Are you able to drive an EV while its being charged?

[alohaspirit]

I was hoping you would chime in

so the ForkenSwift uses 1200 watts.
is this a common consumation number?


is a Honda EU2000iA
2000 watts. Noise: 43/49 dB. Weight: 46 lbs.
9.6 hours on 1 gallon.
but it does cost over $1k
(im sure we could find a used one cheaper)



at least i have more info to stoke the fire with


1. What if i run out of power in an EV?
(can i plug in and continue driving?)

A: Yes. But only for intermittant driving as the batteries charge slowly.


2. What if i want to drive father than the range will allow?
(again, can i plug in and continue driving?)

A: Yes. But only for intermittant driving as the batteries charge slowly.



The best thing you can do is if you run out of juice is to find a rest stop.
Plug your generator into your vehicle and take a break.
After a while, get back in and continue on your way.

The time spent waiting is only determined by how fast your batteries charge.





Which of course opens the floor to another question.
Quick-charge charger/batteries?


12 min charging time (naturally made for the EV1)
Quick Chargers for Electric Vehicles

[todayican]

This conversation is like music to my ears! :-)

Ill be doing something similar with Belaero, except in DC.

The main pack will be about 5KWH and drive engine will be the new "poppa Etek" and the gen will be an efficient little 7hp ICE (possibly graduating to a 10hp diesel) the ICE will turn a smaller ETEK to output about 6hp (from the gas engine) and 9hp (form the diesel) either one should power the car at speed.

The 10hp would likely also turn an alternator for the 12v and possibly even an AC compressor.

Approximate price for the Gen:

7hp ICE electric start $300
little Etek $500
Fab and mounts $100
Total $900

Diesel $700
Little Etek $500
Fab and mounts $100
Total $1300

Anyone want me to build them one too :-)

[todayican]

Aloha, I read your post again just now and I think there is a flaw in the logic.

* Quote *
1. What if i run out of power in an EV?
(can i plug in and continue driving?)

A: Yes. But only for intermittant driving as the batteries charge slowly.


2. What if i want to drive father than the range will allow?
(again, can i plug in and continue driving?)

A: Yes. But only for intermittant driving as the batteries charge slowly.
* End Quote *

If the vehicle is driving and using the amps as they come form the Gen your not so much charging the batts for future use, your using them as a "pass through entity" so (assuming the gen is matched to the amp draw of the vehicle at whatever speed your driving) youll get to where your going but still have low batteries.

Now, assuming some sort of "dc charge controller" is in place, you could just leave the gen on while your doing whatever it is your doing at your destination if you like.

Do I have this right?
Tom

[MPaulHolmes]

Hi Sawicki! Yes, the charger, controller, and bms all speak to each other over CAN. The BMS keeps telling everyone what the voltage of every battery is. The controller keeps a running total of the amp*hrs used since last charged. When the pack drops to 50% or so, the charger is informed about this. A relay providing 12v power to the electric start kicks in by the controller. Then, the precharge sequence starts up for the charger, which has 3 relays. One to precharge the input cap, one to put the battery pack in the charger circuit, and one to close the contactor to put the 220v AC power into the circuit with the charger. Then the charger ramps up to the constant 6kW load. If the batteries somehow get fully charged while still driving, the plan is to just stop charging, and not worry about balancing the pack until you are no longer driving around. All this info is just a bunch of numbers sent in packets over CAN, so it's not as hard as it sounds.

The batteries are Thundersky, so they can handle charge rates of around 270 amps, since they are 90 amp*hr, and are 3C rated for charge and discharge. The actual charge rate I hope to be around 50 amps. We'll see how the poor power factor of the charger affects the generator. I think it will be OK. I was able to charge at 72v and 20 amps without the circuit breaker blowing, and it was a 15 amp breaker. Heck even at 30 amps it took a while for it to trip.

You coudl have the option of putting the car into eco mode so that it doesn't allow more than 50 battery amps so you could drive until the gasoline ran out, or you could set it to x battery amps, and then the 50% would then still drop (but more slowly) but you could extend your range until it reached 20% or whatever depth of discharge you like.

[MetroMPG]

Originally Posted by alohaspirit

so the ForkenSwift uses 1200 watts.
is this a common consumation number?

Unfortunately, no. Chargers vary in power consumption/output.

But you could generalize: it's likely that the max power used by a 110v charger is 20A * 110v = 2200 Watts. (Assuming 20A is the max common breaker size on 110v circuits).

The time spent waiting is only determined by how fast your batteries charge.

That's about it. Should say however, that at least with lead-acid batteries, you can get an 80% charge much faster than you get 100% charge. Meaning: much more time is spent going from 80-100% than getting to 80%.

I'm waiting for Paul to chime in again. He's talking about a 6kW genset. So obviously he has other plans than my example. His & todayican's examples are examples where the genset can theoretically provide all the juice the electric motor needs to propel the car. So they could drive indefinitely (or until the gas runs out) :P

But I think my example is close to what I think you were asking: "could I theoretically go to the hardware store right now, buy a portable generator and connect it to my existing battery charger, effectively making the car a plug-in hybrid in 5 minutes?" Answer: yes, with the limitations that you get.

[todayican]

One thing I was thinking was, during "drive mode" for the gen (If its a dc gen anyway) one could bypass the batts and controller alltogether, gaining whatever efficiency might be lost on the controller itself and just drive the traction motor with the gen and modulate the gens throttle to adjust speed.

Dont know what the greater of the evils are in this scenario, running through the batts and charging them with whatever isnt being used by the drive motor at any given time, and accepting the electrical efficiency losses of the controller etc, or modulating the throttle of the gen and potentially not having it in its peak efficiency curve (a BIG advantage with serials I beleive)

Something else to make it even more interesting...

Ill be using 60ah thundersky batteries and asking as much as 7.5c from them during full power acceleration (possibly too much, need to do more research)

What if, I limited it to 380a max from the battery pack alone and if I really need a lot of amps, (going up a big hill, etc) add the gen in for the full 450 so the batts would not have to put out more then 6.3c on their own?

So much new ground here... :-)

[alohaspirit]

The only thing is that if you constantly charge to 80%
it lessens your batteries ability to charge to 100%
(shortening the range)

[MPaulHolmes]

Controllers are probably 99% efficient. If you think of the batteries as a huge water storage tank, and you open up the pipe for the water to start pouring in as fast as possible, if you are at a stop light, the water is filling up. If you want to do some hard accelerations, the tank drains some. If you are happy to keep the batteries at 50% or whatever, I think you could eliminate the controller. It could simplify the system a little bit, but you would be forced into unforgiving eco mode, rather than having it as an optional "average eco" sort of thing.

The parts for the 0-192v 0-50amp charger are around $400, excluding the 50amp 2mH inductor. I have no idea what one of those costs.

[todayican]

I think the controller will always be needed in a road going car (barring some sort of contactor arrangement) to take off and reverse etc.

[Clev]

Originally Posted by todayican

One thing I was thinking was, during "drive mode" for the gen (If its a dc gen anyway) one could bypass the batts and controller alltogether, gaining whatever efficiency might be lost on the controller itself and just drive the traction motor with the gen and modulate the gens throttle to adjust speed.

You probably don't want to do that. You'll either need to massively oversize the generator (reducing efficiency), or continually switch from gen to controlller whenever you need to accelerate a little bit.

Ill be using 60ah thundersky batteries and asking as much as 7.5c from them during full power acceleration (possibly too much, need to do more research)

What if, I limited it to 380a max from the battery pack alone and if I really need a lot of amps, (going up a big hill, etc) add the gen in for the full 450 so the batts would not have to put out more then 6.3c on their own?

I remember this conversation from the EVDL, and I seem to remember them saying that whatever extra the generator provides reduced the load on the batteries. So if you are pulling 7.5C at the controller, but pouring in 2C from the generator, the batteries see it as a 5.5C load. So yes, this would work.

You want to figure out what your cruising consumption is, and then try to size your generator to put out that much, plus a few percent to cover acceleration, hills, etc. That way, your generator is sized to its maximum efficiency. At best, it will have to cycle off occasionally (if you have a tailwind), and at worst, you may have to stop occasionally on a long drive (if you have a headwind) and let it charge for an hour.