Just curious… Why do you want to limit the current?

A device will only take what current it needs from a battery. If your battery can supply 100A and your device only needs 100mA, the device only takes 0.1A from the battery. No current limiting is required.

If you want to protect the battery or device in the event of a failure of either of them, then what you want is a fuse, as @ronsimpson has suggested.

i am also interested in limiting the power that my power station draws from my car. it can do 600w but i only want it to draw 60w while underway. i also charge other batteries from alternator that taxes it. a ready made device would be awesome

Moderator edit: New thread created from this.

 

You don't have to do anything. The load will only take what it needs.
If you want protection from overheating, use a suitable fuse which will blow when a given current is exceeded.
There is also such a thing as a resettable fuse also known as a polyfuse or PPTC.

 

You need a CC circuit to limit current (power).
Usually current sense feedback into opamp where output of opamp drives a transistor that controls the current.

 

interested in limiting the power that my power station draws from my car. it can do 600w but i only want it to draw 60w while underway.

Forgive MY ignorance but what is the "power station" you're talking about? If you're talking about an inverter that takes 12VDC and converts it to 120VDC @ 600W limiting the current from the battery/alternator probably won't help anything.

On the understanding that 600W is what's available, a circuit will only draw what it needs. If you have an 85W battery charger plugged in then it will only draw 85W from the inverter. Limiting the ability of the inverter will likely result in poor performance. Inverters are already known to be somewhat inefficient. While the good ones can be 95% efficient it's not hard to find one that is 80% or even less. Depends on how much you spend on it. Going from 600W to 60W means you're asking to limit it to 10% of what it was designed to run on. Being limited like that may lead to the inverter overheating and possibly failing if you try to draw more power from it than is available.

Of course, I may be wrong. Happens from time to time.

 

There are two ways to limit power transfer, which are either to reduce the voltage, or to switch off the connection. An electronic overload disconnect seems like what your application requires. Reducing the voltage very much will often prevent correct operation. The other option is for an indicator to remind you of the actual current when it exceeds some limit amount.

 

And now, additionally, I am GUESSING that "Power Station" is a fancy marketing name for a power inverter to supply 120 volts AC from a 12 volt DC source. What you need to understand is that most of those inverters require some small amount of DC power to operate without any load connected, and the when a load is connected they require additional power to supply the AC power to the load. That conversion is often at about 85% efficiency. So the only way to keep the power draw low is to keep the AC power load low.
There are, however, some older style inverters that draw a large amount of power whenever they are switched on. I suggest that they can often yield some useful salvaged parts.
Or possibly dedicated to a single load that will use most of their capability, and not used for anything else.

 

Inverters are already known to be somewhat inefficient. While the good ones can be 95% efficient it's not hard to find one that is 80% or even less.

And now, additionally, I am GUESSING that "Power Station" is a fancy marketing name for a power inverter to supply 120 volts AC from a 12 volt DC source. What you need to understand is that most of those inverters require some small amount of DC power to operate without any load connected, and the when a load is connected they require additional power to supply the AC power to the load. That conversion is often at about 85% efficiency. So the only way to keep the power draw low is to keep the AC power load low.

OK, some more in-depth comments regarding how much power an inverter may draw. But - - - ? ? ?

 

One more consideration about the operation of "regulated" inverters. I have two of them, one rated at 600 watts and one rated at 1200 watts. I ran them both, one at a time, from my metered power supply, each using a 100watt incandescent light bulb as the load. I varied the supply voltage between 13 volts and 11 volts, and I discovered that while the bulb brightness did not seem to change, the DC current increased as I reduced the voltage.
What this tells me is that reducing the voltage to the inverter will increase the current drawn from the battery, so the current will be reduced a small amount when you run the engine and the alternator increses the system voltage a bit.