Will 2 AA turn a motor faster then 2 AAA?

Thread Starter

stanman11

Joined Nov 23, 2010
228
I got an rc car at a garage sale for a buck. its a wired remote with 2AAA but it doesnt really want to move much so I was thinking upping to a bigger batteries.
will this work?
 

Georacer

Joined Nov 25, 2009
5,182
I think it's more likely that you 'll burn its circuitry, if it's digital.

Try to clean its axis from the hair wounded behind the wheel and turn the motor axis with your hand to see if it moves freely without friction. Resistance would be a sign of dirt.
 

nerdegutta

Joined Dec 15, 2009
2,684
If you change from 2 AAA to 2 AA, the voltage will stay the same, but it will last longer.

Compare this AAA datasheet to this AA datasheet.

Please correct me if I'm wrong...:)
 

SgtWookie

Joined Jul 17, 2007
22,230
There should only be a slight, if any, difference initially - the big difference will be the run time due to the difference in mAh ratings. I suggest that out try doing some.checking with an odometer first though.
 

spinnaker

Joined Oct 29, 2009
7,830
I got an rc car at a garage sale for a buck. its a wired remote with 2AAA but it doesnt really want to move much so I was thinking upping to a bigger batteries.
will this work?
Check the linkage in the gears. Most likely is is gummed up with all sorts of dirt and debris.

Or it could simply be a bad motor.
 

Audioguru

Joined Dec 20, 2007
11,248
Cheap little RC airplanes use tiny brushed motors (made to open and close a CD tray). The brushes and commutators wear out after a few hours of running which reduces the power and sometimes they will not start unless the motor shaft is turned a little.
I have about 8 worn out motors.

My more expensive little RC airplanes use brushless motors that keep running and running and running and running and running at full power forever.
 

tshuck

Joined Oct 18, 2012
3,534
The only way you should see a difference, aside from longer life, would be at startup, assuming the 2 AAA batteries could not supply the proper current for the motor stall.
 

tshuck

Joined Oct 18, 2012
3,534
...to answer your question, unless the design was horrid and they didn't spec the motors properly, you should see no difference in motor speed after startup.
 

Thread Starter

stanman11

Joined Nov 23, 2010
228
Ok, well that answeres my questions.
It doesnt have any circuitry, the Controller is a spring loaded joystick and the wires gor straight to the motor from there.
and its clean from hair its just a POS

Thinking about putting a 3.6v Cell battery under the car body with a charging inlet and making it in to a stomper. just turn on and let it go by itself?
 

Thread Starter

stanman11

Joined Nov 23, 2010
228
Ok guys I got a switch and a charging unit mounted in this little car.
The car takes 2 AA 1.5 normaly. I put in it a 3.7v Lion battery but the thing is way to strong and I can smell electrical burning.
When I connect a 100ohm resistor it wont turn the motor
any suggestions?
 

Audioguru

Joined Dec 20, 2007
11,248
Why do you think adding 100 ohms in series with the motor will slow it a little?
The value of the resistor depends on the operating current of the motor. Maybe you need only 10 ohms (or less) to reduce the current so it is the same as if the motor is powered from 3.0V.
But you burnt something so maybe now the motor is ruined.
 

Thread Starter

stanman11

Joined Nov 23, 2010
228
motor is still good. thing is way to fast. I dont get how an extra 0.6v made it so fast when 3v barely made it move
 

Audioguru

Joined Dec 20, 2007
11,248
A "3.7V" Lithium rechargeable cell is 4.2V when fully charged and it can supply LOTS of current without its voltage dropping.
Little AAA alkaline cells do not produce much current, if loaded then their voltage drops.
AA alkaline cells can supply twice as much current as AAA cells but not nearly as much as a rechargeable Lithium battery cell.

You cannot do much without knowing how much current the motor is drawing.
 

THE_RB

Joined Feb 11, 2008
5,438
You could use a diode to drop the 3.6v to roughly 3.0v.

A 3 amp diode would be advisiable, I think 1N5803 or 1N5804 is the common part number?
 
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