I have a DC 12V to AC 115V, 300W inverter. Designed for plugging into a car’s cigarette lighter and giving you AC current to power most any sort of appliance.
The problem is the plug that goes into the car’s cigarette lighter socket is broken. My car has a second DC outlet in the back, but the ring on the socket kind of sucks, and the plug got stuck in there; only way to remove the inverter plug was to break it.
So I just got a replacement plug that I was going to attach to my inverter cable. The only concern: the plug is rated at 10A, but the inverter has a 30A fuse.
Am I risking disaster here? Or does it not matter?
The answer will probably depend on how much power the AC device needs.
If it is pretty low power, like under a 100 watts (and most things that don’t heat or have big motors are under 100W), you’ll likely be OK.
A vehicle’s fuse for the lighter is often something like 20A for reference.
Nope. Not at all. You’ll blow the fuse in the plug you bought before you blow the fuse in the inverter. Your problem seems to be how to get the plug to power the inverter. Preferably without melting something. If you can give me an idea of what you’re actually trying to do, I might have a suggestion or two.
The other question is whether the circuit at the back of the car can supply anything like 30A. It is probably not wired for that sort of current and the fuse in the car for the outlet may well be rated at a lot lower lower than 30A, likely less than the dashboard mounted outlet. The voltage drop down the length of a car with the usual cable used in cars at 30A is not small, and you may find yourself in all sorts of trouble getting it all to work. As jnglmassiv points out, if the item you power is pulling less than 300W you are probably going to be OK, but full power is going to translate to a lot of current. Look at the insane extremes car audio enthusiasts go to to manage systems with not a great deal more power draw.
FWIW, here’s the inverter. There are two 3-prong plugs on the side opposite the green 30A fuse/power switch.
That 10A plug (the bottom picture) is the new addition. I cut off the old, cracked one and wired the new one onto the cord that’s now sticking out of it.
I don’t envision running a space heater on this thing, or even major power tools. I was figuring more like laptop, cell phones, maybe a portable boombox.
Remember, if you have an inverter that’s rated at 300W, then with a 12 volt battery, full power would be 300 watts divided by 12 volts = 25 amps being pulled from the battery. Your 10A plug might get a bit hot under that circumstance.
So the cord is the original inverter cord? Did the new plug have a cord you removed, or did it not come with a cord at all? If the plug had a cord, the 10A limit could have been based on that cord, not on the plug itself.
It’ll be fine for just those things. They don’t draw anywhere near even 100 watts. All at the same time, they might draw that much, though. From the pictures, it looks like you should be able to use the thing for the full 300 watts if you solder the wires directly to the contacts inside the plug. I can’t be sure of that, however, unless you can open up the plug and post a picture of what’s inside.
You’re planning to run an 18 to 20 volt laptop or a 5 volt phone directly from a 12 volt car power socket? You need another :smack: to realize that the voltage matters.
Not exactly related to the question but might be helpful. Be aware that there are two sizes of DC plugs out there. One is a little larger than the other so you need the right one for your application. That may explain the problem you had with the socket.
You need to wire it to the battery or fuse block. Most car makers only put sockets rated for 15-20 amps at most. This is why they are all melted and give problems. To do it correctly use a minimum of 10 awg and go to the fuse block
He didn’t say to plug it right into the battery. He’d still have to step the voltage up or down, but that’s probably cheaper and more efficient than DC/AC/DC conversion.
