adjustable 240vac EVSE?

I am considering getting a third EVSE. The reason is I would like to be able to use our excess solar power to charge the car and my inverter is rated at 6 kw so even with the minimal house loads I have no room left to run the clipper creek HSC-40. I have been using the trickle charger, but it doesn't pull enough power I would rather charge even at 10 amps at 240vac, sometimes up to 15 amps at 240vac.

I understand the EVSE upgrade unit can be adjusted, but how difficult is that to do on the fly? Are there any other options, ie wall units, which would let you choose an output level?

I am guessing the least expensive way would be to get an EVSE upgrade, but looking further down the road, potentially having 2 BEV's, maybe another adjustable wall unit makes sense?

So what other adjustable units are out there?

I am working on a similar project with OpenEVSE.

I am measuring solar output with Open Energy Monitor and uploading the data to emoncms.org.

On OpenEVSE I poll the data and adjust the pilot dynamiclty every 5 seconds to suck up as much solar as possible.

Here is an old view of my energy. I will post s solar/evse with dynamic current view soon...

I have made my dashboard Public. The dashboard can be viewed here:
http://emoncms.org/chris1howell/

The one I'm using (the Home Depot GE DuraStation that goes for $450) has a jumper to select the amperage in 6A increments. I think the selections are 12A/16A/24A/30A.

hmmm I had't even thought about making it automatic. Right now I have the solar controller absorb signal powering two heavy duty relay's. Both powering 1500w water heater element's (upper and lower) in the 80 gallon pre-tank. When it gets the signal from the absorb mode, it turns on one element for 5 minutes and the second element for 10 minutes. The 10 minute one stays on pretty much all the time when it's sunny and the 5 minute one cycles on and off depending on battery state. I wonder if I could do the same sort of thing except turning on the EVSE.

BrockWI said:

... I wonder if I could do the same sort of thing except turning on the EVSE.

Click to expand...

If you do, try to switch the pilot signal off and on rather than simply cut power to the EVSE. The car considers cutting the power to be an error. If you have the wiring and computer skills, you could build an OpenEVSE, and modify the software to accept a power level over the serial port, and adjust it on the fly...or you could at least have it monitor an input and do the switch on and off in response.

Anyway, why bother with all this? If you net meter, it all comes out in the wash. It might make sense if you are all the way off the grid since charging a storage battery only to then charge the car from it wouldn't be very efficient.

There is the rub, no net metering here, as a matter of fact if I do "sell" back to the grid the meter records it as consuming, no matter the flow of power. So I can't be in "sell" mode or I will get charged for my excess power sent back to the grid. Fortunately or unfortunately at the same time we produce most the solar power we are at high peak rates, so if I sell in that situation to off set my current EVSE 6 kw load and say only use 3 kw from the grid and 3 kw from solar I am paying four times as much for that power or that 3 kwh would cost he same as 12 kwh at night.

So I have to try to "use" the power when I make it and I would rather put it in the car than heat water

davewill said:

BrockWI said:

... I wonder if I could do the same sort of thing except turning on the EVSE.

Click to expand...

If you do, try to switch the pilot signal off and on rather than simply cut power to the EVSE. The car considers cutting the power to be an error. If you have the wiring and computer skills, you could build an OpenEVSE, and modify the software to accept a power level over the serial port, and adjust it on the fly...or you could at least have it monitor an input and do the switch on and off in response.

Anyway, why bother with all this? If you net meter, it all comes out in the wash. It might make sense if you are all the way off the grid since charging a storage battery only to then charge the car from it wouldn't be very efficient.

Click to expand...

OpenEVSE has mechinisms for both through the remote API to support going into sleep (pilot high) and dynamicly adjusting the current.