Charging issues with 30 amp openevse but not 40 amp openevse

[jimbo69ny]

I am having a minor charging issue with my Rav EV taking a charge from a 30 amp Openevse.

I have built many openevse's and I would say I am very familiar with them. I have two at my house that I use currently. A 30 amp unit mounted to the garage wall on a 30 amp breaker and a 50 amp portable unit that I connect to a 14-50 outlet which is on a 50 amp breaker.

The Rav charges just fine on the 50 amp unit. The max amps is set at 46. But with the 30 amp unit it stops charging after a minute. The unit charges my PIP just fine with zero issues.

When it first happened I thought I tripped a breaker but I didn't. The evse said that the ev was connected, it just wasn't charging for some reason. I had the max amps on the unit set to 28 which I know is high for a 30 amp breaker but it never mattered for the pip because it never pulled that much. I thought that might have been the reason the Rav wasn't charging so I dropped the max amps down to 26. That worked for a day but now the issue is back. I dropped it again to 24 but it is still doing the same thing with the Rav. I tested it again with the pip this morning and it charged the pip just fine. It almost left me stranded this morning. Luckily I noticed it in time this morning to connect my 50 amp evse so I had enough charge to get to work.

Sorry for the long post but do you guys have any ideas? Should I lower the max amps further or maybe try a larger breaker?

 

[srl99]

OpenEVSE has connected message? Any indications from the RAV ?

 

[jimbo69ny]

The Rav has the red message that says charging failed. I think it might say something like charger failure.

The openevse doesn't say anything is wrong. It says ev is connected, it's just not charging. If it was charging the openevse has a timer and says ev charging.

It's weird. I should add that no breakers or fuses have popped.

 

[fromport]

I am having a minor charging issue with my Rav EV taking a charge from a 30 amp Openevse.

how new/old is the openevse ?
I have a v1 which I needed to adjust the resistor in order to work with the RAV.
It sometimes worked, and sometimes didn't.
The R1 (smd) resistor was a 1kOhm.
For Tesla/RAV4EV compatibility it was changed to 649 ohm
Instead of replacing the resistor , I paralled a new regular resistor of 1k8 on top of the pcb which should make it 642 ohms.
Works great ever since

 

[jimbo69ny]

Interesting. I wonder if that's my issue. The 30 amp is a v2 and the 50 is a v3 but not the newest one that he just started shipping.

 

[fromport]

Interesting. I wonder if that's my issue. The 30 amp is a v2 and the 50 is a v3 but not the newest one that he just started shipping.

I think V2 already has the right resistor.
measure to make sure ;-)

 

[miimura]

You should really set your EVSEs to follow code and only draw 80% of the breaker. 24A on 30A breaker and 40A on 50A breaker. Like you said, it didn't matter on the PIP because it could not draw that much, but you could easily overload the 30A circuit with the RAV.

 

[fromport]

You should really set your EVSEs to follow code and only draw 80% of the breaker. 24A on 30A breaker and 40A on 50A breaker. Like you said, it didn't matter on the PIP because it could not draw that much, but you could easily overload the 30A circuit with the RAV.

I agree with you, but even when he set it to 24 amps, it didn't work anymore.
So how to debug what is wrong.

What if you set it to a real low value like 10 amps. will it finish charging ?
If that is the case, there could a resistance somewhere (from overloading the circuit with 28 amps?!) which
prevents the charger in the rav from working correctly.
I 've heard/read that tesla chargers are relative picky of the AC source compared to other chargers.

 

[jimbo69ny]

I just dropped down the max amperage to 22, 20 and 10, it wouldnt charge at any of them. It seems like it will start to then stops within 15 seconds. The EVSE still says EV Connected with no error codes and still charges my PIP fine.
I have no idea whats up.

 

[srl99]

Heat issue? Bad connection? Power supply inadequate? Does it really start charging? You hear the relay engage? Any way to tell if AC power gets through to J plug?

 

[fromport]

I made a closeup photo of my V2 openevse:

As you can see is says 621 in writing on the resistor 62[1 zero) = 620 Ohm.

Measure yours (one pin of ohm meter could be held against pilot pin)
Other pin on the right side of the resistor or pin 1 (or 5, it's hard to see) of the chip.

If yours measures 1000 ohm (which is how it is marked on the original schematic of the openevse)
you might have found your problem.

 

[jimbo69ny]

Yes it says charging system failure. But it's saying evse issue not the cars internal charger. Because when I plug in my 40 amp unit it says the same thing.

A cheap and easy fix was to upgrade the breaker to a 40 amp unit. I just installed it and I'm getting the same result no matter what the max amps is set to.

I'll have to open up the evse later today and look closer.

 

[jimbo69ny]

I made a closeup photo of my V2 openevse:

As you can see is says 621 in writing on the resistor 62[1 zero) = 620 Ohm.

Measure yours (one pin of ohm meter could be held against pilot pin)
Other pin on the right side of the resistor or pin 1 (or 5, it's hard to see) of the chip.

If yours measures 1000 ohm (which is how it is marked on the original schematic of the openevse)
you might have found your problem.

I just measured it as you suggested and it is 648 ohms.

 

[fromport]

I just measured it as you suggested and it is 648 ohms.

In that case I don't know how to debug this further.

:-(