On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

"The Medway Handyman" wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?


It depends what you mean by power. In terms of the capacity of the
batteries to hold stored electric power, yes, they are similar.

But most people would consider "the same power" to mean the tools
having equal ability to perform similar tasks. And that depends on
many things, only one of which is the stored electric power. The
maximum torque might well be higher on people's list of priorities.

The Medway Handyman wrote:
On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?


What they say might be true as related to the power of the battery - but
not the machine!

What they say might even be true for a specific pair of drills.

We have on our cars motors ranging from, say, small fans through to the
starter motor. And, when the engine is not running, all are driven by
12V from a single battery. Clearly power delivered by each of these
motors varies massively and is not related to the voltage.

And it is quite possible for two batteries of a given nominal voltage
and ampere-hour capacity to have very different abilities to deliver.
Especially if they are different technologies (e.g. Nicad and LiIon).

I read it as Worx want to flog 12V stuff and so they are claiming it is
as good as 24V stuff. It might even be true for Worx' 24V products... :-)

--
Rod

Hypothyroidism is a seriously debilitating condition with an insidious
onset.
Although common it frequently goes undiagnosed.
www.thyromind.info www.thyroiduk.org www.altsupportthyroid.org

In article , The Medway Handyman wrote:
On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

Only if the batteries last the same time. Ah measures energy, not power.

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "The Medway Handyman"
saying something like:

"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

Only superficially. I'd rather have a good 24V machine than a good 12V
machine. Crap ones, they're well... crap anyway, so the comparisons are
meaningless.

"The Medway Handyman" wrote in message
om...
On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine
is. This is only partially true. If you do the math of combining voltage
with Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah
battery has the same power as a 24 V drill with 1Ah battery."

Is that true?

Does it matter?

When you are buying siad equipment what would you consider?

"The Medway Handyman" wrote in message
om...
On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine
is. This is only partially true. If you do the math of combining voltage
with Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah
battery has the same power as a 24 V drill with 1Ah battery."

Is that true?

Yes.
There is no real advantage in having 24V rather than 12V as far as the tools
ability to do work is concerned.
It is a common misconception that if its a higher voltage it will work
better.
However those same people will be quite happy to swap a 18V drill for a
10.8V drill using Lithium batteries.

RW wrote:
"The Medway Handyman" wrote in
message om...
On the Worx website http://www.worxtools.com/Technologies.aspx it
says re cordless tools;


"Most people think the higher the voltage, the more powerful the
machine is. This is only partially true. If you do the math of
combining voltage with Ah, you may be surprised. Believe it or not,
a 12 V drill with 2Ah battery has the same power as a 24 V drill
with 1Ah battery." Is that true?

Does it matter?

When you are buying siad equipment what would you consider?

I wouldn't buy Worx anyway, I'm a Makita bloke. Just interested, sounded
like bollox to me.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

Not really. It's a matter of torque. A 24v drill with decent gearing
has far more than a 12v even with decent gearing.

More electrical pressure you could consider it as.

"EricP" wrote in message
...
On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine
is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

Not really. It's a matter of torque. A 24v drill with decent gearing
has far more than a 12v even with decent gearing.

More electrical pressure you could consider it as.


I have a Nutool 24v cordless and a Dewalt 12v cordless ...
They both have impressive and equal torque, and the batteries last about the
same.
I love them both.
Dave

The Medway Handyman wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;

There are some other gems of bull dodo on that page:

"Just think about your car's gas tank: the bigger it is, the less you
have to stop at gas stations."

"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

No. The first bit is ok, however the use of the word "power" in the last
sentence is definitely wrong.

The product of voltage and cell capacity gives a figure for overall
energy stored. So you could say that all other factors being equal the
12V tool could achieve the same amount of work as the 24V tool. However
power relates to the rate of doing the work. So with otherwise equal
tools the 24V will be able to deliver that work in less time. There are
two implications of this, one being that you ought to be able to do some
tasks faster (say drill a certain size hole, or drive a given screw. The
other being that there are some tasks that you will only be able to
perform with the higher voltage tool since you require faster delivery
of energy - i.e. drive a large diameter drill bit or hole saw.

Reality however is somewhat more grey. Often higher capacity cells are
also better quality cells and will be able to deliver higher peak
currents. Better quality drills will also usually have better cells.
They may be better matched as well, which will allow the tool to extract
more of the total energy content in a usable form.

So as Dave's reply to EricP nicely demonstrates, The cheap 24V tool with
crap batteries, poorly toleranced gearbox, cheap motor, and rough speed
controller (no offence Dave!) may be equalled in performance by a high
quality tool of half the voltage. What is more the 12V tool will
probably be smaller and lighter into the bargain.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
The Medway Handyman wrote:
"Most people think the higher the voltage, the more powerful the machine
is. This is only partially true. If you do the math of combining
voltage with Ah, you may be surprised. Believe it or not, a 12 V drill
with 2Ah battery has the same power as a 24 V drill with 1Ah battery."

Is that true?

The size/type of the battery has nothing to do with the power of the tool
- assuming it is capable of delivering enough current for that maximum
power. The power of the tool is entirely down to the motor.

That's not to say there isn't an ideal voltage for cordless tools - rather
the same as with tungsten lamps. But I don't know what that is.

However, the quality of the cells *does* make a big difference - good ones
can supply a lot more current. So a cheap 24v battery could well not be as
good in practice as a decent 12 volt one.

I've got an 18 volt B&Q drill. One of the batteries for that I've
re-celled with Sanyo. And it performs far better than new with that
battery. Basically, more torque.

--
*Be more or less specific *

Dave Plowman London SW
To e-mail, change noise into sound.

A 12v motor can give the same power as 24v motor.
The battery size (energy stored) makes it go longer.

Two drills one 12v one 24v, giving the same power.
Both have a 2Ahr battery

The 24v motor drill will last longer.

To users, the convention fior users is that the higher the voltage the more
powerful the drill. Makers market it that way for their understanding. In
general a 24v in the current market will ne more powerful.

"Doctor Drivel" wrote in message
...
A 12v motor can give the same power as 24v motor.
The battery size (energy stored) makes it go longer.

Two drills one 12v one 24v, giving the same power.
Both have a 2Ahr battery

The 24v motor drill will last longer.

To users, the convention fior users is that the higher the voltage the
more powerful the drill. Makers market it that way for their
understanding. In general a 24v in the current market will ne more
powerful.

A red letter day! Above, DD speaks nothing but the undeniable truth! )


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)

"John Rumm" wrote in message
...
The Medway Handyman wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;

There are some other gems of bull dodo on that page:

"Just think about your car's gas tank: the bigger it is, the less you have
to stop at gas stations."

"Most people think the higher the voltage, the more powerful the machine
is. This is only partially true. If you do the math of combining voltage
with Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah
battery has the same power as a 24 V drill with 1Ah battery."

Is that true?

No. The first bit is ok, however the use of the word "power" in the last
sentence is definitely wrong.

The product of voltage and cell capacity gives a figure for overall energy
stored. So you could say that all other factors being equal the 12V tool
could achieve the same amount of work as the 24V tool. However power
relates to the rate of doing the work. So with otherwise equal tools the
24V will be able to deliver that work in less time.

If everything is "otherwise equal" they will perform identically.

The 12V motor needs to deliver the same amps x turns as the 24V motor to
give the same "power".
It has twice the AHr capacity so it is quite able to do so for the same
time.

The 24V one could deliver more amps x turns as the 12V but then it wouldn't
last as long.

At practical levels there is unlikely to be much difference between two
drills aimed at the same sector.

Just look at the new Lithium stuff its 10.8V but performs as well as the 18V
if not better.


There are two implications of this, one being that you ought to be able to
do some tasks faster (say drill a certain size hole, or drive a given
screw. The other being that there are some tasks that you will only be able
to perform with the higher voltage tool since you require faster delivery
of energy - i.e. drive a large diameter drill bit or hole saw.

Reality however is somewhat more grey. Often higher capacity cells are
also better quality cells and will be able to deliver higher peak
currents. Better quality drills will also usually have better cells. They
may be better matched as well, which will allow the tool to extract more
of the total energy content in a usable form.

So as Dave's reply to EricP nicely demonstrates, The cheap 24V tool with
crap batteries, poorly toleranced gearbox, cheap motor, and rough speed
controller (no offence Dave!) may be equalled in performance by a high
quality tool of half the voltage. What is more the 12V tool will probably
be smaller and lighter into the bargain.

The size advantage should be in the 24V tools favor.
The copper can be thinner so the motor smaller than the 12V one.
But you will never know as the professional 24V tools are all aimed at
bigger jobs.
And the cheap 24V tools are aimed at the budget market and built down to a
price.

In article ,
Bob Mannix wrote:
"Doctor Drivel" wrote in message
...
A 12v motor can give the same power as 24v motor.
The battery size (energy stored) makes it go longer.

Two drills one 12v one 24v, giving the same power.
Both have a 2Ahr battery

The 24v motor drill will last longer.

To users, the convention fior users is that the higher the voltage the
more powerful the drill. Makers market it that way for their
understanding. In general a 24v in the current market will ne more
powerful.

A red letter day! Above, DD speaks nothing but the undeniable truth! )

Almost. He missed out the important part that a 24 volt from one maker may
not be as good a drill as a 12v from a better one.

--
*To steal ideas from *one* person is plagiarism; from many, research*

Dave Plowman London SW
To e-mail, change noise into sound.

On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

12v x 2A for one hour = 24W/hr
24V x 1A for one hour = 24W/hr

so yes it is true. However, there are many more variables such as the
motor design and battery type and quality which are more important.

Their central point, that battery voltage alone is not a reliable
indicator of the tools power, torque, longevity or work cycle, is
correct.

On 12 Nov, 20:41, "The Medway Handyman"
wrote:

Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Not at all. They have the same _capacity_, but the _power_ depends on
the motor the designers chose to fit. A big motor on a tiny battery
can have a huge power, but you'll be running to the charger every few
minutes. This is fine for an impact driver used for dismantling, a
damn nuisance with a power screwdriver assembling decking.

On the whole though, I'd consider their claim to be reasonable in
terms of capacity (number of small screws driven between charges), but
simply irrelevant about power. You have to know what the motor is.

Weight is as good a measure as anything you can read on the outside of
the box.

"Peter Parry" wrote in message
...
On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

"Most people think the higher the voltage, the more powerful the machine
is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

12v x 2A for one hour = 24W/hr
24V x 1A for one hour = 24W/hr


Irrelevant. You could fit the 24V drill with a 2Ah battery. This has no
effect on the current drawn, just how long the battery lasts. The fact that
a drill has a 1Ah battery does *not* mean it draws 1A!


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not

On Thu, 13 Nov 2008 11:05:09 -0000, "Bob Mannix"
wrote:

"Peter Parry" wrote in message
.. .
On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

"Most people think the higher the voltage, the more powerful the machine
is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

12v x 2A for one hour = 24W/hr
24V x 1A for one hour = 24W/hr

Irrelevant. You could fit the 24V drill with a 2Ah battery.

Or the 12V one with a 20Ah one. However the comparison quoted was
between 12V/2Ah and 24V/1Ah. In terms of stored energy these are both
broadly the same.

The advert is using the word "powerful" somewhat ambiguously but the
statement about the battery equivalence is reasonable.

This has no effect on the current drawn, just how long the battery lasts. The fact that
a drill has a 1Ah battery does *not* mean it draws 1A!

Of course not, what I was showing was that the amount of stored energy
in a 12V 2A/h battery is roughly the same as that stored in a 24V
1A/h battery.

Whether you would get the same amount of work from both depends upon
other factors such as the motor and how well the battery copes with
the load.

In article , EricP
scribeth thus
On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

Not really. It's a matter of torque. A 24v drill with decent gearing
has far more than a 12v even with decent gearing.

More electrical pressure you could consider it as.


Shows how much you don't know about electricity;(..
--
Tony Sayer

"Dave Plowman (News)" wrote in message
...
In article ,
Bob Mannix wrote:
"Doctor Drivel" wrote in message
...
A 12v motor can give the same power as 24v motor.
The battery size (energy stored) makes it go longer.

Two drills one 12v one 24v, giving the same power.
Both have a 2Ahr battery

The 24v motor drill will last longer.

To users, the convention fior users is that the higher the voltage the
more powerful the drill. Makers market it that way for their
understanding. In general a 24v in the current market will ne more
powerful.

A red letter day! Above, DD speaks nothing but the undeniable truth! )

You must eff off as you are an idiotic plantpot. Please put your finger in
the socket.

"Bob Mannix" wrote in message
...
"Doctor Drivel" wrote in message
...
A 12v motor can give the same power as 24v motor.
The battery size (energy stored) makes it go longer.

Two drills one 12v one 24v, giving the same power.
Both have a 2Ahr battery

The 24v motor drill will last longer.

To users, the convention fior users is that the higher the voltage the
more powerful the drill. Makers market it that way for their
understanding. In general a 24v in the current market will ne more
powerful.

A red letter day!

I've used French letters, not red ones.

In article ,
Doctor Drivel wrote:
A red letter day! Above, DD speaks nothing but the undeniable truth!
)

You must eff off as you are an idiotic plantpot. Please put your finger
in the socket.

For once you're right. The very idea of you talking sense.

--
*Ah, I see the f**k-up fairy has visited us again

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Doctor Drivel wrote:
A red letter day!

I've used French letters, not red ones.

If only your father had.

--
*Some people are only alive because it is illegal to kill.

Dave Plowman London SW
To e-mail, change noise into sound.

"Andy Dingley" wrote in message
...
On 12 Nov, 20:41, "The Medway Handyman"
wrote:

Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Not at all. They have the same _capacity_, but the _power_ depends on
the motor the designers chose to fit. A big motor on a tiny battery
can have a huge power,

A 12v drill can have "exactly" the same power a 24v drill. That is not a
problem. To have them last the same amount of time in drilling, the 12v
drill will need a bigger battery in A/hrs.

This adds cost as battery cells are expensive and are the main cost of a
drill.

So, as batteries are expensive compared to knocking out motors en-mass, they
go for larger voltage motors and then the batteries do not have to be as big
(or as heavy, which is major point). They are balancing one against the
other to keeps costs down. That is using the same type of battery of course,
say Ni-Cads.

Current marketing means that generally the larger the voltage the greater
the power - so the punter then can gauge the products on the market. All
understood, all de-facto standard.

Now, a 12v drill can be the same power as a 24v drill, no arguments about
that. Battery types are changing with Lith-Ion being introduced. That
means that a 12v drill can be the same power as 24v drill, but put a
Lith-Ion battery in it and matters change as these can be so much smaller in
physical size and hold so much more energy. So a 12v Lith-Ion drill can
match a 24v Ni-Cad drill in power and battery life and be at least the same
weight, or even lighter. BUT!!! That is comparing apples with oranges
(Lith-ion and Ni-Cads).

Using the same battery type we are back to stage one. Using 12v and 24v
Lith-Ion with the same power still means the 12v drill will need a larger
battery in A/hr to last the same amount of running time. Although all
drills using Lith-Ion will be smaller & lighter than Ni-Cads.

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
A red letter day! Above, DD speaks nothing but the undeniable truth!
)

You must eff off as you are an idiotic plantpot. Please put your finger
in the socket.

For

You must eff off as you are an idiotic plantpot. Please put your finger in
the socket.

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
A red letter day!

I've used French letters, not red ones.

If

You must eff off as you are an idiotic plantpot. Please put your finger in
the socket.

In article ,
Doctor Drivel wrote:
A 12v drill can have "exactly" the same power a 24v drill. That is not
a problem. To have them last the same amount of time in drilling, the
12v drill will need a bigger battery in A/hrs.

This adds cost as battery cells are expensive and are the main cost of a
drill.

So, as batteries are expensive compared to knocking out motors en-mass,
they go for larger voltage motors and then the batteries do not have to
be as big (or as heavy, which is major point). They are balancing one
against the other to keeps costs down. That is using the same type of
battery of course, say Ni-Cads.

You don't know that identical sized cells come in different capacities?
And don't vary in weight by very much?
Higher voltage drills impress the unwary at the bottom end of the market.
You should be well used to that.

--
*Be more or less specific *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Doctor Drivel wrote:
A 12v drill can have "exactly" the same power a 24v drill. That is not
a problem. To have them last the same amount of time in drilling, the
12v drill will need a bigger battery in A/hrs.

This adds cost as battery cells are expensive and are the main cost of a
drill.

So, as batteries are expensive compared to knocking out motors en-mass,
they go for larger voltage motors and then the batteries do not have to
be as big (or as heavy, which is major point). They are balancing one
against the other to keeps costs down. That is using the same type of
battery of course, say Ni-Cads.

You

Eff off as you are a plantpot.

dennis@home wrote:


"John Rumm" wrote in message
...
The Medway Handyman wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it
says re cordless tools;

There are some other gems of bull dodo on that page:

"Just think about your car's gas tank: the bigger it is, the less you
have to stop at gas stations."

"Most people think the higher the voltage, the more powerful the
machine is. This is only partially true. If you do the math of
combining voltage with Ah, you may be surprised. Believe it or not, a
12 V drill with 2Ah battery has the same power as a 24 V drill with
1Ah battery."

Is that true?

No. The first bit is ok, however the use of the word "power" in the
last sentence is definitely wrong.

The product of voltage and cell capacity gives a figure for overall
energy stored. So you could say that all other factors being equal the
12V tool could achieve the same amount of work as the 24V tool.
However power relates to the rate of doing the work. So with otherwise
equal tools the 24V will be able to deliver that work in less time.

If everything is "otherwise equal" they will perform identically.

I was talking in terms of quality of cells, drill gearbox, speed control
etc. Not suggesting the motor will draw the same current.

The 12V motor needs to deliver the same amps x turns as the 24V motor to
give the same "power".

I don't follow that. If the 12V tool were delivering the same amount of
mechanical work - same number of turns against the same rotational
resistance, then the output power would indeed be the same, however that
would also broadly suggest that the input power will be similar for
both, which would result in the 12V drawing twice the current.


At practical levels there is unlikely to be much difference between two
drills aimed at the same sector.

Are you suggesting there is little difference between say a 12V Makita
combi and the 18V version?

Just look at the new Lithium stuff its 10.8V but performs as well as the
18V if not better.

The range of voltages seems much the same - lots of 18 and 24V LiIon
stuff about. The 10.8V seems to be reserved for the smaller tools.

So as Dave's reply to EricP nicely demonstrates, The cheap 24V tool
with crap batteries, poorly toleranced gearbox, cheap motor, and rough
speed controller (no offence Dave!) may be equalled in performance by
a high quality tool of half the voltage. What is more the 12V tool
will probably be smaller and lighter into the bargain.

The size advantage should be in the 24V tools favor.

If you were building them to deliver the same power, then yes. In
reality you are going to expect more power from the higher voltage tool.

The copper can be thinner so the motor smaller than the 12V one.
But you will never know as the professional 24V tools are all aimed at
bigger jobs.
And the cheap 24V tools are aimed at the budget market and built down to
a price.

down to a price and up in size usually.



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Doctor Drivel wrote:
"Bob Mannix" wrote in message
...
"Doctor Drivel" wrote in message
...
A 12v motor can give the same power as 24v motor.
The battery size (energy stored) makes it go longer.

Two drills one 12v one 24v, giving the same power.
Both have a 2Ahr battery

The 24v motor drill will last longer.

To users, the convention fior users is that the higher the voltage
the more powerful the drill. Makers market it that way for their
understanding. In general a 24v in the current market will ne more
powerful.

A red letter day!

I've used French letters, not red ones.

What a shame your dad didn't...


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk

In message , Owain
writes
The Medway Handyman wrote:
Doctor Drivel wrote:
I've used French letters, not red ones.
What a shame your dad didn't...

Maybe he did, but they leaked

Like father, like son, eh ?

--
geoff

"John Rumm" wrote in message
news
dennis@home wrote:


"John Rumm" wrote in message
...
The Medway Handyman wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says
re cordless tools;

There are some other gems of bull dodo on that page:

"Just think about your car's gas tank: the bigger it is, the less you
have to stop at gas stations."

"Most people think the higher the voltage, the more powerful the
machine is. This is only partially true. If you do the math of
combining voltage with Ah, you may be surprised. Believe it or not, a
12 V drill with 2Ah battery has the same power as a 24 V drill with 1Ah
battery."

Is that true?

No. The first bit is ok, however the use of the word "power" in the last
sentence is definitely wrong.

The product of voltage and cell capacity gives a figure for overall
energy stored. So you could say that all other factors being equal the
12V tool could achieve the same amount of work as the 24V tool. However
power relates to the rate of doing the work. So with otherwise equal
tools the 24V will be able to deliver that work in less time.

If everything is "otherwise equal" they will perform identically.

I was talking in terms of quality of cells, drill gearbox, speed control
etc. Not suggesting the motor will draw the same current.

The 12V motor needs to deliver the same amps x turns as the 24V motor to
give the same "power".

I don't follow that. If the 12V tool were delivering the same amount of
mechanical work - same number of turns against the same rotational
resistance, then the output power would indeed be the same, however that
would also broadly suggest that the input power will be similar for both,
which would result in the 12V drawing twice the current.

Yes, that's why it needs twice the battery capacity to last as long.
It also means it needs thicker wire as well as more turns.
So the motor will be bigger and more expensive than a 24V motor.

At practical levels there is unlikely to be much difference between two
drills aimed at the same sector.

Are you suggesting there is little difference between say a 12V Makita
combi and the 18V version?

Are they both aimed at the same jobs?
If so there is little difference.
However I expect the 18V ones to be bigger in size and price.

The Medway Handyman wrote:
On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?


No.

The fact of the matter is that the only cell usable a few years ago was
the NiCd Sub C of about an ampere hour capacity. They couldn't really do
more than about 25A, so if you wanted more power you stuffed in more o them.

Hence teh more powerful drills had to use more of them.

However what determines the power with modern cells, is the motor - the
cells will do 50-70A or good ones will, and capacities are pushing 4Ah.

EricP wrote:
On Wed, 12 Nov 2008 20:41:27 GMT, "The Medway Handyman"
wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it says re
cordless tools;


"Most people think the higher the voltage, the more powerful the machine is.
This is only partially true. If you do the math of combining voltage with
Ah, you may be surprised. Believe it or not, a 12 V drill with 2Ah battery
has the same power as a 24 V drill with 1Ah battery."

Is that true?

Not really. It's a matter of torque. A 24v drill with decent gearing
has far more than a 12v even with decent gearing.

More electrical pressure you could consider it as.

Utter and complete bollox.

Its totally down to the way the motor is wound.

You can wind the same motor to do the same power RPM and torque on 12v
or 24v. At twice the current.

John Rumm wrote:
dennis@home wrote:


"John Rumm" wrote in message
...
The Medway Handyman wrote:

On the Worx website http://www.worxtools.com/Technologies.aspx it
says re cordless tools;

There are some other gems of bull dodo on that page:

"Just think about your car's gas tank: the bigger it is, the less you
have to stop at gas stations."

"Most people think the higher the voltage, the more powerful the
machine is. This is only partially true. If you do the math of
combining voltage with Ah, you may be surprised. Believe it or not,
a 12 V drill with 2Ah battery has the same power as a 24 V drill
with 1Ah battery."

Is that true?

No. The first bit is ok, however the use of the word "power" in the
last sentence is definitely wrong.

The product of voltage and cell capacity gives a figure for overall
energy stored. So you could say that all other factors being equal
the 12V tool could achieve the same amount of work as the 24V tool.
However power relates to the rate of doing the work. So with
otherwise equal tools the 24V will be able to deliver that work in
less time.

If everything is "otherwise equal" they will perform identically.

I was talking in terms of quality of cells, drill gearbox, speed control
etc. Not suggesting the motor will draw the same current.

The 12V motor needs to deliver the same amps x turns as the 24V motor
to give the same "power".

I don't follow that. If the 12V tool were delivering the same amount of
mechanical work - same number of turns against the same rotational
resistance, then the output power would indeed be the same, however that
would also broadly suggest that the input power will be similar for
both, which would result in the 12V drawing twice the current.



Got it in one.

At practical levels there is unlikely to be much difference between
two drills aimed at the same sector.

Are you suggesting there is little difference between say a 12V Makita
combi and the 18V version?


Who knows? the voltage is a useless guide to power and quality.


Just look at the new Lithium stuff its 10.8V but performs as well as
the 18V if not better.

The range of voltages seems much the same - lots of 18 and 24V LiIon
stuff about. The 10.8V seems to be reserved for the smaller tools.

So as Dave's reply to EricP nicely demonstrates, The cheap 24V tool
with crap batteries, poorly toleranced gearbox, cheap motor, and
rough speed controller (no offence Dave!) may be equalled in
performance by a high quality tool of half the voltage. What is more
the 12V tool will probably be smaller and lighter into the bargain.

The size advantage should be in the 24V tools favor.

If you were building them to deliver the same power, then yes. In
reality you are going to expect more power from the higher voltage tool.

The copper can be thinner so the motor smaller than the 12V one.

More rubbish.

The power from a motor is roughly dictated by the mass of the thing, and
its efficiency.

Gong up in voltage means more turns of thinner wre,for e same
efficiency. It ends up identical.

"Owain" wrote in message
...
The Medway Handyman wrote:
Doctor Drivel wrote:
I've used French letters, not red ones.
What a shame your dad didn't...

Maybe he did, but they leaked

Wow! A Jocko and cowboy dumbo from Kent.

dennis@home wrote:

I don't follow that. If the 12V tool were delivering the same amount
of mechanical work - same number of turns against the same rotational
resistance, then the output power would indeed be the same, however
that would also broadly suggest that the input power will be similar
for both, which would result in the 12V drawing twice the current.

Yes, that's why it needs twice the battery capacity to last as long.
It also means it needs thicker wire as well as more turns.
So the motor will be bigger and more expensive than a 24V motor.

Ah, sorry, you meant turns as in the motor windings rather than
revolutions of the motor....

Are you suggesting there is little difference between say a 12V Makita
combi and the 18V version?

Are they both aimed at the same jobs?

The low end will do a subset of the jobs the high end will do. So I
guess you can take that as yes or no.

If so there is little difference.

It seems quite marked in handling...

However I expect the 18V ones to be bigger in size and price.

Indeed.

--
Cheers,

John.

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"The Natural Philosopher" wrote in message
...

The copper can be thinner so the motor smaller than the 12V one.

More rubbish.




For the same output you need turns x amps.
If you have less turns you need more amps.
A 12V battery will not be able to put as much current into the turns unless
the wire is thicker.
So for the same number of turns a 12V motor of the same performance will be
bigger, use more copper and cost more.