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Portable generator

Posted: Fri, 30 Aug 2013, 14:06
by markrmarkr
I guess we would have to look at something like this 5KVA generator then.

at $$639 it's a bit pricey;

Peak rating of 5KVA , and rated output of 3.7KVA, it would probably be ok as long as the PF is close to 1 on the charger. Even with PF = 3.3/3.7 = .89, we would still be within spec for rated output; and

Still do-able (one man lift) weight wise at 55kg (but don't tell the OHS guys). I bet that is dry weight though, so after adding oil and fuel it may not be do-able. Better count on two people to lift it;

Also it's pretty quiet at 59dB at 4m; and

You get a remote start.

Adding up all the cons - the weight, cost, and the fact that even at 15Amps you still have to park the car for hours at a time, it's still not there for me.

I guess I'll have to wait for fastcharge.

Portable generator

Posted: Fri, 30 Aug 2013, 14:14
by offgridQLD
Just the smell of fuel/oil and carbon deposits in the muffler stinking out the passenger area of my Imiev is a turn off to me.

Kurt


Portable generator

Posted: Fri, 30 Aug 2013, 16:38
by acmotor
I'm with you there Mark, that 5kVA gen...
    Dimension: Approx. 600 x 450 x 500mm !!
    Nett Weight: 55 Kg + Fuel Tank Capacity: 14L = ~65kg !!
    4.6KVA AC Output @ 0.8 cos so 3.7kW cont. no headroom.
I'd settle for the 2.2kW charge rate on the smaller gen.

an e-jerry can of 65kg would be smaller, have 4kWh+ and run through 3.3kW charging with no smell.

Portable generator

Posted: Mon, 21 Oct 2013, 00:31
by acmotor
Just a little update...
I tried one of these the other day.
http://www.ebay.com.au/itm/370828404231 ... 1439.l2649

Image

specs:
Max Power Output: 1.5kW/ 2kVA@0.8cos
Rated Output Power: 1.5kVA @0.8cos / 1.2kW
Frequency: 50Hz
Rated A.C Output: 240V
Rated D.C. Output: 12V / 4A

It couldn't charge the iMiEV even at 6A (1500W) with this gen (via current selectable EVSE) . It would start the charge but then the gen would actually shut down the motor after 15 seconds.

So quoted gen power is not always up to the mark !

Portable generator

Posted: Mon, 21 Oct 2013, 02:31
by coulomb
acmotor wrote: specs:
Max Power Output: 1.5kW/ 2kVA@0.8cos
Rated Output Power: 1.5kVA @0.8cos / 1.2kW

It couldn't charge the iMiEV even at 6A (1500W) with this gen (via current selectable EVSE) . It would start the charge but then the gen would actually shut down the motor after 15 seconds.

Well, the specs say 1.2 kW continuous; 6 A @ 240 V is 1.44 kW. Looks like max power is for an impressive 15 seconds only.

The headline 2 kVA (which is probably actually 1.5 / 0.8 = 1.875 kVA, note they only give one significant digit) is only for short duration and at a power factor of 0.8. A mastery of marketing.

Oh wait - on the side, it actually says 2.0 kVA peak, so that should be 1.6 kW at 0.8 power factor, or perhaps they are actually using a power factor of 0.75, which rounds to 0.8 (again, one significant digit).

Portable generator

Posted: Mon, 21 Oct 2013, 02:55
by acmotor
Yep, the message is clear.
One purpose of this thread..... advertised kVA as a number on a generator can be nearly twice the actual useable power in kW !
The sad truth usually lies in the fine print and even then optimism rules !
So... the '4.4kVA generator' will probably be happy (as tested) with a 2.2kW load.

Portable generator

Posted: Tue, 22 Oct 2013, 03:17
by unheardofinstruments
I have to wonder why use an a standard generator when a much lighter and more efficient package could be made using a wind turbine permanent magnet generator and a small motor.

I was also interested in how the dc output voltage is regulated for charging, seems wasteful to me to step up to 240 just to drop back down to 144 (or whatever) DC through the charger to the pack. Why don't regen buck boosters also double as a charger? Seems to me they must have very similar circuitry which raises a varying voltage and regulates it. I would be interested in making a generator that puts out my charging voltage directly in DC instead of 240 AC.

Portable generator

Posted: Tue, 22 Oct 2013, 03:29
by offgridQLD
240AC is less than the DC voltage of most oem EV packs.

Kurt

Portable generator

Posted: Wed, 23 Oct 2013, 07:13
by photomac
You know - RAC have their rescue genny trailer - we should find out what they are using ?

Portable generator

Posted: Sat, 09 Nov 2013, 21:32
by photomac
So - RACWA have an emergency generator for EVs in their trailer - I quickly observed it at the last AEVA presentation in Grogan St, it was small, does this have Nissan/Mitsubishi approval?

Portable generator

Posted: Sat, 09 Nov 2013, 22:17
by Gabz

Portable generator

Posted: Sat, 09 Nov 2013, 23:22
by acmotor
Given that the J1772 (AC) and CHAdeMO (DC) are world standards and Mitsi/Nissan would expect to have allowed for all sorts of power quality, then a generator that met any form of local authority standard for electrical safety would be considered acceptable.

On that point, I have tested J1772 charging via EVSE and the EVSE itself rejects wrongly configured power (A and N not connected) or high harmonic content e.g. modified square wave before even connecting it to the EV.

So 'mitsi/nissan' approval would probably be already built into the EVSE and the EV and anything further would be 'is the generator local power authority approved'. I can't say I've seen one that isn't though.

Image

Portable generator

Posted: Sun, 10 Nov 2013, 06:27
by neilg
This is the RAC generator taken at the Electrokhana this year.
Unfortunately you can't see the ICE details.

Image

Neil

Portable generator

Posted: Sun, 10 Nov 2013, 07:17
by acmotor
So Honda motored generator igx390 11.7 HP (8.7 kW) @ 3,600 rpm so feeding a 6.5kVA alternator giving around 5kW at 3,000RPM ?

Trailer made in Qld
RAC WA presentaion
SA plates....
Did Mitsubishi supply the package ?

Shame on RAC WA for not changing the rego to WA.... or do they own it or is it still owned by Mitsubishi or something ? Maybe RAC are not prepared to buy the charge trailer at this stage ? Could be worth $5k. Just wondering.

I guess the idea is to provide 1kWh of charge to a stranded EV so it can drive (a gentle) 10km. That would take 25 minutes or so at 3.3kW on J1772.
They could do the same with a battery and inverter in the back of the normal RAC service vehicles (e-jerry can style)... The RAC service vehicles probably already have extra 12V battery fitted that they use for lighting and ICE jump start cables.
That way every RAC service vehicle could rescue EVs without the need for a trailer !!

For now, I guess if they knew it was a flat battery EV making the callout then they could go back to the depot and hitch on this trailer.
Me thinks this solution may not take off. Image

edit: spell it right

Portable generator

Posted: Sun, 10 Nov 2013, 15:39
by offgridQLD
It's a nifty concept but the reality is. Most likely it would just be essayer to flat bed the car. All the hassle of purchasing and maintaining that little trailer. They could just turn up with a normal car trailer and tow the car to a mains powered charger. Most likely just as quick and about the same fuel cost.

Or as I first mentioned just call a tow truck.

Kurt

Portable generator

Posted: Fri, 16 Jan 2015, 14:47
by zzcoopej
acmotor wrote: Just a little update...
I tried one of these the other day.

specs:
Max Power Output: 1.5kW/ 2kVA@0.8cos
Rated Output Power: 1.5kVA @0.8cos / 1.2kW
Frequency: 50Hz
Rated A.C Output: 240V
Rated D.C. Output: 12V / 4A

It couldn't charge the iMiEV even at 6A (1500W) with this gen (via current selectable EVSE) . It would start the charge but then the gen would actually shut down the motor after 15 seconds.

So quoted gen power is not always up to the mark !


Hi AcMotor,
I have no real reason to charge my iMiEV with a genny apart from the fact of having an iMiEV and a EU20i from my caravan days, and maybe getting caught out at home with an extended blackout after a storm.
The EU20i was specifically bought as it could just run the caravan's A/c with its high motor start demands. EU20i is good for 1600W continuous, and when I was charging the iMiEV at the shopping centre the other day and demo'd Canion to another owner, I noticed the iMiEV was only drawing about 6.2A (ie 1500W). I have a 2010 iMiEV that always draws <10A on normal charge, so I'm guessing the charger has a charge profile that varies the current over time? The batt was about 2/16 bars when I saw the 6.2A going in and I would assume it would start higher and drop as the battery nears full, or is the higher charge rate closer to full? (Is there a graph of this, I assume I could get Canion to do this if I left it connected during a charge?)
I guess my question is whether you think any damage can be done to the iMiEV charger or battery to try it (I'm guessing not as otherwise you would not have tried a few genny's yourself)?
Also I think I saw in another post that I need to modify the Neutral to get the iMiEV to charge from ANY genny, is that your finding?

Portable generator

Posted: Fri, 16 Jan 2015, 15:48
by acmotor

Canion monitors the DC current going from the onboard charger to the battery pack. The data for this comes from the battery management system current sensor(s). ( there is a coarse and fine sensor so I am lead to believe )
Canion does not monitor the 230V AC mains current input to the iMiEV via the J1772.
So. The 6.2A is DC at the pack voltage, probably around 330V at the time you were looking. This gives about 2079W, that is approx 10A at 230V (2300W) less charger losses. So charger around 90% efficient.
Charge remains at this level until pack is at 100% charge if cells are balanced, before tapering off.

The IMiEV will not charge off 1600W cont EU20i via standard 10A EVSE the like. I have tested an EU20i.
The iMIEV does charge off EU20i via a selectable current EVSE that can select 6A AC charge, assuming the iMiEV J1772 has been monified for full pilot signal function. Check around on forum for reference to this.
Edit .... Don't confuse those two 6A numbers.

Edit: yes, neutral must be connected to earth (pin at least) for EVSE to function. It is both an electrical standards requirement and an EVSE test since you cannot test for earth leakage without an earth to neutral connection at the power source or switchboard. Don't confuse earth with terra firma. Earth in electrical terms is that third wire that should connect to any exposed conductive surface and referenced to terra firma.

Portable generator

Posted: Fri, 16 Jan 2015, 16:23
by zzcoopej
acmotor wrote:
Canion monitors the DC current going from the onboard charger to the battery pack.

So. The 6.2A is DC at the pack voltage, probably around 330V at the time you were looking. This gives about 2079W, that is approx 10A at 230V (2300W) less charger losses.


Of course, that makes heaps more sense!
acmotor wrote:
The IMiEV will not charge off 1600W cont EU20i via standard 10A EVSE the like. I have tested an EU20i.


Thanks, that was much easier than testing it myself! How do you have access to so many gennys?
If I get a 2nd charge cable I guess a selectable current EVSE would be a good choice then if they are not too much more than standard.

Portable generator

Posted: Sat, 17 Jan 2015, 00:28
by acmotor
Unfortunately, unless you go DIY for an EVSE, the present selectable current EVSEs can be $700 or so e.g. Chargeamps unit that I use. charge-amps.com Sweden.
Any J1772 EVSE can be modified by way of the 1kHz pilot signal mark space ratio.... If you are into electronics.

I am a genset junky. From 450W two stroke to 650kVA V12 twin turbo. Sad really.

Portable generator

Posted: Sun, 18 Jan 2015, 23:29
by markrmarkr
I bought this Generator with the hope of being able to charge when pushing extreme range. This 7KVA Generator should give 5.6KW continuous. This should be enough to charge two cars simultaneously.

Before doing anything I did some measurements. The voltage is always 240V not 220 or 230. This means one car using a 10A EVSE should get 2.4KW. Also the earth floats at 120V - halfway between Active and Neutral.

I tried it with a small radiator - it drew 1.2Kw and worked fine.

I didn't mess with tying the earth and neutral together but just plugged my Leafs 10A EVSE in. The Leafs 10A EVSE works fine. So the Generator can provide 2.4KW.

I then tried it with the 32A EVSE purchaseed from Patrick, which I normally have mounted on the wall in my carport. I know - it's not good form to put a 15A plug on a 32A device, but the Leaf will only draw 15A max, and I'm just trying to work out what is possible at this stage. Anyway I got an overload message on the Generator after 5 seconds. The Generator continued to run but voltage went to zero after 5 seconds. This was a bit disappointing as 15A at 240V is only 3.6KW, which I'd expect would be fine on a Generator which can do 5.6KW continuous.

Then I tried a the 10A EVSE with the small radiator together. This should draw 2.4+1.2=3.6KW the same as the big EVSE. However this also gave an overload message after 5 seconds and dropped the voltage to zero.

I don't think there is any earth issue, or if there is it's not the reason things are not working. I think the Generator though able to provide 2.4KW is just not up to providing 3.6KW. I'm only getting about half the advertised continuous power output. Not happy. I'm thinking about trying to get my money back.

Mark

Portable generator

Posted: Mon, 19 Jan 2015, 00:16
by offgridQLD
The funny thing is you see little generators the size of a large microwave with 7-8 kva in the specs . where I have a 8kva generator kubota j108 (genuine 8kva generator) and it's about 300kg and 1m x 1.5m box with a 3cyl diesle powering it.

It's a bit like audio amplifyers rated at 1000w and they never state the distortion (funny how a 80w Yamaha amp has more grunt and less distortion) Image

Kurt

Portable generator

Posted: Mon, 19 Jan 2015, 03:47
by antiscab
I think Goombi had a similar experience, the rating didn't remotely match what the genny could actually do

interesting that in the ad it states max 5kVA, then further down it lists 7kVA 5.6kW

I think the former as actually max continuous load, with the later being max surge rating

I would be inclined to take it back if you are still able, if it doesn't do what you need it to do, being as it is being supplied not as described

Portable generator

Posted: Mon, 19 Jan 2015, 04:37
by acmotor
That unfortunately is typical of the domestic generator market..... vast over claim of capacity.

If you can believe the specs at all, look at the 299g/kWh and 16L tank for 8.5hrs. This will be for motor kW output (not at socket) so reduce by 80% for alternator efficiency and 90% for pure sine inverter (guess) along with fuel at SG maybe 0.8
That works out at .299 / .8 L /kWh at the motor /.8 /.9 = 0.52L/kWh at the socket. Now if the gen was running at '5.6kW' full load then the fuel burn would be 2.9L/hr, with tank of 16L that gives about 6 hours not 8.5, maybe the 8.5hrs is not stated as being at full load ?
Given this, the gen capacity could be more like 16/8.5 = 1.88 L/hr, so 1.88/0.52 gives 3.6kW. Interestingly pretty well what you got.

The is also a clue in the petrol motor size of 269cc.
Typical small 4 stroke motors of this size may produced 5kW at the shaft. Once again, x.8 x.9 alternator and inverter efficiencies and at unity power factor (like your EV) this gives 3.6kW.

It will be the inverter itself that is performing the shutdown. There is a chance that the setting is a bit low, but given the motor as above is probably correct.

http://www.dealsdirect.com.au/fuji-micr ... generator/
gives another take on the same gen.

You would be quite entitled to return the gen as it simply does not produce the power claimed.

To operate this generator without an RCD is actually not Approved, despite the Approved claim in the advert (then they state only the sockets and not the gen are approved ;). To operate it with an RCD requires the neutral to be connected to earth if the RCD is at the gen or connected somewhere in the wiring from the generator. If the EVSE is the only possible load and, as it contains an earth leakage detection, then that is suitable provided the earth connection is made. Beware, there is also risk of damage to the charger in the EV if the generator is floating and not earth referenced not to mention electrocution.

Kurt is right. There are generators and there are generators.

Portable generator

Posted: Tue, 20 Jan 2015, 02:32
by markrmarkr
Thanks for all your input, but I'm not quite ready to face reality yet.

I'm thinking of taking the air-cleaner off, and taking the muffler off, and maybe even giving it a wif of Nitrous Oxide (no that won't work - it takes hours to get a reasonable charge, and Nitrous Oxide is expensive, but you get the idea).

The engine seems to bog down before it trips to overload. So I'm thinking that if I can give it some help, and stop the bogging, the the rpm will stay high under load, and it'll meet the power output requirements.

It's such a nice little generator. With a bit of ingenuity, I can actually get it into the back of my Leaf, where it fits snugly. - I can't just give up on it.

Portable generator

Posted: Tue, 20 Jan 2015, 02:39
by acmotor
Remember that if the gen has an eco switch then turn it off. This gives the motor max revs before the load comes on.
That gen will charge EV at 10 amps of course.