Does ESC take as many volts as it needs?

[Emm2849]

So I have a 12-volt 5-amp motor that I'm using for a ROV. I was just wondering if I could hook the motor up to a 20-volt battery and if the ESC would still be drawing the same volts or it would be feeding the ESC to many volts.

 

[Exc3l]

No, you can't do that. Max volts is the amount of voltage it can take from a source. I am pretty sure higher end ESC's have a saftey cut off to where they dont boot if there is too much voltage.

EDITED. Misunderstood

 

[Emm2849]

The ESC that I have can handle up to 24 volts

 

[bill_delong]

This is an ambiguous question because current is a variable and all ESC's will have some loss of efficiency depending on the quality of the ESC. You would need to hook up a voltmeter to your ESC to gather your own data.

I've done something similar in the following video with an 8.4V battery input, but the motor only drew 5V at WOT presumably the max load rating for the crawler motor:

 

[Exc3l]

The ESC that I have can handle up to 24 volts

Oh I thought it was a 12v ESC.

Okay so this would work. Are you going to be using Lipo's? I would just watch temps because the thing that kills electronics is heat. Watch the motor temp. I would just get an ESC designed for what it is you are doing. 20v on a 12v motor is a bit much but people do it for speed running. It will work

 

[Emm2849]

I'm using the 20 volt battery just for testing

 

[Exc3l]

I want to test this but I dont want to break the motor by accident

You arent going to "break" it right away. Is it a brushed or brushless motor. While you are running you would need a way to check temps. Or just get a smaller battery. What kind of batteries are you using right now?

 

[Emm2849]

I am using a 20-volt Dewalt battery, this is just for testing though. I am getting 2 2s lipos connected in series to power the motor. Its a Brushed motor

 

[Exc3l]

I am using a 20-volt Dewalt battery, this is just for testing though. I am getting 2 2s lipos connected in parallel to power the motor. Its a Brushed motor

I would just test for a little bit keeping check of temps. Brushed motors wear down fast because they arc more at higher volts causing more heat in the process. You can test and make sure everything works. Are you planning on running on the 2 lipos? That motor will barely handle that voltage.

 

[Emm2849]

Oh sorry, I meant the 2 lipos connected in series to make 14.8 volts

 

[Exc3l]

Oh sorry, I meant the 2 lipos connected in series to make 14.8 volts

Those Lipo's charged up is going to be too much.
4.20x4= 16.8

3s would be ideal for this

 

[Lukedavis]

Oh I thought it was a 12v ESC.

Okay so this would work. Are you going to be using Lipo's? I would just watch temps because the thing that kills electronics is heat. Watch the motor temp. I would just get an ESC designed for what it is you are doing. 20v on a 12v motor is a bit much but people do it for speed running. It will work

It’s for a science fair project. It is a submarine and will be going under water. It does use lipos and will be running on 4s lipos.
The reason that I know is because I helped solder the connections for him.

Oh sorry, I meant the 2 lipos connected in series to make 14.8 volts

Check your replies on the introduction thread lol

 

[Greywolf74]

If the motor is only rated for 12v then running it on 20V or a fully charged 4S LiPo (16.8v) then your asking for trouble. If it doesn't run WOT for sustained periods of time maybe you'll be ok with it but you're operating outside of tolerances so theres no telling. As others have mentioned watch temps and during testing make sure you're monitoring amp draw by the motor if possible to make sure you arent exceeding that 5A max.

 

[Jerold]

For clarification the battery provides voltage and the ESC draws Amps.

Meaning there is a valid input voltage range, something like 2S-4S for every ESC. Using any voltage outside that range is not characterized and we don't know what will happen. It might work fine or it might burst into flames, I dunno, but it's not covered by any warranty and you do it at your own risk.

The ESC draws current and will use what is available as needed. Think of this as drinking from a straw. The glass you are drinking from doesn't push the liquid into the straw. You can suck a little bit or you can suck a lot. At some point you reach max suction for the straw/liquid setup and you don't get any more.

This is a very brief description and there area bunch more details in this.

 

[Emm2849]

Ok, Thankyou

 

[thatcraig]

Good luck with your science fair project!

 

[Lumikko]

Electric components ”take what they need” (or ”draw”) when it comes to current i.e. Amps. This can be restricted by the power source on purpose or if it’s simply unable to provide enough Amperes.

Voltage is what the power source supplies. The component or circuit can handle it only if it’s within the specified range.

Generally, a simple brushed motor can handle significantly higher voltages than specified. It’ll just spin faster and arc a bit more at the commutator but excess voltage itself doesn’t make it run hot.

When you load the motor and it draws more current, we start observing heat. Higher RPM should be compensated with reduced load to stay within a reasonable amount of work the motor is expected to do for a given time, i.e. power (Watts).

This is why we switch to a smaller pinion when going from a 2S battery to a 3S battery: the motor spins at a higher RPM so we make the load lighter to keep temps in check. (The same applies to motors with a smaller amount of turns i.e. higher KV value.)