charging on generator

[muus]

Any idea why you lost 25% from the trailer?

25% is only an estimate. Driving normally I usually get home with 15% to 30% remaining driving mostly at 105 km/h (65 mph). Pulling the trailer I had to drive around 85-90 km/h (53-55 mph). The trailer is 4x8, single axle, don't know how much it weighs. I'm guessing the biggest hit would be due to the aerodynamic drag.

Most of the time I use a hitch mount cargo carrier which doesn't seem to affect the efficiency much.
http://www.princessauto.com/pal/en/...-Aluminum-Hitch-Mount-Cargo-Carrier/8265126.p

 

[camasleaf]

I was hoping for something us mere mortals can afford. ie using a regular gas/diesel generator to put the regular 3.3kw into the car while driving for that tiny bit of extra go in the winter

Not a problem. What you want is called a "Chevy Volt"!

Not the same thing with a Volt. The Volt caries the ICE engine all the time. I am really interested in a gas/propane range extender on a trailer or cargo carrier. I would only use that a few times a year, and prefer not to rent a car for that. I also want to be able to use the range extender as an emergency generator if needed.

Do we even have tread specifically for "charging while driving"? We could ignore the source of electricity for now. It cold be and ICE generator, turbine, solar trailer, extra batteries .... Could Tesla build a trailer with a 40-60kWh battery that the renter of the trailer could charge at superchargers? I would gladly rent one few times a year.

 

[dsinned]

Tested charging my Leaf with a 3500 W propane generator and my upgraded Panasonic EVSE. First thing I did was to ground the generator to a real ground. (house ground to ground lead on generator frame) Then I set the EVSE to 6A at 120V and plugged the car in, charging started perfectly. I bumped up the amperage and repeated the previous steps a few times until I got up to 12A, worked every time.

My next test was to try to charge on 240v. I set the EVSE to 6A and plugged the car in. The blue LED on the dash started blinking but the generator didn't seem to be loaded (no change in engine sound). After a little while, the blue led stopped blinking indicating that the car wasn't charging. I plugged in a "Kill-a-watt" meter and adjusted the engine speed to get exactly 60Hz (voltage was within tolerance). Still the car wouldn't charge on 240v. Just for fun I plugged in a small (500w) electric heater to the generator then plugged in the Leaf. Now the car started charging. - Weird -

I repeated the above experiment several times and unless the heater was on, the car wouldn't start charging. (I can turn the heater off once charging has begun). I was able to bump up the amperage all the way to 12 (quickly turning off the heater once the car started charging). I didn't go any higher than this since the generator is rated at 2800 W (3500 surge). At 12 Amps that's 2880 W, slightly over its rated output. Besides, the generator seemed to be working pretty hard!

So now I know that if I have a long power outage at my cottage, I will be able to charge up the Leaf to get back home.

Here is the generator I am using (bought used):
http://www.amazon.com/All-Power-America-Propane-Generator/dp/B0035I1UOO

My experience with a similar portable (Chinese made) generator wasn't as successful. My generator is a "DuroStar" with a 3500W "continuous" output rating. I could only get it to work reliably, i.e. to charge my RAV4 EV, when it was used at 120V and 8A, using the OEM charge cord. At 120V, 12A it was problematic, because every few minutes, the generator would act like it was starving for gas, stumble and then eventually self-recover several seconds later. So, that worked too, kind of, but not without frequent "interruptions", thus slowing down the already slow charging rate. However, with the generator switched to the 120/240V mode, every time I plugged in my JuiceBox L2 EVSE to the generator's 240V output receptacle, via an adapter cord, with the EVSE plugged in to the car, the generator would BADLY bog, causing an immediate charge abort. I tried this with the EVSE set to lower current settings, as well as the space heater trick, all to no avail.

Imho, these type of generators do not have sufficiently controlled load (speed) regulation, especially at the higher load, 240V output setting.

 

[AlanSqB]

The heater is basically doing what the resistor hack mentioned earlier in this thread is doing. You can wire up one of those resistor plugs and use it instead of the heater and it should work fine.

 

[fooljoe]

The heater is basically doing what the resistor hack mentioned earlier in this thread is doing. You can wire up one of those resistor plugs and use it instead of the heater and it should work fine.

No, the "resistor hack" is just to spoof your EVSE into passing its check for an earth ground. What the heater is doing is somehow solving an issue where a lower-quality generator (that's properly grounded or already "spoofed") "stutters" when the large demand of L2 charging is suddenly placed on it, and the resultant power quality degrades enough that the car's charger decides charging's not going to work.

 

[AlanSqB]

That doesn't match the description the poster I was responding to described. He described the generator appearing to remain unloaded when the 240 load was added. It sounds more like the grounding issue that the resistor "fixes" and the heater would also do this.

 

[fooljoe]

Were it a grounding issue, the EVSE would report an error and the car would never even try to charge. In this case, the EVSE operated nominally, and the car initiated the charge, but then dropped off.

 

[dsinned]

Fooljoe is correct as relates to my generator experience. I don't believe there was any "grounding" issue, only that the generator's output regulation was so poor, at the instant the "L2" EVSE connects to the car's OBC, that it badly bogs down and momentarily fails to regulate output voltage and frequency. These two parameters dip down so low that the car sees it as a impending brownout condition causing charging to immediately abort. Unfortunately, charging does not attempt to resume after this happens should the generator try to recover. Instead, you must unplug the EVSE from the car and essentially "reset" the car's charging system. This doesn't help, because the same thing will just happen again and your car never gets charged.

The only possible solution is to use a much more powerful generator, capable of holding up during larger load surges, or one that has "precision" output regulation or both. The generator I tried only had a 3500 watt rating (4400W surge) apparently not enough to compensate for an initial 240V load surge presented by the OBC in the car (RAV4 EV).

I believe the "heater trick", when the timing is just right, (which is more likely to be hit or miss), can be used to counteract the effect of a surge and keep the generator's output closer to nominal conditions, thus preventing the would-be brownout event.

 

[muus]

The generator is properly grounded so there is no need for a resister to trick the EVSE. Also the generator doesn't bog down when the car starts charging, the car just doesn't charge. The strange thing is, the blue LED starts blinking then after a little while it just stops. Only with the heater connected does charging actually start.

 

[BrockWI]

As well as the other reasons mentioned, I have also seen gensets unloaded with a to high of an output voltage or or frequency and loading them a bit can put the hz and voltage back in range. Less expensive gensets tend to be about right voltage and freq wise between 1/3 to 1/2 loaded.

 

[muus]

As well as the other reasons mentioned, I have also seen gensets unloaded with a to high of an output voltage or or frequency and loading them a bit can put the hz and voltage back in range. Less expensive gensets tend to be about right voltage and freq wise between 1/3 to 1/2 loaded.

That's what I though at first, which is why I adjusted the frequency to 60 Hz exactly. The voltage was within range (around 245v). With testing I noticed that the frequency would drop a bit when loaded so I adjusted the no load frequency up a little.

 

[dsinned]

This speaks to the advantage of Japanese made "inverter" type generators. Although they are WAY more expensive than most of the Chinese made generators, they tend to have much better output regulation control as well as better load transient response characteristics. It surprises me, that there are so few if any non-Japanese made generator companies adopting more precise output regulation control into their products. For most all digital electronics, which most all modern day kitchen appliances, stereos, TVs and "charging devices" employ, Chinese generators are simply not the best choice due to their potential compatibility issues with "sensitive" electronics. I think the ONLY reason they are even marketable in the U.S. today, is because they are so much less expensive than portable Japanese inverter type generators. In some cases the price difference is a much as a factor of 3 or 4 to 1 for the same output power rating!

 

[nerys]

What about outputting 12v into a small agm battery and they using an inverter with cleaner output on the 12v battery? Expensive? To much losses?

 

[GlennD]

What about outputting 12v into a small agm battery and they using an inverter with cleaner output on the 12v battery? Expensive? To much losses?

I do not think you appreciate how much energy is involved. 12A at 120V is 120A at 12V assuming no other losses.

 

[nerys]

Actually 315 amps. 220v 20 amps to 12v is 315amps.

Generator is pointless at l1. Just find an outlet.

I have no idea what the native output of the genny is. Which is why i asked about the possibility.

The battery would "buffer" the load down as the charger kicked in.

 

[dsinned]

The battery charger "output" on my generator is rated for 12Vdc @ 10A and I believe it is circuit breaker protected accordingly. Thus, at most this output could power an DC to AC inverter rated for about 100 watts.

 

[nerys]

Interesting. I wonder what teh native output of the gennies are?

are there simpy multiple inverters? or is there ONLY the 110v/220v inverter and they added a 12v option to it?

for some reason (no idea why) I had just assumed gennies were 12v machines and the inverter upconverted the 12v to 110v or 220v.

honestly no idea why I thought that but there is it.

is there an affordable 12v 300+ amp option? maybe would be cheaper to buy a higher quality inverter to replace the one on the genny?

or would it be cheaper to simply buy a better genny?

I wonder if EVSE upgrades can program one of these to "ramp up"

will the car tolerate that? ie can the car say start at 1amp and slowly ramp up 2 3 4 5 all the way to its normal 20amps?

if must it negotiate directly to the desired or offered amperage?

I know you can program the upgrades evse's to do other amperages so wondering if they can "ramp it up" from 1amp to 20amp to give the genny time to adjust as the demand increases.

 

[GlennD]

I have a Champion 120V 2000W inverter unit that works fine with the stock Nissan L1 unit at 12A and 120V. I did need ingineer's resistor mod.

My Chinese 3500W 240 generator was a complete waste of money for EVSE use.

Every generator that I have seen just provides limited 12V for charging a battery.

 

[fooljoe]

I suppose you could get a high-power 12V battery charger to take the full AC power off the generator, pass it through a 12V battery (or bank of batteries, as an individual battery would probably not be able to handle all that current), then pass it through a high-power inverter to convert to "clean" AC power. People with off-grid solar probably have much of these systems in place.

But with all those high-power electronics you'd probably be much better off just getting a quality inverter generator in the first place. Plus if the Leaf and other EV chargers balk at the generator's output and won't start the charge, it's possible the 12V charger (which is essentially the same thing) will do the same.

 

[nerys]

Well a car battery can push 1000 cca for quite a few seconds. Long enough for the genny to kick in and stabilize before the battery cries uncle

But if inverters like that are not common or cheap then its a non starter.