starter motor

[wes]

Hi guys, I was wanting to use a 12 volt starter motor to spin an alternator,geared of course,but not sure how long a starter would run continuously for....Could anyone help with this...Wes.

[m1lky]

Why?

A starter draws a very large amount of current, generally more than the alternator generates.

I would think running for an extended period of time (if you didn't just flatten battery) the starter would probably get very hot quite quickly (miniutes)

[wamboin23]

^^ correct.

while a starter is only going to draw the same amount of current as a similar sized motor, a starter is not designed to be run anymore than maybe 10 seconds at a time. it is quite common to see starters fail soon after people have been cranking cars for a long time due to faults.

They will heat up quickly because there will be no airflow etc.

Possibly an old generator would be better for what you need. With direct battery power and the field current they will spin just like a motor, and have a fan etc for drawing air over the hot parts.

[wes]

Thanks guys,,,,,,,Just had some more input,how would the electric motor from a vn vp fan go.. (really want to see if i can make this work.

[wamboin23]

what are you trying to do?

[Dr HaxZaw]

Are you looking to make a home made battery charger?

[wes]

want to use 4 components, (1) heavy duty 12v electric motor to spin an (2) alternator to keep charged the (3) battery that runs the 12v motor and (4)power inverter to run 240 volt stuff for camping.

[wes]

want to use 4 components, (1) heavy duty 12v electric motor to spin an (2) alternator to keep charged the (3) battery that runs the 12v motor and (4)power inverter to run 240 volt stuff for camping...........So in a nutshell it uses itself to run itself.

[wamboin23]

it cannot work.

you cannot create energy, it has to be changed from another form. the fact that the motor creates heat means that you are loosing energy.

you need 101%+ efficiency, which just isn't possible at this time. the battery will eventually go flat, quicker infact than without this setup

[m1lky]

Potentially you could get this to work with say a lawn mower motor or maybe scooter engine? Would be bloody loud though.

[axemurderer101]

How about using a bike to turn the alternator lol

[Ghost]

Or actually buying a generator

[wes]

Yeh I could take my generator camping,to run the beer fridge,etc..but I can see some people who would not appreciate the noise!!!!!!! So that is why I wanted to see if I could make this thing work,,,,,yeh I know!!!!!! if I was made of money I could go buy shit loads of car batterys and 12volt fridge,lights etc,but until then........

[Ghost]

Well I think there are solar battery chargers for cars

[Dr HaxZaw]

Make a big arse muffler for the generator... it might lose a bit of power but you could definelty make it quiet