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General Category => General FAQ'S => Topic started by: ScottTENN on February 15, 2018, 09:57:04 PM

Title: Low voltage input with high amperage, will it charge?
Post by: ScottTENN on February 15, 2018, 09:57:04 PM
I have acquired a few large 24VDC permanent magnet motors.  Crazy high torque.  The rating are 24 vdc, 42 amps at 200 rpm.  When I put these on my bench and just connect the positive an negative to a amp meter and start turning the motor the amp reading go high quick.  Higher than the 10a max of my meter.  The fastest I can hand crank it with a 12v 1amp load (led light string) is about 15v.  Makes me wonder if a Classic 150 can take that less then 24v, high amp input and charge a 24v battery setup.

So can a Classic 150 take in a lower voltage than the batteries, but convert the high amp input into usable charge voltage?  Think water wheel application.

Thanks for your thoughts.
Title: Re: Low voltage input with high amperage, will it charge?
Post by: ClassicCrazy on February 15, 2018, 10:04:20 PM
The Classic will only convert voltage down - not up .   

Larry
Title: Re: Low voltage input with high amperage, will it charge?
Post by: boB on February 16, 2018, 08:25:41 PM
Yes, Larry is correct.  The input will need to be higher than the required output voltage.

It will also need to be at least 1/3 higher voltage than the battery and just a couple volts
more as well to start up.

boB

Title: Re: Low voltage input with high amperage, will it charge?
Post by: ScottTENN on February 22, 2018, 10:45:33 PM
I was pretty sure that it would not be able to up the voltage.  A transformer might get me there.  This discussion is only theoretical as I don't have a transformer to use and not keen on burning up my Classic 150.

The motors are 24 Volt DC brush motors.   They came out of some industrial floor scrubbers.  They are the motors that power the brushes that contact the floor.  I'll have to get a picture of the specs.  They are a bit bigger than a large coffee can and weigh 20+ pounds.  Solid.  Lots of copper.  You can't turn the shaft with your bare hand.  There has to be a mechanical advantage to make it turn.
Title: Re: Low voltage input with high amperage, will it charge?
Post by: ClassicCrazy on February 23, 2018, 01:26:48 PM
Quote from: ScottTENN on February 22, 2018, 10:45:33 PM
I was pretty sure that it would not be able to up the voltage.  A transformer might get me there.  This discussion is only theoretical as I don't have a transformer to use and not keen on burning up my Classic 150.

The motors are 24 Volt DC brush motors.   They came out of some industrial floor scrubbers.  They are the motors that power the brushes that contact the floor.  I'll have to get a picture of the specs.  They are a bit bigger than a large coffee can and weigh 20+ pounds.  Solid.  Lots of copper.  You can't turn the shaft with your bare hand.  There has to be a mechanical advantage to make it turn.

What would you ever use to turn it to make power ?

You either would need a lot of wind or lot of water pressure.  I don't believe that kind of motor is suited to either of those uses over the long term or practically .

Larry
Title: Re: Low voltage input with high amperage, will it charge?
Post by: CDN-VT on February 24, 2018, 02:00:56 AM
Quote from: ScottTENN on February 22, 2018, 10:45:33 PM

The motors are 24 Volt DC brush motors.   They came out of some industrial floor scrubbers.  They are the motors that power the brushes that contact the floor.  I'll have to get a picture of the specs.  They are a bit bigger than a large coffee can and weigh 20+ pounds.  Solid.  Lots of copper.  You can't turn the shaft with your bare hand.  There has to be a mechanical advantage to make it turn.
As for your Waterwheel  idea , I don't think those are the motors to use.
Mine will be 3 phase AC alts that have no bumpy resistance to start .
AC high voltage for the length to transfer the AC power a distance and then rectifier it to DC for the Classic to reg the charge .

VT
Title: Re: Low voltage input with high amperage, will it charge?
Post by: Nomad1 on September 07, 2018, 04:50:23 PM
Quote from: ScottTENN on February 15, 2018, 09:57:04 PM
I have acquired a few large 24VDC permanent magnet motors.  Crazy high torque.  The rating are 24 vdc, 42 amps at 200 rpm.  When I put these on my bench and just connect the positive an negative to a amp meter and start turning the motor the amp reading go high quick.  Higher than the 10a max of my meter.  The fastest I can hand crank it with a 12v 1amp load (led light string) is about 15v.  Makes me wonder if a Classic 150 can take that less then 24v, high amp input and charge a 24v battery setup.

So can a Classic 150 take in a lower voltage than the batteries, but convert the high amp input into usable charge voltage?  Think water wheel application.

Thanks for your thoughts.

I don't know why no one wrote it before, but ammeter should never be connected to the power supply directly!

Don't ever try to connect it to positive and negative wires directly! You'll either fry your wires, the motor or the meter device, may be even resulting in fire! Of course, you'll also get completely wrong measures. Find anything to simulate high load (resistor, car electric kettle, some other 24V appliances) and put your amp meter to the break of the line, in series with the load. In some cases the load resistance could be too high resulting in minimal current, so you need to invent something. Strictly speaking, resistance of amp meter is close to zero, so you are mostly short-circuiting your motor.