Originally Posted by dogwood36322
Why not use a regular 110 extension cord and modify it with the proper plugins for our use? put a regular 110 plug on the end of your compressor and an adapter for the other end of the extension crd.
The issue is that will still have a high "I squared R loss
". The issue is while 110 moves more power it does so with less current by using a higher voltage. This is why you need to use heavy gauge wire on an inverter, if you do not most inverters will see a low voltage condition due to the voltage drop across the feed lines unless the inverter is a fairly small one. Additionally you will lose a lot of power in the form of waste heat. The wires will just turn into toaster elements.
Remember also the longer the cable run, the higher the resistance. Resistance isn't just a function of cross sectional area but also length. The longer your extension cord the more you're supposed to derate for the current capacity for loading. This is one of the reasons why stacking two extension cords together is such a big deal. At the end of the cord you're no longer seeing 110V but instead a lower and depending on the tool it will draw more current to make up for the sagging voltage.
It is likely that the compressor does not run 25
amps continuous as that would be almost 300W, however it also depends on the size, capability, efficiency, and loading of the compressor. There is also the starting inrush, however fuses and line ratings are based on continuous load and can even handle reasonable inrush currents. 10 or 15 amps should be plenty for most, especially if it runs out off the cigarette adapter plugs. Those are nominally rated for 10 or 15 Amps unless you've installed something special. That said, looking around I'm also seeing some bigger compressors that are up to 45A
The joke at a previous place I worked was, anything can work as a fuse, including transmission lines, once. Additionally, especially on something like this, your equipment will run better with a higher efficiency the closer you can put the power to the compressor. This is the downside to 12V power, you have to move a lot of current to deliver the power.
My order of options would be, out of convenience and expediency:
- Replace the battery.
- Get a jump pack for use with the compressor.
- Build a jump pack for use with the compressor.
- Use an extension cord.
You can always attempt the last item if you have no choice and need it now, worst that can happen is you blow the fuse.
*Side note* I did just think of a trick you could do with the 110 cable though. You could use a boost buck converter
on one end and a DC switching power supply
to bring it back down on the other end. You could run 48+V in the middle then dropping your current losses in the middle. We used that trick during a HAM field day exercise once
to cut the losses from out battery bank outside into the trailer. I am now thinking of ways to leverage that trick in my new trailer...