For example, there are 18V drills that are more powerful than Craftsman's 19.2V drills. The decision to produce a 19.2V drill was likely a marketing one. That's not to say that 24V and 36V tools from reputable companies aren't more powerful, because they are. But if you see, say, a non-branded drill rated at 24V and priced at $40 at the nearest discount store, stay away.

I have found that RPM are relatively similar among drill classes. I needed higher RPM in a corded drill and had to go with a hammer drill b/c the rotary speed on almost every other 1/2" chuck corded drill I found was 850 RPM, which was too slow for my needs.

Lithium power allows for a more compact, lighter battery. A lithium battery the size of say, a NiCad or NiMh battery, would be capable of a greater capacity, rated in amp-hours.

If I'm not mistaken, lithium batteries are also capable of handling a greater discharge rate, so they could feed more power-hungry tools.

Consider voltage as you would water pressure in a pipe - 14V lithium is not comparable to 18V non-lithium.

What are you looking for, power, or portability? We need to know your exact requirements before we can help you narrow down your options.

Start off by considering your intentions, and go from there. Many/most compact drivers only have a 1/4" hex drive chuck, which is not advised if you plan on doing a lot of drilling with many different types of bits. If you plan on drilling 1/4" holes in 1/4" plywood, your needs will be much different than someone who needs to drill 3" holes in 1/4" steel.

 

[48548]

the other thing about lithium-ion, is that it is consistant power, to the end, the voltage doesn't drop like on ni-cads IE: when the battery gets weak, the drill get slower....

 

[ddawg16]

Likey Steuy said....the higher the voltage, the more power....generally....

With higher power you have less losses in the wiring and other associated parts.

Based on what I'm seeing..18V seems to be about the ideal voltage for portable tools....

What is more important is the battery, it's internal resistance and ability to deliver power to the motor in the tool. Litium has more energy density (total power), but IIRC, it's internal resistance is higher than NiCad's...but in most cases, this is not a big deal (or I may have it backwards...need to check).

What ever you do...settle on a brand and stick with it....no reason to have 2-3 different types of batteries and chargers. I would highly suggest buying a kit that includes a drill, 5 1/4" saw, and Sawsall. They typically come with 2 batteries and 1 charger....you can add to it as necessary.

I have the Ryobi stuff....it does a fine job for what I use it for. The 'only' tool that is not up to par is the right angle drill....not enough power and gets too hot too fast. I'm taking it back this weekend.

Dewalt's and Millwalkee's are great tools...but you pay for them. For the weekend casual stuff I would suggest Ryobi. If it's your job...then Dewalt or Millwalkee.

BTW...plan on at least one good corded 1/2" drill....

 

[musgofasta]

Thanks Stuey -

I do far more driving screws than drilling holes, which is why I'm perfectly fine with the hex chuck. Building cabinets, shelves, and other things around the house.

My current drill is the standard Ryobi 18v Nicad, about 4 years of steady homeowner abuse. It drills fine, but DRIVES pretty poorly. It struggles in the 3-inch deck screw into stud test, which is why I'm looking for an impact driver also. Torque is 350 in/lbs, which compared to the Makita 10.8 impact's 800. Battery's are pretty much DOA, so if replacing batterys and getting an impact, might as well look at other options. Fullsize drill and Nicad's are plenty heavy on the ladder also.

Thanks.

 

[speed bump]

Its very simple, power = volts x amps. Higher voltage=lower amperage draw for the same amount of power and thus better battery life.

 

[musgofasta]

DDawg -

My garage experiences has me reaching for the corded saws far more often. After getting the Ryobi drill and saw combo, I thought I'd be adding more of them down the line. But I'd rather have the quality plug-in saws. Yes I love the options of all of the Ryobi cordless systems, just haven't utilized it to the fullest.

 

[The Muffin Man]

Lithium-Ion batteries also have no "memory." what this means is that the battery will not loose it's charge capacity regardless if the battery is not fully discharged before recharging. Also Li-Ion batteries also have a higher resistance to loosing their charge when not used/charged for long periods of time.

If you have the extra cash, go for the Li-Ion batteries. You'll save twice the amount three years down the road (NiCd will probably be almost completely phased out by then.)

 

[Crasen]

Thanks Stuey -

I do far more driving screws than drilling holes, which is why I'm perfectly fine with the hex chuck. Building cabinets, shelves, and other things around the house.

My current drill is the standard Ryobi 18v Nicad, about 4 years of steady homeowner abuse. It drills fine, but DRIVES pretty poorly. It struggles in the 3-inch deck screw into stud test, which is why I'm looking for an impact driver also. Torque is 350 in/lbs, which compared to the Makita 10.8 impact's 800. Battery's are pretty much DOA, so if replacing batterys and getting an impact, might as well look at other options. Fullsize drill and Nicad's are plenty heavy on the ladder also.

Thanks.

If you are not happy with the way that an 18v Ryobi drill drives screws then I doubt you would be happy with the way a 10.8v impact will. I have an 18v Ryobi drill and a 10.8v Bosch impactor and the Ryobi drill will run circles around the Bosch impactor when driving 3 inch deck screws.The torque specs on the impactor is nowhere near what it will actually achieve either.

 

[musgofasta]

Hmmm...well then I'll probably stay with the Ryobi and just get a lithium battery and their impact. Keep my same drill and skill saw for use with the lithium's.

 

[musgofasta]

My local HD had the Makita 10.8 Drill and Impact set on clearance for 129.99, so I couldn't pass them up at that price. I figured I'd return them if they didn't meet my power needs.

Got them home, and BOTH of the batteries are charged right out of the package. These things are unbelievable! Drive screws better than my 18v Ryobi. Does everything I could ask for. Only thing I maxed it out on was big spade bits, but I don't use those very often anyway.

Couldn't be happier, especially for $130. Recommend checking to see if your HD has them marked down!!!

 

[sasquatchpa]

I use a lot of drill/drivers at home/work. Between h/w I have a dozen Dewalt 18v tools and a few 14.4 Mil. If I were buying a general purpose driver and didn't need to stay in a family it would be the new 12v Milwakee. The 18v Dewalt is nice w/ Lith/ion.

 

[IDASHO]

Anybody check out the latest issue of Fine Home Building?


I got mine yesterday, and breezed through it right before dinner. Seem to remember an article talking about tool companies finding a standardized method of rating power tool output.

 

[HolisticPerformance]

Consider This -

As said, VoltsXAmps=Watts (power you can use). The amount of load you put on the drill will increase the amount of amps consumed, the amount of "throttle" you give the drill will typically increase the voltage sent to the motor. Think of amps and voltage like as a water hose - Amperage equals the amount of water flowing through the hose, while Voltage represents the pressure of the water in the hose. Voltage is electrical pressure, amperage is the amount of electrons flowing. SO, 20 amps at 120 volts is MUCH MORE energy than 20 amps at 12 volts.
This said, a higher voltage battery will most likely produce a stronger drill, with greater potential for a longer-life battery.


Lithium-Ion batteries - just a different chemical make up for the battery materials that produce engergy. Lead Acid (regular car battery) batterie use Lead and Sulphuric acid to generate electron movement (which is the very definition of Electricity). Lithium ion does something similar, only with different chemicals. A lithium-ion battery will produce Six times as much energy as a Lead acid battery with similar weight and size. This is the biggest reason/advantage that power tool manufacturers have started using this type of battery -Much more power (six times as much) with the same size and weight of a regular battery.