My portable 70A charging system for road trippin'

I've got a good friend who's been a motion picture electrician (gaffer) for 30 years or more, and I enlisted his help to modify one of my 70A HPC so it can be hauled around in my trunk on a planned road trip. The idea is to carry every major brand of breaker for either the 40A system or the 70A so I can unscrew the cover on a breaker panel in any American home or business and pop in my own connection to run up to 50' out to my Tesla where the portable HPC or 40A connector will charge it up at a high rate. He's such a pro, he did an absolutely smashing job and prepared it exactly as I requested. Everything is super heavy-duty and way over-engineered. Here are some pictures. First, here's the finished modified unit, where the hook for the connector has been removed along with the cable holder, the output cable has been moved to the side, the original hole plugged (with a waterproof plug), and three camlock connectors have been put into the recessed region where the the connector hook used to be.



Close-up of the camlocks, which mate with an extended cable my buddy is making for me right now, which will be 50' long:



Next, the inside view, where I wish I could show you close-up details of how the new lugs and connectors were so professionally treated, covered with double heat-shrink, and locked in place with stainless lock washers and aircraft nuts.



Here it is inside the trunk, where there's plenty of clearance above. Included is a camera bag containing some other items that are part of the package...



Inside the bag, so far I have these breakers (three of the most common types found in US homes and businesses):



In addition, here's more stuff I've had prepared that stashes in another of the bag's compartments... an in-line breaker with camlocks (in case I can't put a breaker in a box and have to tie-in using clips) and an outlet for use with the 40A charger, which can be carried as an alternative to the 70A one:



Here's how much room is left in the trunk:

Here's how it works.

70A charging with a breaker in the panel: When I arrive at a charging house or business where someone has offered to let me use their breaker panel, I open their panel (four screws) and inspect the type of breakers they use. Then I attach the bare-end short cables which terminate in female camlocks to the proper style of breaker, pop it into their panel (leaving it turned off), and attach the camlocks to my banded cable (not yet shown... I'll post pics later when it's completed). The banded cable carries the current out to the HPC where the cable's female camlocks connect to the panel-mount males. I then turn on the breaker at the panel and press the test buttons in the HPC to verify it's working. I connect the car to the HPC and voila, I'm charging quickly and can go have dinner.

70A charging with no room for a breaker in the panel: I begin by using tie-in clips made from small vice-grip pliers (not shown yet, still being crafted) or trico clamps (shown here: Kaye Lites Inc. ) and use the short cables leading from the clamps to connect to the in-line breaker shown above in the 6th picture, leaving the breaker off. I connect the banded 50' cable to the in-line breaker, carry it out to the HPC near the car, connect it up, and continue with the first example's steps to charge the car.

40A charging with a breaker in the panel: Identical to the first few steps in the first example, but instead of connecting the 50' banded cable to the HPC, I connect it to the range outlet shown in the 6th picture, and plug in the 40A charging cable and connect up the car.

40A charging with no room for a breaker in the panel: Identical to the first few steps of the second example, but ending with the last steps of the third example.

The 40A system is pretty darned small. I'm able to put the camera bag with the breakers, in-line breaker and utility box into another bag that holds the 40A charging cord coiled around it, and it all squeezes into one corner of the trunk. I've tried it... it's actually amazingly small. There's still enough room in the trunk for a large carry-on bag, a computer/electronics bag, and one other small bag or other item in the opposite corner. In the deepest part of the passenger well there's likely enough room for another bag of the proper dimensions too.


How much does it weigh? I'll know more soon about the 70A system, but at the moment my estimate leaves 35 lbs for luggage. There's so little room left for luggage I doubt it will weigh more than that anyway.

I've found a lightweight duffel-style carry-on that's 7.5 lbs which will fit when I'm carrying the 40A charge cord and kit, but that's much lighter... that whole kit only weighs around 45 lbs, leaving lots more for luggage. Once again, I'll know more in a little while when the 50' banded is finished.

Here's a close-up picture of the washers and the lugs connected to the panel-mount camlocks. The camlocks have two brass washers (one on each side of the lugs), then stainless lock washers (not visible), then aircraft anti-vibration nuts holding them in place (not visible). There's no way they can come loose. The camlocks are held in place with three bolts each, also going to lockwasher-backed anti-vibration aircraft nuts. It's absolutely bomb-proof.



Here's a close-up of the strain-relief on the main cable which has been improved with metal parts on the inside of the box:

TEG said:

Wow! Be careful though!
Are you an electrician yourself? You best know exactly what you are doing when opening up breaker panels like that.

Click to expand...

Yes, I'm an electrical engineer and I've had this type of system around for years for working on indy film and music videos. I've tied in to 240 using the clips and have done a lot of home wiring... you put on a pair of leather gloves and there's no problem. The only danger is accidentally shorting and burning something, but I doubt I'll have to use clips at all. Plugging in breakers is a breeze. The camlocks are all code... they have very heavy insulation on them and you'd have to try really hard to get a shock.

Which is why I have two different types of clips to tie in as well. One is a welding type (link above) and the other is a vice-grip pliers type.

It's temporary. What difference does it make if the homeowner or business owner agrees to the temporary installation? The entire movie industry relies on this type of hookup... it's the only kind that exists outside of dragging generators around. I don't see the difference.

Obviously the panel has to be examined to make sure I'm not going to overload the wiring. For example, any electric dryers, ranges, water heaters or HVAC systems have to be shut down if possible during charging.

Where's your sense of adventure? This is a road trip! 8^D

Absolutely. It's certainly not for the meek. Many things could go wrong, but honestly, I can't figure out any other way to pull off long-distance travel through states with no EV charge points.

Hmm. I have a high-leg delta in my shop, which I understand, but I'll have to ask my electrician buddy about standard delta panels. I guess with enough snooping around with a voltmeter I could figure out which leg not to use! 8^D

That one's high-leg delta. Regular delta apparently has one leg that's neutral instead of that tap being neutral.