Bag of Spare Adapters?

Bag of Spare Adapters?

TM now has several adapters for sale. Is there much benefit to buying some or all of them to have on hand when out on the road?

shop | February 2, 2014

Btw, I highly recommend getting the Tesla NEMA 5-20 adapter. I just finished a 24 hour trip (3 hour drive, stay overnight, drive back the next evening), and it was critical that I could get enough charge in that overnight period. The only plug available was a garage 120V plug, but luckily it was a NEMA 5-20, so with my adapter, I grabbed 50 miles of charge overnight versus 34 miles if I had only the default NEMA 5-15 adapter that came with the Tesla. Yes, that extra 16 miles did mean something - peace of mind and the ability to drive fast on the way back.

Various adapters do come in handy from time to time.

pstaffor | February 27, 2014

So far I haven't found the NEMA 5-30 mentioned. I have a house vacuum plugged into a high-amp 110V outlet. I know the adapter for the Tesla immediately drops the current pull if it senses 110V rather than 240V, but it would be nice to get ~24 amps from a 110V plug that already exists in my garage. It's plenty for my driving range. A NEMA 5-15 is not. I hate to invest in a 240V install when I don't really need it. Anyone know if the Tesla charger is current-restricted BECAUSE it's drawing from a 110V source or BECAUSE the 110V source won't supply more current? The designer for our house had installed nearly 100kW worth of solar panels, and put in industrial-grade wiring throughout, so there are a number of 110V high-current outlets that are NEMA 5-20 and 5-30. Tesla made it clear they won't provide a 5-30 adapter, but I think I could make one if the car can pull 24 amps from 110V. This seems like the correct forum to ask this.


LMB | February 28, 2014

(LMB spouse)

@Shop - Might want to be a bit careful with 5-20. Non-professionals who install outlets aren't always careful about wire size, breaker rating, or shared loads. If you know everything is good or you can check it, no problem. Otherwise...

shop | February 28, 2014

@pstaffor - NEMA 5-30 are not very common, so I'm not surprised that Tesla won't be making such an adapter. You have several options.

1. Buy the Tesla 5-20 adapter. I believe (don't know for 100% sure though) that a 5-20 plug can fit into a 5-30 receptacle. With the Tesla 5-20 adapter, you'll be able to charge at 16A, 120V. This will give you about 5 miles an hour, or 60 miles for a 12 hour period.

2. Make your own NEMA 5-30 to NEMA 14-50 adapter, and then use Tesla's NEMA 14-50 adapter. You will then be able to charge at 20A (since Tesla's software limits you to 20A charging at 120V). This will give you about 75 miles of range per 12 hour period.

3. Splurge the $500 or so to have an electrician install a 240V receptacle.

As to why Tesla limits 120V charging to 20A, beats me. My wild ass guess is that they didn't realize there were many 30A 120V sources, and they decided to be ultra cautious and limit charging so as to not pop breakers in case people started making their own home made adapters and using them improperly.

Note that you should not use the same circuit as your house vacuum should you decide to use one of your 30A 120V circuits. The Tesla load and the vacuum load together would trip the breaker (hopefully).

shop | February 28, 2014

@LMB - don't worry, the 5-20s I've seen were in relatively new condo garages - there is little doubt they didn't build them to code. The 5-20s weren't add ons...

shop | February 28, 2014

@pstaffor - 100 kW solar array? Really? That's like 260 panels - That's like 10,000 square feet of panels - or about 1/4 of an acre.

Chuck Lusin | February 28, 2014


If you have 100kW of solar, you should just get a old 90kW supercharger for your garage :)

public | June 18, 2014

@shop, your adapters PDF at is awesome. Thank you for sharing your knowledge!

I made a NEMA 6-50 to 14-50 adapter using the parts you specified. I'd love for the group here to take a quick look to make sure that nothing terrible will happen if I plug this in! Thank you. I am a new Tesla owner, and am super excited to drive it and to participate in this community.

Pictures here:

dortor | June 18, 2014

@public looks good.

shop | June 18, 2014

Yes indeed, looks good.

Ohms.Law | June 29, 2014

@shop - you saved me. I had made my two 30A 240V adapters per your careful instructions and thought I was good to go for a KOA 30A charge at a friends permanent site. Then at the last possible moment I learned from your (updated) instructions that RV 30A hookups are completely different. Just had enought time to order and make my TT-30 adopter before I left yesterday for upstate NY. It's working like a champ and, without your detailed advice, would have been SOL. You're da man! Thank you.

shop | October 22, 2015

Resurrecting this old thread to point out that Tesla has just posted a NEW adapter that people can buy: a NEMA 6-15.

Never heard of it? Don't worry, you aren't alone!

Odd choice for a new adapter, but hopefully this means that a new NEMA 6-50 adapter is in the works, as well as a new NEMA 14-30 adapter, and maybe others too.

shop | October 22, 2015
hammer @OR-US | October 22, 2015

I noticed that today as well. That does make it possible to add a two pole breaker to an existing 120V 15A circuit and double your charge rate. Of course all outlets on the same circuit will be 240v as well but I've seen garages that have dedicated circuits for refrigerators or workbenches that could be re-tasked.

Rocky_H | October 23, 2015

@shop, Yes, that is the most confusing thing, since 6-15 is almost nonexistent out in the wild. Why would they add an adapter for that one. Also, on an odd note: notice anything odd about it? Look at the orientation of the raised plastic part with the "T" logo, versus the metal pins. The raised plastic is the "top" of the adapter, so the UMC cord will hang down below that, but the plug pins are rotated a quarter turn, so whether the 6-15 outlet is installed right side up or upside down, the UMC is going to have to hang sideways with strain on the plug. Design screw up?

@hammer, Thanks for pointing that out. The needed wire thickness is based on current, so you can use a 15A wire for 120V or 240V--cool.

Oddly enough, I had already made an adapter for a 6-15, because I got a Quick220 box that combines two 5-15 plugs, so it outputs in a 6-15 outlet.

dortor | October 23, 2015

ordered - I'm OCD about having adapters…