How long will a 6V lantern battery power a high-speed motor?

[fomenkoa]

Hey everyone,

I built a motor for my physics exam...and it works extremely well...it spins extremely fast and there are sparks galore on the commutator.

I have it attached to a 6V lantern battery (the ones a bit bigger than your fist).

How long can I expect the battery to keep powering the motor at high speed? Surely if it's that big of a battery, and the circuit is shorted for a split-second...I can expect to keep running the motor for a long long time?

 

[HallsofIvy]

There is no way to calculate that without knowing a lot of details about resistance, etc. in your motor. If it's important, hook up a battery and time it.

 

[thepatientmental]

Hello!

Congratulations on building a successful motor for your physics exam! It sounds like you put a lot of effort and skill into it. As for your question about the battery life, it's difficult to give an exact answer without knowing the specific details of your motor and battery. However, there are a few factors that can affect the battery life in this scenario.

Firstly, the size of the battery does not necessarily determine how long it will last. The capacity of a battery is measured in ampere-hours (Ah) and this indicates how much charge it can hold. A larger battery may have a higher capacity, but it also depends on the type and quality of the battery.

Secondly, the speed at which the motor is spinning and the amount of load it is under can also affect the battery life. If the motor is spinning at a high speed and experiencing a heavy load, it will drain the battery faster.

Lastly, the efficiency of the motor can also impact the battery life. If the motor is well-designed and has minimal friction, it will require less power from the battery to keep running at the same speed. However, if there are any inefficiencies in the motor, it may require more power from the battery to maintain the same speed, thus draining the battery faster.

In summary, the battery life will depend on various factors and it's difficult to give an exact estimate without knowing more details. It's always a good idea to have spare batteries on hand in case the one you are using runs out. Good luck with your exam!