Fast charging from 120V

[vfx]

This 120 Doubler rig solves a problem and I use it every day.

Not everyone can access a 240V circuit no matter how much they desire. "Fast" is a relative term but I assure you, those that are still forced to 120V sites will take notice.

This device is useful for Tesla owners living, (or visiting) apartment buildings and condos. For road trips it can significantly cut wait times at charge stops.

With 120V at 12 amps I get about 3.5 Miles Per Hour Charge (MPHC) (the Tesla charge manual lists that as a from-empty 70 hour charge) Very slow because the temperature control pumps and fans consistently draw power first.

With 120V and the VDS set to 16 amps I get about 4.8 MPHC, (the Tesla charge manual lists that as a from-empty 36 hour charge) a huge difference.

With the 120Doubler rig at 16 amps, charge time is now 11 MPHC (the Tesla charge manual lists that as a from-empty 18 hour charge) Any increase of amperage from this point show much smaller gains in charge time. With this setup, charging is basically overnight!

It consists of:
A MC240 or Roadster Foundry cable
A Quick 220
Various Adapters (user wired)
Long heavy duty extension cord(s) to find an out of phase 120V circuit. Mine is 130 feet


The image shows the setup outdoors but this is an indoor rated device. Also note the coiled cord shown is an unsafe practice and no power is present in the picture.

[TEG]

How do you tell it to draw no more than 16amps ahead of time?
Do you have to set that on the VDS before plugging the MC240 into the Roadster?

I imagine if you let it try to draw 24amps (MC240 default) it would likely blow both breakers on the two 120V circuits.

[vfx]

The GPS memory overrides the MC240.

That is, at least in this case, the car already knew this site was a 16amp draw from when I only had a MC120V and when I went to a MC240 it stayed there.

[TEG]

OK, so you have to be careful when hooking that "contraption" up in new locations. Is there a way to pre-program the GPS ampacity setting for a new location before you plug it in?

I wonder how many locations the GPS can store?

[vfx]

OK, so you have to be careful when hooking that "contraption" up in new locations. Is there a way to pre-program the GPS ampacity setting for a new location before you plug it in?

I wonder how many locations the GPS can store?

Our list of questions about the GPS knows no end.

I will test the rig at another site this week.

[donauker]

When you open the charge port door on the Roadster the charge screen is shown on the VDS. You can then go in and set the max current for this location before connecting the cable, or you can connect the cable but not slide the switch forward. The car ignores the cable until the switch is closed.

[TEG]

Thanks, Don...

[vfx]

I did test the current setting at another location.

Before hooking up I set the current at 10A. Then I bumped it up to 16(15) A. Worked great. I never went back but I will assume the GPS will remember the current at that site.

[ra-san]

Also note the coiled cord shown is an unsafe practice and no power is present in the picture.

I'll probably feel stupid for asking, but what's unsafe about the coiled cord shown?

[DaveD]

I'll probably feel stupid for asking, but what's unsafe about the coiled cord shown?

A wire carrying current will heat up, and coiling the wire will concentrate the heat, possibly causing materials (like the insulation on the wire) to overheat and melt. Bad things can then happen.