Charging on battery storage with solar charging

[jackphillips1953]

Has anyone attempted to build a stand alone off grid solar charging station for charging an EV? I have 4 solar panels that I use in the summer that are connected to pool pump for filtration. I have been using for 7 years with no issues here in NJ. During the winter they lay around no doing much. I was able to acquire 15 100 amp hour AGM batteries that were used for solar monitoring applications. I am able to use for some out door projects such a lighting pond filtration but it is really a waste not to be able to use for something better. I tried connecting to my 1500 watt inverter with no load to the EVSE provided in the car but I get a red light. The system is grounded properly. Question is if any one has tried this, what inverter are you using? Thanks.

 

[DucRider]

Oregon State University has a Solar Trailer they bring to events. We have had it at our Drive Electric Week event the last few years.

Solar Trailer specifications:

1800 watt solar array - nine Sanyo 200 watt solar modules
Two 3.6 kilowatt Outback grid interactive inverters capable of 7.2 kW (60 Amps @ 120 Volt or 30 Amps @ 240 Volt)
About 25 kilowatt hours of battery storage in an advanced lithium-ion battery pack, with a custom battery management system installed by Shift Electric Vehicles in Albany, Oregon
One SAE-J1772 Electric Vehicle Safety Equipment (EVSE) charging system
Two 20 amp 120 volt circuits feeding 4 standard 120V household outlets
One 30 amp 240 volt circuit powering one dryer style outlet
Wattsun dual axis sun tracker
Expandable, fold out array
Mechanical lift moves array into sun tracking position

http://fa.oregonstate.edu/sustainability/operations/energy/renewable-energy

https://www.facebook.com/OSUSolarTrailer/

At this years event powering the Nissan display tent

 

[JeffreyDV]

Four panels aren't nearly enough to power the EVSE. You would need 1440 watts just to run it never mind conversion loss through the inverter and wiring. I would say 10 panels of at least 200 watts each would be the minimum.

 

[DucRider]

Four panels aren't nearly enough to power the EVSE. You would need 1440 watts just to run it never mind conversion loss through the inverter and wiring. I would say 10 panels of at least 200 watts each would be the minimum.

That's why it has a 25 kWh pack.
No it won't continuously supply an EVSE, but shows the OP that using batteries to store your solar energy and then powering an EVSE from them is possible and has been done (which was his question).

 

[Maxters]

Start googling around with grounding/neutral bonding on EVSE and charging on generator.

This subject has come up in the My Nissan Leaf .com side of this website with mixed results.

http://www.mynissanleaf.com/viewtopic.php?f=26&t=5792&start=40

See if that gets you going the right direction.

 

[jackphillips1953]

Thanks for all the help. I believe it is a grounding problem. I am not looking to completely charge the Bolt. Partially maybe. I just wasting these panels over the winter and would like to use some of the energy somewhere. maybe the ground is the problem. The inverter has ground fault built in, but does not ground. Anyone ever play around with this?

 

[JeffreyDV]

Four panels aren't nearly enough to power the EVSE. You would need 1440 watts just to run it never mind conversion loss through the inverter and wiring. I would say 10 panels of at least 200 watts each would be the minimum.

That's why it has a 25 kWh pack.
No it won't continuously supply an EVSE, but shows the OP that using batteries to store your solar energy and then powering an EVSE from them is possible and has been done (which was his question).

DucRider,

I was replying to the OP who stated he had 4 panels. The picture you posted shows 9 panels.

 

[oilerlord]

Thanks for all the help. I believe it is a grounding problem. I am not looking to completely charge the Bolt. Partially maybe. I just wasting these panels over the winter and would like to use some of the energy somewhere. maybe the ground is the problem. The inverter has ground fault built in, but does not ground. Anyone ever play around with this?

Do you have an existing solar array you could hook up the PV modules to? You could explore going the AC coupled route (if you want to use the batteries) for the added benefit for a whole-house UPS but I think you're looking at sinking a lot of dough & fussing around for not much payback.

 

[jackphillips1953]

Definitely a ground issue. I grounded inverter to ground and checking shows grounded properly. Still get red light on charger. Makes no sense. Could it be a ground fault built into inverter causing the problem? This is just playing around and using these panels which go to waste 7 months of the year. I have a grid tied 10kw system for 8 years now so not a big deal if I cannot get up and running but would be nice.

 

[JeffreyDV]

I'm guessing the inverter is too small or you need a pure sine wave inverter to run the EVSE.

 

[ProfessorBolta]

The Bolt manual states to not charge of anything other than grid (no generators specifically). All inverters have some degree of noise and hash on the output power supply, and various degrees of power factor correction the Bolt may or may not like.

One experience, at my workplace they placed the free EVSE's on the solar panel array/inverter side of the grid. For accounting reasons basically, that way it wouldn't have to get billed to a department. Anyhow the industrial inverters (which you would think would be pretty clean) produced so much hash it interfered with many of the cars. We had a large sample of different cars experiencing this, due to the various employees and the cars they had.

So preferentially plug in to the grid for good, clean energy.

 

[Marktm]

Has anyone attempted to build a stand alone off grid solar charging station for charging an EV? I have 4 solar panels that I use in the summer that are connected to pool pump for filtration. I have been using for 7 years with no issues here in NJ. During the winter they lay around no doing much. I was able to acquire 15 100 amp hour AGM batteries that were used for solar monitoring applications. I am able to use for some out door projects such a lighting pond filtration but it is really a waste not to be able to use for something better. I tried connecting to my 1500 watt inverter with no load to the EVSE provided in the car but I get a red light. The system is grounded properly. Question is if any one has tried this, what inverter are you using? Thanks.

Some inverters (smart UPSs as an example) have "floating ground" on the outputs and will throw a "ground fault" error when switched to battery power (shows on my OpenEVSE's LCD screen). It will not charge my EV unless I disable the ground fault detection when running on solar/batteries. The case of the UPS and the OE's ground wiring are all earth grounded, but makes no difference as that ground is isolated from the L1/neutral wiring on the receptacle. In "normal" US wiring the neutral and ground are connected at the main panel - likely the difference.

If you can try an Open EVSE CC, the menu system will allow turning off the ground fault detection - however, there could be some risk in that if you have an actual short to ground without proper breaker/fuse protection.

I tend to agree that you need to either "batch" the charge with the batteries (a real pain), or get many more panels. There has been some good research on the efficiency of charge at low rates - it is quite a bit worse than at high charge rates and is not good at best!

 

[jackphillips1953]

Thanks for all the help. Putting back burner until spring. I like the inverter needs upgrading and I need see if worth it. Now using these panels to charge 15 (AGM) 100 amp batteries and using that power for outside lighting.