charging on generator

[cracovian]

Phil - I don't understand what you just said... The resistor mod, as described earlier in the thread, was applied and it makes the '12 modified EVSE and '13 unmodified EVSE work great. My Clipper Creek still doesn't work though

I finally ran the generator dry in less than three hours (burned gas much quicker than advertised) and I ended up putting 4.7 kWh that gives me ~17 MPG. I discovered that my older modified EVSE runs 16 amps from the generator and even 17 amps from a regular 120 V outlet but only when charging the '13 LEAF (1.9-2.0 kWh.) Is this safe? It runs regular 1.4 kWh when charging my '12 LEAF. How and why would this happen? I prefer faster charging but it doesn't seem right.

 

[Ingineer]

I can't comment on the Clipper Creek unit, I have no idea how they do their ground verification.

Our older Gen 1 upgraded units will indeed run 16A on 2013 and up LEAFs. This is because of a change Nissan did. Our newer software addresses this with full programmability on both 120v and 240v modes. It shouldn't hurt anything, but be warned you will be pulling over 15A and this could trip breakers on 15A 120v circuits. We recommend you send your unit in to have the newer software applied. (Contact us for more information)

-Phil

 

[dgpcolorado]

Phil, On the subject of gen 1 units, is it true that they won't work on Teslas? If so, can this be changed? I was hoping to use one of my two upgraded EVSEs on a future Tesla, should I ever be able to afford the Model 3. Or, perhaps, the Tesla can just be plugged into the wall with the included cord, so it would be moot (not sure).

 

[Ingineer]

The Gen1 units lack the -12v pilot spec that Tesla is looking for, and since this is a hardware limitation, it cannot be fixed with any kind of upgrade. Most EV's don't care about this, but Tesla chose to. Maybe they will change this in the future.

-Phil

 

[cracovian]

Thank you so much for your response, Phil! It all makes sense now. With the upgraded software, are you still able to select 16 amps if needed? I like it, especially if the outlet or the generator can handle it...

Going back to the generator, I just noticed it only takes .95 gallons, so the MPG would be closer to 20 based on my 4.1 mile/kWh efficiency. The specs call for four hours of running time at rated capacity (2000 watts) but I got much less than three hours at 1,900 watts, so not very happy about that...

 

[dsinned]

Ok, I'm a little confused now. I'm pondering the idea of charging from a 240v capable generator with an L14-30 (without a ground rod), and I'm not sure if resistors would be needed from just the neutral to ground, just both hots to ground, or all 3. Maybe any option would work, but I'd like to know which is preferred. A few pages back, Phil said this:

If you have a 240v capable generator and you intend on charging @ 240v, then barring a proper bonded ground with ground rod, a 100k resistor from neutral to ground should suffice.

You generator is single phase, so there is only one phase center-tapped to provide 240/120v. Most of these small generators have a switch to select from 120v or 240v/120v. That usually re-arranges the windings to be in parallel rather than series, so if you are having only 120v loads, you get double the current and no need to balance.

Then a few posts later he said this:

If you have an EVSE upgrade (rev3) the ground detect functionality is selectable. Contact us for the codes.

For others, I recommend the same configuration for 240v operation, connect the 2 resistors, one each between each hot to ground, like a "Y". Effectively the same as 120v connections.

So which is it? For this hypothetical scenario let's assume we're not using an EVSEupgraded unit (nor a Leaf, for that matter, but we'll forget about that...)

Have the questions raised in the above post been answered? I have not tried this internal grounding scheme yet on my 3500W (continuously rated) generator while charging a RAV4 EV from my L2 EVSE (JuiceBox). I could not get it to work at 240V at any output amperage while the generator was selected to output from the switch seleted 120/240V L14-30R outlet. However, I did get the generator to charge using the 120V OEM charge cord that came with the RAV4, which I believe is limited to 12A. I also tried my VOLT's 120V OEM charging cord (limited to 12A) and it worked too. Both OEM charging cords were still bone stock.

On the L2 EVSE JB, the generator would initially bog way down and cause the car to fault while attempting to initiate a charge. It would only recover when I unplugged and started over, only to bog again with another RAV4 EV system charging error. This happened repeatedly even while limiting charge current from the JB to <10A (2.4kW). Would this behavior go away with the dual resistor grounding mod???

 

[QueenBee]

Ok, I'm a little confused now. I'm pondering the idea of charging from a 240v capable generator with an L14-30 (without a ground rod), and I'm not sure if resistors would be needed from just the neutral to ground, just both hots to ground, or all 3. Maybe any option would work, but I'd like to know which is preferred. A few pages back, Phil said this:

If you have a 240v capable generator and you intend on charging @ 240v, then barring a proper bonded ground with ground rod, a 100k resistor from neutral to ground should suffice.

You generator is single phase, so there is only one phase center-tapped to provide 240/120v. Most of these small generators have a switch to select from 120v or 240v/120v. That usually re-arranges the windings to be in parallel rather than series, so if you are having only 120v loads, you get double the current and no need to balance.

Then a few posts later he said this:

If you have an EVSE upgrade (rev3) the ground detect functionality is selectable. Contact us for the codes.

For others, I recommend the same configuration for 240v operation, connect the 2 resistors, one each between each hot to ground, like a "Y". Effectively the same as 120v connections.

So which is it? For this hypothetical scenario let's assume we're not using an EVSEupgraded unit (nor a Leaf, for that matter, but we'll forget about that...)

Have the questions raised in the above post been answered? I have not tried this internal grounding scheme yet on my 3500W (continuously rated) generator while charging a RAV4 EV from my L2 EVSE (JuiceBox). I could not get it to work at 240V at any output amperage while the generator was selected to output from the switch seleted 120/240V L14-30R outlet. However, I did get the generator to charge using the 120V OEM charge cord that came with the RAV4, which I believe is limited to 12A. I also tried my VOLT's 120V OEM charging cord (limited to 12A) and it worked too. Both OEM charging cords were still bone stock.

On the L2 EVSE JB, the generator would initially bog way down and cause the car to fault while attempting to initiate a charge. It would only recover when I unplugged and started over, only to bog again with another RAV4 EV system charging error. This happened repeatedly even while limiting charge current from the JB to <10A (2.4kW). Would this behavior go away with the dual resistor grounding mod???

It sounds like your generator may already have bonded the neutral and ground and that's why you've been able to successfully charge.

The bogging down is not related to this issue. If you needed the resistors you'd know because the EVSEs would not work and would indicate a missing ground.

I suspect the issue is with the generator itself. Try connecting some other loads like resistive heaters to see how it handles them and slowly increase the number to see where it starts to bog down.

 

[dsinned]

It only "bogs" outputting at 240V. I can put various loads on it up to about 15A at 120Vac (1800w). This is the max load on one of the generator's AC outlets before the CB trips. It is also the max load allowed on the generator's 240V outlet.

Bogging also occurs, (although not initially, after ~2 minutes, but is self-recoverable) on the 120V OEM L1 charger. When this happens I am applying the load via the OEM charge cord's highest (12A) current limiter setting. However, when Earth grounded the generator, this bogging behavior seems to go away.

The strange thing is the generator will NOT output initially without bogging so badly it creates a fault in the car's charging system, which can't be recovered without unplugging and restarting the charge over again. But, it keeps on bogging and faulting each time. I don't see any errors coming from the JB. The bogging/faulting only happens when the generator is selected to operate in the preselected "240V" switch position (i.e. with windings connected in series).

I thought the J1772 only allows the load on the EVSE to ramp up slowly, but that is not what appear to be happening on the generator when it is outputting through the JuiceBox, which operates flawless when powered up from a 240V wall outlet.

I'm using a "DuroStar" (Chinese made) generator "rated" for 3500W with a peak (surge) capability of 4400W, but it sure doesn't perform like it; at least not at 240V! :roll:

 

[BrockWI]

When I have tried this in the past it seems the on-board charger sort of "hits" in, it doesn't ramp up slowly, I wish it would. I imagine the genset sees the hit, starts adding fuel, but by the time it can ramp up the voltage falls out of spec for the EVSE / charger and shuts down the process. I have tricked the genset in to loading by adding restive heaters and quickly unplugging them when the next load hits. Ultimately though this means the genset is undersized for the load, even though once up and running it could handle the load. Larger more expensive gensets will have larger mass "flywheels" so to speak and thus motor starting or loads like this can hit and the genset won't drop in RPM as quickly.

FYI, I also charged our leaf for about 2 hours on our Honda 2000i and I calculated it to be about 22 mpg charging that way.

 

[Slow1]

All this discussion makes me want to fire up my generator and see what happens

I've never used it as once I fire it up I expect I'm at higher risk of issues due to old fuel... It is supposed to be capable of 6500w with peak 8000w - bought to provide emergency power for most of my house. It is one of these: Westinghouse Model # WH6500E.

So, assuming I ground it like it suggests in the manual (I plan to have a line run to my house grounding pin), anyone hazard a good guess whether it would work to charge the car? I'm using an ESVEUpgrade cable right now on my 240v plug in garage.

I'm assuming I'd have to plug the EVSE directly into the generator.

This is all "just in case" thinking - somehow I doubt I'll need it, but if I did, I may not be able to seek helpful advice here during whatever weird event creates the necessity...

 

[fooljoe]

Interesting. Dsinned, could you not get 240v charging to work even at the lowest possible amp setting on your juicebox (6 amps?) If you can at least get it to work at 6 amps, perhaps you could then gradually increase the amperage while charging. The car's charger will adjust to a changing pilot on the fly, so you could perform a gradual ramp up yourself.

 

[dsinned]

Interesting. Dsinned, could you not get 240v charging to work even at the lowest possible amp setting on your juicebox (6 amps?) If you can at least get it to work at 6 amps, perhaps you could then gradually increase the amperage while charging. The car's charger will adjust to a changing pilot on the fly, so you could perform a gradual ramp up yourself.

fooljoe, yes, I tried that, but still no go. It seems while attempting to charge my RAV4 at 240V from the generator, via my JB, the initial load applied to the generator simply starts way too high even with the JB adjusted to <10A. The drop in generator's output voltage was excessive at the point of initial load application. I don't know why this was happening. Surely, expected would be better than that. If, however, somehow the applied load initially presented by the car's onboard charger was excessive, that would explain it. This generator initial load sensitivity issue was really only evident when attempting to output at 240V, not at 120V.

Before I attempted this "experiment" I received lots of feedback on this and the RAV EV forums that since the generator does not put out a pure sinewave, there will be problems like this. But then why did it work at 120V from the same generator? Generator charging a RAV EV at 120V wasn't exactly problem free either, but at least it worked fairly well (=<12A). Also, I was able to charge my VOLT from the same generator as well. However, I don't believe I tried to charge the VOLT at 240V. I should have tried that to see what would happen, with the JB's current limiter set to =<15A to prevent overloading the generator and/or tripping the CB. I suspect it might have been successful, but only with the JB's current limiter would have to be set much lower, probably to =<10A. This would result in a load of about 2200W on the generator because the output voltage would drop to ~220V. This appears to be the generator's "sweet spot".

Another observation, this generator has very poor frequency regulation (governor speed control) under varying load. For this reason alone, I would not recommend it. I hooked up a tach to monitor the generator's rpm. 3600 rpm corresponds to 60Hz. At no load, the generator "idles" as high at 4200rpm (70Hz!!!), but under heavy load, the rpm drops to about -10 to 12% below a nominal 60Hz. Such wide swings in frequency may wreak havoc with an AC/DC SPMS such as used in the JB, not to mention an EV's onboard charger.

 

[dsinned]

When I have tried this in the past it seems the on-board charger sort of "hits" in, it doesn't ramp up slowly, I wish it would. I imagine the genset sees the hit, starts adding fuel, but by the time it can ramp up the voltage falls out of spec for the EVSE / charger and shuts down the process. I have tricked the genset in to loading by adding restive heaters and quickly unplugging them when the next load hits. Ultimately though this means the genset is undersized for the load, even though once up and running it could handle the load. Larger more expensive gensets will have larger mass "flywheels" so to speak and thus motor starting or loads like this can hit and the genset won't drop in RPM as quickly.

This would certainly explain what I was observing as well. I also tried switching off a resistive heater (constant) load, but couldn't quite get it to work. The generator's output fluctuation was just too abrupt and severe to "catch it" at just the right instant. The response time of the generator's speed control governor when a heavy load "hits", is just too slow to maintain sufficient AC voltage and frequency regulation; especially evident when adding in a 240V load.

 

[frbill]

I have a brand new (purchased in Sept. 2014) EVSE Upgrade and I would like to get a generator to charge my Focus Electric in case of power outages. I have read the entire thread and I understand that I would need to do some modification by adapter plug or other method to overcome the ground fault problem. I found a 10kW generator on amazon for a little over $1k and would like to use it.

. Here is the panel for the Generator. So I have 2 questions
1. Will doing the 120V 5-15P plug work if I use the 240V 14-50 RV connection?
2. If that will not work what will?

I really would like to get this before winter sets in. I am a Catholic Priest and need to be mobile in any weather. Prudence dictates having some sort of backup should power go out for a significant period of time.

Eventually I will get a whole house generator, after I save up for it. The above mentioned generator should fill in the gap until I save enough to put in a whole house system. Many thanks in advance for your help. I need as simple an explanation as possible as all things electric are a bit of mystery to me.

Peace,

Fr. Bill Kessler

 

[fooljoe]

Unfortunately, Bill, there's no easy answer. Maybe it'll work, maybe it won't. Maybe it'll be somewhere in between (like it could work on 120V but not 240V.) The ground detection stuff you mentioned is easy - the problem is that different generators produce different "quality" power, and different EV chargers (i.e. the thing in the car, not so much the EVSE) have varying levels of sensitivity to the quality of power.

The best advice I can give to anybody considering charging off a generator is TRY BEFORE YOU BUY (or at least have a very good return policy.)

 

[dsinned]

I have a brand new (purchased in Sept. 2014) EVSE Upgrade and I would like to get a generator to charge my Focus Electric in case of power outages. I have read the entire thread and I understand that I would need to do some modification by adapter plug or other method to overcome the ground fault problem. I found a 10kW generator on amazon for a little over $1k and would like to use it.

. Here is the panel for the Generator. So I have 2 questions
1. Will doing the 120V 5-15P plug work if I use the 240V 14-50 RV connection?
2. If that will not work what will?

Certainly having a "10kW" generator should be powerful enough for charging any EV at 115V and quite possibly adequate for charging certain EVs (e.g. the LEAF) at 240V as well. There is still no guarantee. My Chinese built generator sold under the name, "DuroStar", is "rated" for 3.5kW (sustained), which was barely adequate for 115V at 8A charging. Even though my generator has a surge rating of 4.4kW, it just wasn't enough for 240V charging even when I dialed down the EVSE's current limiter to <12A. YMMV, but please let us know how your 10kW generator performs if you are going to plug in a L2 EVSE to its 14-50R (240V, 50A) outlet. Imho, because of its fairly high output rating, there is a 50/50 chance it may work fine!

Before you buy any generator for $1000 from Amazon, which has some pretty good deals (as does Ebay, many with "free" shipping), be advised that a generator as big a s 10kW, will be quite HEAVY and NOISY. I purchased a 4400 Watt generator (from Amazon, with free shipping), that weighed a little over 100lbs with a noise rating of 69dBa. Because at that particular power rating, it was right at the upper threshold of acceptable weight and noise to use on the road with my EV in case of a charging emergency. Any higher power output and I would not have been able to manage it by myself as far as lifting it in and out of the car, and it would be too noisy to operate outdoors in the vicinity of people. Also, I drew the line with a generator that MUST be able to charge at 240V, via a selectable 120V or 120/240V switch (as shown in the photo your provided) but unfortunately, I discovered that these objectives were mutually exclusive.

 

[GlennD]

I have 2 generators. A Champion Inverter 120V 2000W unit and a 3400W 240V Harbor freight unit.

Using Ingineers ground mod the Champion generator works fine with the included Panasonic L1 Charger.

The other was a waste of money. With the generator running and the EVSE set to 12A, as soon as I plug it in the generator trys to apply throttle. The generator bogs down, the EVSE errors out, rinse and repeat.

The inverter holds up the power. The non-inverter unit does not. It was a waste of money but it powers my refrigerator fine.

 

[dsinned]

I've seen the same behavior on my 3500W (Chinese made) generator. These generator designs just do not have a good enough voltage and/or speed (frequency) control regulator. It essentially "browns out" temporarily whenever a heavy load is applied.

 

[cracovian]

So all in all, my little Honda eu2000i charging at 1.9 kWh using the second gen modified EVSE doesn't seem so bad or slow anymore. It's rated at 2K, surge at 2.2K but holding steady (and loud!) at 1.9K for hours until gas runs out.

 

[Graycenphil]

If you think tat EU2000 was loud, try one of the non-inverters and you'll hear loud.

In general, if you can afford it, a Honda or Yamaha inverter generator is a much better choice in portable generators.