J1772 Gem charging level 2

Working on some 72v EV chargers that became available on the surplus market.
At this point capabilities are unknown.
96-260vac input

As I have never worked with J1772 charging, it may take a week or so to do testing. Charger does not activate when connected to 240vac. A level 2 charger is on order, and with luck, chargers will just work when getting proper handshake signal.
About 20pcs will be available after I determine their value.
All new in boxes from factory closing. Ev being built used 24s lifepo4 battery pack.

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That’s sounds like a great idea.

Productive day. Vehicle plug came in allowing me to make a test harness for J1772 station.

Worked great first try, which is strange. Never happened before. :stuck_out_tongue_winking_eye:

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@grantwest Almost ready for a real world test.
Charger needs a 12v dc supply, which I can build into charger to make it simple.
The enable wire is a plus voltage that should connect direct to Chargery bms24t. You can skip that part for now.
Will 86v charge enough for a test if you run battery down? I guess you would need to get down near 3.5v. Can you do that?

If no, I need to find someone with level2 charger and 21 or 22s battery.
24s lifepo4 is ok too.

I guess it would quick charge lead if someone were to babysit voltage.

I am willing to help as well, I have a Tesla 80amp charger in my garage, would not take much to wire in a J1772 as well. This is a cool project.
Will 86V be the MAX charger from these? Seems like we should be able to use the BMS to set the MAX as before, When you charge at a public J1772 or Tesla charger the car dictates when to stop charging. It just a constant 20A, 30A, 48A charge until the car stops it.

I have 2 Gems right now
Gem #1 is a 82 volt 20 cell
Gem #2 is a 98 volt 24 cell

So either one of the cars can be used to test.
I have a level 2 charge station at work that I could take and wire up here at the lake house.
I would have to wire in a 220 outlet but it would be worth it

Looks like Grant will win this one. Is a bms in the 20s car. I will need to set it up for bms, or you will have to stop charging manually.
This could happen very soon if I don’t get sidetracked or fall asleep. :slight_smile:

Even the company rep in Chandler said the voltage can’t be changed without a trip to China.
That won’t stop me from trying.
Also was informed that this was a limited run. J1772 chargers are not available for less than 100pcs moq. I only have about 20.

So, Grant:
What you can test is a charger-plug and play? 2 connections. Your level two station and a connection to bms?

The last detail is finding a 12v supply required by chargers. Is it a pita to get a couple ma of 12v power from the Gem? Always on to allow charger to function.

Or I can build in a 12v supply somehow.

A 12v power supply would be nice. Or I’ll have to grab a 12v source from the dash, and then run 12v wire to the back. No big deal. Only bummer all this work is for a car I’m selling. I would really like one (J1172) 220v Charger for my High Voltage car!

What’s your guess on this chargers output at 220v I hope it would be in the 30 amp range.

But 100% for sure I’m down to do the work and test.

Here is the last thing I needed to test. bms-24t interface. Works perfectly.
I can send it right away, but I needed it tested soon. I’m out of business until I buy another J1772 plug. At $69 for the bare plug, I don’t want too many on the shelf.
See if you follow this. Not as complex as it looks.
There are two sockets on charger. A 3p and a 5p. The 3p is for 12v in. The 5p is for BMS enable.
Should be plug and play. But you know how testing goes…

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Send me a dollar as payment for goods.
If we come to some agreement on purchase. You can just send the J1772 plug back and build your own.
Or I can buy another if you pay me large sums of money for wiring this one. I’m sure you can copy it.
The charger comes with the Andersons shown.

I’ve measured up to 30a. Usually in the 20s. It has to do with battery volts and J1772 communication.
Field testing is your job…

Now that I’ve done the research. Seems I could make a kit that a dq would plug into. May be simpler than changing the voltage on my elite chargers.
It can also be made with two iec plugs that will run two dq chargers from a single level 2 charger.
One short cord for the stock charger and a long one to ???
Looks like I’ll need another tester after the parts come in.

Anybody home?

You should get charger tomorrow. Not much I can do until I get some real world suggestions.
Can’t even put one in my 22s el, as only have the one inlet plug. If you decide it works for you, I’ll get another, or a longer one for you.

These question will make sense when you have hands on.

  1. Will it work in a practical way
  2. Mount on-board
  3. Inlet under seat or routed near factory inlet, front
  4. Sell charger only, or charger and inlet
  5. Is it a simple matter to supply charger with 12vdc
    Or should I build it into charger (dc-dc)
  6. Will you connect it to bms-24 (plug supplied)
    Or should charger come “bypassed”

Now that I think of it. Charger has a bypass switch. You can test both ways.