Accessing J1772 (Level 2) EV Chargers to charge Van/RV lithium system

[berksrunner]

I've been thinking about this for a while, with a couple of false starts over the past year and a half, but I think I finally have the necessary pieces to make this a reality for my van system (DIY lifepo4, 24V configured as 3 parallel 8S batteries, total of 6.2kwh, Overkill BMS for each 8S battery).

Here's the equipment which I have ordered and am eagerly waiting to have delivered:

1. J1772 to NEMA 5-15 receptacle

J1772 to NEMA 5-15/5-20 EV Charger Adapter for E-Bike/Scooter/One wheel, etc. – EVSE Adapters

www.evseadapters.com

2. Mean Well 1500W 240VAC to 27V Switching PSU with enclosure

Amazon.com: Mean Well RSP-1500-27 Enclosed Switching AC-to-DC Power Supply, Single Output, 27V, 0-56A, 1512W, 3.3" H x 5.0" W x 10.9" L : Electronics

Buy Mean Well RSP-1500-27 Enclosed Switching AC-to-DC Power Supply, Single Output, 27V, 0-56A, 1512W, 3.3" H x 5.0" W x 10.9" L: Uninterruptible Power Supply (UPS) - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Yes, it does seem odd to use a NEMA 5-15 for 240VAC (and most certainly non-compliant), but I believe, for a short run, the important thing will be whether my wire gauge is adequate, which it most certainly will be since 1500W (or less) @240V is obviously pretty low current. And, of course, I can't make any mistakes -- I've got to make sure the Mean Well unit is at the other end of that wire, or else something is going to fry.

I plan to use 6AWG between the Mean Well and my bus bars, and I'll likely set the voltage at around 28.8.

I'm excited about this, because I've got an electric water heater which is fine in summer, but as winter approaches, the solar is a bit harder to come by, and I hate paying for a campground just to charge my batteries. I am constantly driving by extremely sparsely-used EV charging stations here in Colorado, and it just seems like an enormous waste....plus I'm happy to pay for the 30-45 mins of charging that I'll need to get me over the top on a day when I want to take a nice hot shower in my van.

Any thoughts?

 

[snoobler]

The PSU is wide range input single phase. It will deliver its rated power at 120VAC. If you hook it to 240VAC, do NOT ground the PSU. You have to run with a floating ground. Since a split phase 240V system has a ground bonded neutral, you will short out the supply if you ground it. In 120VAC it's fine since you're using the Neutral and one hot, but now you need two different power cords if you go to standard 120VAC outlet... or you always float the ground.

IMHO, the ability to charge off any standard 120VAC receptacle (the level 1 charger) is more valuable than the novelty of utilizing a level two charger.

Alternatively, can you just pick up one leg of the level 2 charger?

 

[berksrunner]

I'd love to keep it simple with level 1, but have you done a search for level 1 public chargers lately? They are few and far in between.

I'm going by the claims of supplier of the J1772 adapter cable that I am somehow getting 220VAC out of the hot-neutral-ground of their NEMA 15, and I've looked at the wiring diagram for the PSU -- it does seem to require a conventional hot-neutral-ground. I am not planning to ground the PSU -- I don't think Mean Well provides a way to ground it.

Does any of this make any sense? Again, I'm just going by the claims of EVSEAdapters.com -- and they claim to have tested it with a Vespa Elettrica. There's also a reviewer who claims it works with his electric motorbike.

 

[Ampster]

Does any of this make any sense?

Yes it makes sense. Use Plugshare to find Level two chargers. There are even free ones some places.

 

[berksrunner]

Again, it really comes down to what this adapter is able to do -- it seems to provide a single phase, Euro style 220 via a nema 15.

 

[berksrunner]

Or perhaps they really are just capturing a single leg of 120 which they are passing to their receptacle -- but then why all of the warnings about 220V in their product description?

 

[berksrunner]

The more I think about this, the more certain I'm becoming that the J1772 adapter I've ordered is somehow only providing one leg of the 220 from the charger. Perhaps the following verbage from their site is some odd attempt at CYA -- or maybe even it's an attempt to make competitors believe that they have accomplished something a bit more advanced than simply splitting off one of the legs:

CAUTION! Make sure your EV charger or appliance is configured to operate on 220V before connecting to the charging station! Most charging stations operate at about 220V, so this is very important. Refer to the label on your device’s power supply – if it indicates it can accept 220V or above, then you can definitely safely use it with this adapter; however if not, then please DO NOT USE – misuse may damage your device.

 

[berksrunner]

Now, I'm thinking that I really don't need that expensive switching PSU, since I'll bet I'm only getting 120VAC out of that NEMA 5-15 receptacle -- would love to hear some opinions.

 

[berksrunner]

I really don't know enough about AC power, so I know I'm showing my ignorance. However, I've done some more searching and found this interesting tidbit at http://modularevpower.com/J1772_adapters.htm

Scooters and NEV’s

For Scooters (Vectrix) and NEV’s that can charge on 120 or 240 volts, J1772 can be used. If the charger is only suitable for 120 volt operation J1772 is a problem since it only provides 208 or 240 volts.

We have J1772 to NEMA 6-15 receptacles (240 Volts, 15 amp). NEMA 6-15 receptacles are the correct one to use for this application.

If we made an adapter with a NEMA 5-20, standard household receptacle, intended for 120 volt loads, it is trouble waiting to happen. Sooner or later a 120 volt item would get plugged in and the results would not be good.

What we would recommend would be to replace the present NEMA 5-20, standard household plug on the vehicles cable with a NEMA 6-15 plug (240 Volts, 15 amp) that you can get at a hardware store so it is expecting to plug into 240 volts. That can plug in to one of our adapters or a 240 volt receptacle.

Then make an adapter with your old plug (120 volt household 5-15) and a cable mounted NEMA 6-20 receptacle (female) for charging on 120 household power. The 6-20 accepts both 6-15 and 6-20 for more versatility. Use a foot or two of SO 12/3 cable in your adapter cable. If you presently have a molded plug cut it off leaving 6-12 inches of cable to make the adapter. The green wire goes to the green ground screws. The Black wire goes to the gold screws and White wire goes to the silver screws on each end.

What this tells me is that it is somehow possible to feed 220 volts into a NEMA 5-15. I don't understand how you do that without having two hots -- perhaps someone can explain that to me.

 

[evad]

The receptacle just provides contacts so what ever voltage you apply to the terminals it conducts to the sockets. The voltage and current rating is just a convention so that you can provide a power supply which matches the device you are using.

 

[snoobler]

Yes, you should have two hots. After digging a little deeper, and scratching my head more, if all you're getting out of the 15A plug is 240V between the blade sockets and 0V from the ground socket to both blades, then it should be fine.

 

[berksrunner]

Yes, you should have two hots. After digging a little deeper, and scratching my head more, if all you're getting out of the 15A plug is 240V between the blade sockets and 0V from the ground socket to both blades, then it should be fine.

Fascinating! Thank you!

 

[berksrunner]

BOOM!! It works!!! Thank you everyone!!!

 

[berksrunner]

BMS pics (3x24v lifepo4 in parallel; 8S diy 86ah cells)

 

[schmism]

There seems to be some steps missing here.

It would appear as if you have used a level 1 J1772 inlet to interface with the standard charging station.

However as snoobler pointed out, Level 1 charging is "dumb" (requires no communication). How are you doing the negotiation that is required for level 2 chargeing (at the higher voltage/rate)?

 

[berksrunner]

There seems to be some steps missing here.

It would appear as if you have used a level 1 J1772 inlet to interface with the standard charging station.

However as snoobler pointed out, Level 1 charging is "dumb" (requires no communication). How are you doing the negotiation that is required for level 2 chargeing (at the higher voltage/rate)?

Well, I mean, it works, first and foremost. I've only used ChargePoint thus far (as well as a family member's garage equipped with level 2).

What I'm assuming is that the J1772 to NEMA 5-15 adapter I purchased contains the chipset that communicates with the station, releasing the current. About a year ago, I purchased one of these chipsets and attempted to create my own adapter, but this unit I purchased more recently makes it dead simple.

 

[BiduleOhm]

How are you doing the negotiation that is required for level 2 chargeing (at the higher voltage/rate)?

Level 2 protocol is very simple, you don't need much electronic to implement it

 

[berksrunner]

And by the way, this is NOT level 1. It is level 2 @ 220V nominal. Level 1 is nothing more than a dumb NEMA 5-15. I am using J1772 and actually logging into the ChargePoint network.

 

[Ampster]

And by the way, this is NOT level 1. It is level 2 @ 220V nominal.

If i understand correctly you are using a level 2 receptacle but only using half of the power (one leg at 120 volts) to a power supply.

 

[berksrunner]

If i understand correctly you are using a level 2 receptacle but only using half of the power (one leg at 120 volts) to a power supply.

I believe I have two hots which makes for a true 220 volts, but I'm drawing very low current -- like maybe 7 amps.