Amps And AMP Hours?

[Cougar]

I need some expert advise on amps and AMH Rating..

 

I want to use a winch thats says not to use a battery with less

12 AMHTo run it.. Now I have the Pyramid regulated power supply

that has a constant 12 AMP Rating. So will this run that Winch?

Hope this makes since *lol*

Thanks,

Jeff

[GG54172]

Sure, that makes a lot of sense.

 

Let's start with the battery. Batteries are rated in amp hours. A 12 volt lead acid battery that is fully charged, rated at 10 amp hours, will supply 10 amps at approximately 12.5 volts (125 watts) for one hour. At the end of the hour, the battery may have some life life, but will need to be recharged.

 

A 12 volt lead acid battery, rated at 20 amp hours, will supply 20 amps of current at approximately 12.5 volts (250 watts) for one hour. The same battery could supply 10 amps of current at approximately 12.5 volts (125 watts) for two hours, before needing a recharge. Or, it could supply 1 amp of current at 12.5 volts (12.5 watts) for 20 hours. That same battery should be able to supply 40 amps of current at 12.5 volts (500 watts) for 1/2 hour.

 

No this is an idealized case. Could a 20 amp hour battery supply 1200 amps at 12 volts (14,400 watts) for one minute? Not likely, and it would be very dangerous to attempt such a thing. The battery would likely explode.

 

So car starter batteries have an additional rating, called Cold Cranking Amps (CCA) A battery can provide the CCA current for a few seconds. Even then, I would want some guarding over the battery and face protection.

 

 

 

Now, your regulated power supply is rated at 12 amps continuously. I assume that is at 12 volts (144 watts). Can the power supply run the winch? I do not have enough information. A DC electric motor (likely the type in your winch) acts like a near dead short when it is not spinning. The intial current draw when you flip the switch on a DC electric motor is very high. The required current to spin the DC motor goes down very quickly (less than a 1/4 of a second) as the rotational speed increases. Batteries are large in mass, and can absorb very short duration high heat load safely.

 

Now, your DC power supply probably has IC circuits inside. And the circuits are very small, so the internal components can get hot very quickly. If the power supply is new enough, it will have an internal safety feature to shut down high current.

 

I would expect that your DC power supply can run the winch so long as there is no load. (the winch isn't pulling anything)

 

I assume that you are trying to pull a car onto a trailer?

 

It is possible that you winch will draw more than 12 amps when you actually try to pull a car onto the trailer. I would not try to use the power supply to pull a car onto the trailer.

 

Here is what I did for my trailer winch. Go to the hardware store and buy a household extension cord that is long enough to reach from the winch to the battery of your truck/car. Cut the two ends off of the extension cord. On one end, wire the cord to your winch. On the other end, wire two decent sized alligator clips big enough to bite onto the positive and negative lugs of your car battery. When you get your trailer to where ever your new project is, just pop opn the hood and use the battery that you already have.

 

Let me know if you have more questions.

 

Somethings that would help me help you:

 

Does the winch have a maximum current (amp) or power (watt) rating listed on it?

Does the power supply have a maximum power rating?

How do you plan to use the winch?

[GG54172]

Hey! we don't live far from each other. I would be happy to come down and help you. Supposed to snow like crazy today. Maybe later this week?

[Cougar]

*LOL* Yeah Damn Snow.. How funny you do live sorrta

close , lemme get some more info my friend.

And I will email it to you. THANKS!

Jeff

[Cougar]

Rated line pull2000lb(907kg)Motor12V DC, 0.8HPGear ratio136:1Wire rope3/16 x 45 ftDrum Diameter1.25""(31.75mm)Drum Length2.9""(74mm)Line Pull(lbs./kg)Line Speed FPM(m/min)Motor(Amps) 027ft(8.3m)151000(454)24ft(7.3m)601500(680)16ft(4.9m)1002000(907)9.5ft(2.8m)130

[GG54172]

Rated line pull2000lb(907kg)Motor12V DC, 0.8HPGear ratio136:1Wire rope3/16 x 45 ftDrum Diameter1.25""(31.75mm)Drum Length2.9""(74mm)Line Pull(lbs./kg)Line Speed FPM(m/min)Motor(Amps) 027ft(8.3m)151000(454)24ft(7.3m)601500(680)16ft(4.9m)1002000(907)9.5ft(2.8m)130

 

Ok, so the motor of the winch is rated at 0.8Hp. 0.8Hp equals about 600watts. At 12 volts you are talking 50amps of current. It also looks like the motor is rated for a short term current of 130 amps. (1500 watts)

 

If your power supply is only rated for 12 volts and 12 amps (144 watts), I would not attempt to move a load with the winch powered by the DC power supply.

 

Is this for a trailer?

[Cougar]

Just sent you an email.

[Monty]

LIke GG said...running direct from the battery is your best choice.

[Cougar]

yeah I guess I could get a Battery and keep a tender on it all the time.

a cheap walmart battery maybe. with higher the 12 AMPh on it.

[Monty]

If you're gonna mount the battery on a trailer or something that doesn't keep it charged, I would suggest getting a deep-cycle marine battery. You can get one for a decent price at Wallyworld.

[Cougar]

Good Idea, thanks Monty