HELP!! How much torque??

[Bingobelle]

How come that 36 v does not produce more power compare to 18 v if the same amount of current is drawn from the battery?

For example : p = u* I  P= power      u = voltage      I = current

Lets say a 18 v driver take 1 A. That will be 18*1= 18 w in power.

A 36 v driver take 1 A, that will be 36*1= 36 w in power.

So with the same amount of current taken from the battery a 36 v tool should be able to produce the double amount of power.

In my world the bennefit with higher voltage is that you need less current from the battery and therefore you will have more runtime at same kind of load. If you draw 10 A from a 36 voltage machine the motor will produce 360 w minus some effecinecy losses in transmission and motor. A 18 voltage tool will only produve 180 w if the draw is 10 A from the battery.

The battery is like a tank of energy filled with Ampere hour. For example the new dewalt 4,0 A battery. If a 36 v drill and a 18 v drill is using the same amount of current at a given workload the 36 v drill should be able to do the double amount of work. And if it is designed to handle the same amount of current before shutting down as a 18 v drill it should also be able to be twice as strong as a 18 v drill. 

And also, the amount of current that the machine is taking from the battery is not static at any way. The current draw depends on the workload. A 35 mm spadebit will use more current compare to a 20 mm spadebit ( same kind of wood and force putting down on the drill ). A supersized lag screw will take much more current compare to a tiny small screw. The difference is that the 36 V drill only have to use half the amount of current taken from the battery compare to the 18 v drill.

So, double voltage give double power from motor at a given ampere usage or I´m missing something?

[golden valley const.]

You're only missing that many of the 36v batteries available are lower amp-hours.  Dewalt 36v batteries are 2.2 amp hour.  The new 18v 4.0 amp hour batteries are almost as good and much smaller.

[Bingobelle]

But the new cells must only be 2,0 A hour. They are 5 in serie that gives 18 volt. ( 3,6*5 = 18 V ) and 2 amp each. The 4.0 Amp battery is because it is two "5 pack" connected in pararell.

Anyway, of course you need more cells in serie to have more voltage if you want to keep the amp hours. Or you can still use 10 of the new cells in serie to get 36 v but only 2 amp hour. The tool will only use half the amphour for the same amount of workload but if you need more power but for shorter time you can have it. But of course, if you are going to use that extra power the battery cells will take a bigger beating due to more current drawn from each cells but only if the extra power you demand will be more than twice a much. ( the 36 v tool only use half the current at same workload as 18 v )

Not saying a 36 v tool is better than a 18 v tool but with 36 v you can have a stronger tool. Make a battery pack with 20 cells and you will have 4.0 amphour and 36 volt. cons is a bigger and heavier tool but i guess that goes hand in hand with many things.

Imagine the new cells but with 4.0 Amphour in each cell! that would make a 36 volt batterypack with same size as the 18 v possible. But then again, the tool must be able to take that extra power and heat and probely that means a much bigger tool.

There is always pros and cons I guess.

Sorry for spelling and grammar ( scandinavian )

[JDaugherty]

Question.... On a Hyper Tough 18V cordless drill, what number do i need to set it on for 24 to 28 ft. Lbs. Of torque?