Onlooker
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Joined: Wed Dec 14, 2016 2:49 am
Delivery Date: 14 Dec 2016

Directly charging Leaf with Solar Panels...

Thu Jan 05, 2017 8:06 am

Hi, I read a lot of other topics in this area about charging the Leaf with solar, but I felt all the replies and or posts sort of missed the angle I would like more information on.

Not that it's important to questions, my situation/needs:
I am off-grid now with just under 2KW solar in the far north east... My usage would be 25 miles every 2 days with occasional round trips to 50miles.

Being budget oriented(I use $200 1000W PSW/3000W-MSW inverters and plenty of 12VDC) off-grid in an area with lousy sun I am keenly aware of efficiencies and losses and have done real world tests that contradict popular opinion and even device specifications with converters/inverters/controllers. 84-95% efficient inverters I find have a 30% loss usually unless the power draw is in a very narrow range(rarely at).

Several of the Leaf's I'm looking at have a level3 440VDC charging port. Does the Leaf itself have a controller to handle the level 3(440vDC) charging? I presume it does, as the communication/complexity needed for the other way around would be unlikely...

If a Leaf has a built-in controller is there a way to safely(from an electronics in the leaf standpoint) connect an array of solar panels directly to the 440VDC charging of the leaf? ie: Is there a wide working voltage range on the fast charge port?

What I'm thinking might be a nice way to go is install a new array for the leaf(sure I can divert power besides that but for purpose of Leaf capabilities)...

Say for example I use 225W 30.36V Vmp 36.43Voc ; 7.41AImp solar panels:

14 in series(and quite possibly 2+ of those in parallel to drive up amperage)
for 425V under load; and 512Voc. Is the leaf charge controller smart enough to take a wider range of input DC voltage and handle/test higher voltage open circuit voltage? ie: Some controllers may test voltage and see > 500V and shut itself down for safety(over voltage); What the 'overvoltage level is in the Leaf could allow direct panel connections.

I don't want expensive/proprietary/wasteful equipment between the leaf's charge controller and solar panels. Just a dumb old ~400-500VDC solar plug waiting for a device to accept power.

Any details/thoughts from those with a better idea of the Leafs internals?


Example of why I don't want inverter charging...
Panels -> MPPT (5-10% loss) -> Inverter(25% Loss) -> Leafs Charge(Likely 25% Loss)
Then more trouble still in such a system for having house/inverter batteries connected and needing something in place to not attempt to charge leaf until house batteries are fully charged and stop when panels no-longer produce enough to maintain(Don't want to drain house batteries to charge car).
Each 1KWh solar out would turn into ~0.52KWh in the Leaf battery... Pretty lousy.

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Randy
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Re: Directly charging Leaf with Solar Panels...

Thu Jan 05, 2017 12:39 pm

I"m curious how you can go off-grid with a 2 kW PV system and have enough surplus power left over to think about charging a LEAF? What sort of batteries do you have installed?

Onlooker
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Re: Directly charging Leaf with Solar Panels...

Thu Jan 05, 2017 4:06 pm

Randy wrote:I"m curious how you can go off-grid with a 2 kW PV system and have enough surplus power left over to think about charging a LEAF? What sort of batteries do you have installed?


Well as stated I would like the idea of adding a cheap array primarily for the Leaf if it could be charged directly(cut costs significantly vs inverters and conversion losses; would need 2x the size once inverters/etc were added).

Although I confess with my 2KW system and 2KWh/day (or less carefully calculated(efficient fridge/24hr computer, lights, fans, pumps, washer,microwave, etc)) household usage I've broken 7KWh on sunny summer days just trying to waste power(and could likely squeeze a bit more out) running AC and Digital Pressure cooker/fans. With me needing to drive so little(35km every 2(2.5) days) most of the time and the idea of 0.212 kWh/km.. 35*0.212= 7.42KWh / 2 = 3.71KWh/day it's a bit of a novelty idea of making due with the existing system(for 6 months anyway).

Currently I use a 12V forklift battery; highly recommend(most KWh through them for the $ of any currently available battery, golf cart batteries are junk).

If the leaf could be charged directly, it also poses an interesting option of using the car's DC-DC converter as a secondary 12V power source(since I use so little), especially if one could find a hack to get the converter working without the car itself/overall being 'ON'... It is my understanding the car simply ON uses over 100W which adds up quick over hours/days.

Levenkay
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Location: Portland, OR

Re: Directly charging Leaf with Solar Panels...

Thu Jan 05, 2017 7:13 pm

Onlooker wrote:Several of the Leaf's I'm looking at have a level3 440VDC charging port. Does the Leaf itself have a controller to handle the level 3(440vDC) charging? I presume it does, as the communication/complexity needed for the other way around would be unlikely...

If a Leaf has a built-in controller is there a way to safely(from an electronics in the leaf standpoint) connect an array of solar panels directly to the 440VDC charging of the leaf? ie: Is there a wide working voltage range on the fast charge port?
I believe the CHAdeMO charge port just gives the external charging supply a direct connection to the vehicle's battery terminals (through a suitably robust contactor relay). The port's CAN pathway provides details about charging current and voltage limits, I believe, and possibly battery temperatures. I suspect the LEAF's battery controller updates those settings as charging progresses, and probably has a way to tell if the external equipment has gone berserk and can drop out its contactor if necessary to prevent overcharging (although that action is likely to be pretty violent).

It sounds as if your panel's max output current will probably still be just in the "trickle charge" range, so all you might need would be a way to clamp the panel's voltage to some suitable maximum, a hefty diode to prevent discharging through the panel, an impressive DC high voltage fuse or suitable fault protection, and maybe a contactor for your own side of things. You could set the clamp voltage conservatively, and accept that the charger wouldn't get you all the way to 100% unless you go to the effort of tapping into the port's CAN and extracting the necessary info.

Just letting the PV panel act as a trickle current source into whatever the vehicle's battery voltage was wouldn't necessarily extract the optimum power from the panel, but you couldn't beat it for simplicity.

You might check outthis video by Jack Rickard; he's recently installed his own PV array dedicated to charging a hefty high-voltage battery pack to supply CHAdeMO car charging sessions from.

Onlooker
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Re: Directly charging Leaf with Solar Panels...

Fri Jan 06, 2017 6:34 am

Levenkay wrote:
Onlooker wrote:Several of the Leaf's I'm looking at have a level3 440VDC charging port. Does the Leaf itself have a controller to handle the level 3(440vDC) charging? I presume it does, as the communication/complexity needed for the other way around would be unlikely...

If a Leaf has a built-in controller is there a way to safely(from an electronics in the leaf standpoint) connect an array of solar panels directly to the 440VDC charging of the leaf? ie: Is there a wide working voltage range on the fast charge port?
I believe the CHAdeMO charge port just gives the external charging supply a direct connection to the vehicle's battery terminals (through a suitably robust contactor relay). The port's CAN pathway provides details about charging current and voltage limits, I believe, and possibly battery temperatures. I suspect the LEAF's battery controller updates those settings as charging progresses, and probably has a way to tell if the external equipment has gone berserk and can drop out its contactor if necessary to prevent overcharging (although that action is likely to be pretty violent).


Yeah, I could see it doing that, but given all the positive reviews about cell load balancing, that suggests to me the Leaf or perhaps the cell packs themselves have built in controllers and carefully throttles the current/voltage to what they need to maintain over-all(This is required for Lithium cells at some degree). The Leafs are starting to enter the used market at prices more hobbyists/tinkerers are going to start to take a look/play. I posted here hoping some engineer at Nissan(or hobbyist) might have the answer(voltage range and or CHAdeMO communications protocol) that would indicate how possible direct solar array to Leaf might be possible. My budget doesn't really allow purchasing to be the first to try(as is often the case with finding power efficient devices), but if I knew providing X resistor/signal between CHAdeMO wires would tell the Leaf itself to start charge cycle and that it could handle XXX-XXX Voltage range... It gets quite interesting.

Levenkay wrote:It sounds as if your panel's max output current will probably still be just in the "trickle charge" range, so all you might need would be a way to clamp the panel's voltage to some suitable maximum, a hefty diode to prevent discharging through the panel, an impressive DC high voltage fuse or suitable fault protection, and maybe a contactor for your own side of things. You could set the clamp voltage conservatively, and accept that the charger wouldn't get you all the way to 100% unless you go to the effort of tapping into the port's CAN and extracting the necessary info.

Just letting the PV panel act as a trickle current source into whatever the vehicle's battery voltage was wouldn't necessarily extract the optimum power from the panel, but you couldn't beat it for simplicity.


That is somewhat the idea... Although 'trickle' even using the hypothetical panels specs mentioned above would peak at 3150 Watts; 2x that of 110V charger; Double up on panels with 2 sets of 14, 6300Watts... Could get rather novel... All this depends on details not readily published, but easily discovered if someone has the money/toys to experiment. One possibility is the Leafs individual cell balancing doesn't takeover until it reaching an 80% charge level and everything would work rather brainlessly up to that point.(which could be fine) .


Levenkay wrote:You might check outthis video by Jack Rickard; he's recently installed his own PV array dedicated to charging a hefty high-voltage battery pack to supply CHAdeMO car charging sessions from.


4GB Video including scenic beginning; My internet is to slow for that just now.

arnis
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Re: Directly charging Leaf with Solar Panels...

Fri Jan 06, 2017 1:18 pm

Without sophisticated ChaDeMo controller it is not possible to charge battery directly using DC solar juice.
Tapping in directly is also not possible as contactors are disconnected.


The only way is to use J1772 and use vehicles onboard charger. Accept inefficiencies. On board and off board.
J1772 accepts 100-240V AC range, 50-60Hz. Using pilot signal it is possible to modify input power requirement.
Short range EVs <30kWh -- Medium range: 30-60kWh -- Long range: >60kWh
Charging: Trickle <3kW -- Normal 3-22kW -- Fast 50-100kW -- Supercharging >100kW

Onlooker
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Re: Directly charging Leaf with Solar Panels...

Sat Jan 07, 2017 6:24 am

arnis wrote:Without sophisticated ChaDeMo controller it is not possible to charge battery directly using DC solar juice.
Tapping in directly is also not possible as contactors are disconnected.


The only way is to use J1772 and use vehicles onboard charger. Accept inefficiencies. On board and off board.
J1772 accepts 100-240V AC range, 50-60Hz. Using pilot signal it is possible to modify input power requirement.


Ah, Thanks; Getting caught up a bit! Theres lots of youtube videos suggesting ChaDeMo controller hacking/bypassing(custom controllers) what seems to suggest it's possible but not as easily as I had hoped. Living with the 50%+- losses using the 100-240V AC charging from a DC Solar source just doesn't seem worth pursuing to me, but I'll keep watching for an affordable ChaDeMo hack that might allow a high voltage solar array to charge a leaf semi-directly(obviously a control board/system would be needed between).

https://www.youtube.com/watch?v=ddKkffUKZWE

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RegGuheert
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Re: Directly charging Leaf with Solar Panels...

Sat Jan 07, 2017 10:17 am

We have discussed the idea of charging the LEAF directly from PV panels previously in this thread.
RegGuheert
2011 Leaf SL Demo vehicle
2011 miles at purchase. 10K miles on Apr 14, 2013. 20K miles (55.7Ah) on Aug 7, 2014, 30K miles (52.0Ah) on Dec 30, 2015, 40K miles (49.8Ah) on Feb 8, 2017.
Enphase Inverter Measured MTBF: M190, M215, M250, S280

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Marktm
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Re: Directly charging Leaf with Solar Panels...

Tue Jan 10, 2017 2:28 pm

Levenkay wrote:
You might check outthis video by Jack Rickard; he's recently installed his own PV array dedicated to charging a hefty high-voltage battery pack to supply CHAdeMO car charging sessions from.


Interesting character - Jack - and interesting "blogs". He has located a supplier of a MPPT functional EV battery type solar charge controller from Sandi Electric Co. that has the voltage range of 600 VDC and that should work with PV arrangements that are more common in the grid-tied inverter installations (at least mine). "Jack" also stated that Sandi can provide a suitable inverter that will operated at the EV battery voltage ranges of approx 400 VDC and produce 240 VAC split phase directly.

Appears his company is assembling a DC/QC system comprised of the PV panels, high voltage CC, Li battery array (similar to Leaf's size and voltage), and a CHAdeMO compatible quick charger that is powered directly by the battery array. By adding the inverter, they will have an "off-grid" home power system along with the EV "quick charger". With enough PV panels, "batteries" and matching high voltage CC's it appears you could go off-grid - including your Leaf ($$$s). Seems worth following!!
2012 Leaf SL; 34,000 miles. 12 bars - Battery replaced November 1st, 2016.
4000 watts Grid-tied solar. 3000 watts (level II) off-grid solar Leaf charging capable.

stifn43
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Re: Directly charging Leaf with Solar Panels...

Mon Jun 19, 2017 3:25 am

Onlooker wrote:Hi, I read a lot of other topics in this area about charging the Leaf with solar, but I felt all the replies and or posts sort of missed the angle I would like more information on.

Not that it's important to questions, my situation/needs:
I am off-grid now with just under 2KW solar in the far north east... My usage would be 25 miles every 2 days with occasional round trips to 50miles.

Being budget oriented(I use $200 1000W PSW/3000W-MSW inverters and plenty of 12VDC) off-grid in an area with lousy sun I am keenly aware of efficiencies and losses and have done real world tests that contradict popular opinion and even device specifications with converters/inverters/controllers. 84-95% efficient inverters I find have a 30% loss usually unless the power draw is in a very narrow range(rarely at).

Several of the Leaf's I'm looking at have a level3 440VDC charging port. Does the Leaf itself have a controller to handle the level 3(440vDC) charging? I presume it does, as the communication/complexity needed for the other way around would be unlikely...

If a Leaf has a built-in controller is there a way to safely(from an electronics in the leaf standpoint) connect an array of solar panels directly to the 440VDC charging of the leaf? ie: Is there a wide working voltage range on the fast charge port?

What I'm thinking might be a nice way to go is install a new array for the leaf(sure I can divert power besides that but for purpose of Leaf capabilities)...

Say for example I use 225W 30.36V Vmp 36.43Voc ; 7.41AImp Solar Panel Maintenance:

14 in series(and quite possibly 2+ of those in parallel to drive up amperage)
for 425V under load; and 512Voc. Is the leaf charge controller smart enough to take a wider range of input DC voltage and handle/test higher voltage open circuit voltage? ie: Some controllers may test voltage and see > 500V and shut itself down for safety(over voltage); What the 'overvoltage level is in the Leaf could allow direct panel connections.

I don't want expensive/proprietary/wasteful equipment between the leaf's charge controller and solar panels. Just a dumb old ~400-500VDC solar plug waiting for a device to accept power.

Any details/thoughts from those with a better idea of the Leafs internals?


Example of why I don't want inverter charging...
Panels -> MPPT (5-10% loss) -> Inverter(25% Loss) -> Leafs Charge(Likely 25% Loss)
Then more trouble still in such a system for having house/inverter batteries connected and needing something in place to not attempt to charge leaf until house batteries are fully charged and stop when panels no-longer produce enough to maintain(Don't want to drain house batteries to charge car).
Each 1KWh solar out would turn into ~0.52KWh in the Leaf battery... Pretty lousy.

Hi
There are many benefits of using solar energy. Solar power is pollution free and causes no greenhouse gases to be emitted after installation. Reduced dependence on foreign oil and fossil fuels. The renewable clean power that is available every day of the year, even cloudy days produce some power.

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