adeyo
Posts: 5
Joined: Thu Jun 06, 2013 8:24 pm
Delivery Date: 0- 0-2013

Re: Onboard inverter

Mon Jun 24, 2013 4:40 pm

fooljoe wrote:
adeyo wrote:would it ever be possible to use a "Sunny Boy" sma inverter (the SB8000US accepts a dc voltage b/w 300-600 volts and spits out 240 volts AC) to power items in my home?
Yes, that should be possible, with the caveat that it's probably a grid-tied inverter

You'd just have to access the main DC lines to the battery (which I believe you can find connected to the charger - but please don't mess with that if you don't know what you're doing). And I think the car would have to be on.
adeyo wrote:For that matter, one could theoretically use the sunny boy to charge the leaf directly via Solar Panels feeding into the inverter -just like a solar battery bank and then when needed, take that power back for home use during the night?
...And if you're talking about a standalone inverter, I'm guessing the Leaf's charger would not be happy with the wildly fluctuating power that would be produced by your solar panels, but again I'm not sure about that.

Anyway, the next question is why would you want to do this?

Thanks for the insight!!! ok, i have some follow up comments/responses to your questions...

1. "i'd have to access the main lines of the DC battery" ....ok, i didn't realize it would be accessible to access the main battery lines. That opens up a few options. (not that i have an approach in mind)

2. "leaf wouldn't be happy with wildly fluctuating power..." that is my presupposition exactly. I'm wondering however, if , using a real charger (some chargers accept DC current) if i could go directly from the DC Solar panels (which might produce 250 Volts (a total of under 6kw -but fluctuating, i understand) and into a charger that accepts DC but that regulates the charge to work with the Leafs BMS (say the quick charge port on the leaf only accepts a constant 230v with 25 amps) ...then i could charge the leaf as long as my charger can put out a minimum constant 230v w/ 25 amps).

3. "why would i want to do this?" I would want to do this because I wouldn't need to buy a separate battery bank for the occasional off grid usage. i.e. power outage etc. Instead, i would charge the leaf during the daytime and use the inverter (12v) battery during the nighttime to power a few essentials: well pump, refrigerator. I am currently grid tied, but this would enable me to "island" in a round about sort of way in emergencies. People have already used their leaf to power such essentials in a storm -the 24kw battery actually recharges the 12v accessory battery and lasts about 2-3 days of use. If i could charge my leaf in an outage, then my runtime for essentials could theoretically go on indefinitely. I could also use a few more items during that time. (also, there are inverters with higher outputs that can be utilized with the leaf.)

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planet4ever
Posts: 4674
Joined: Sat Apr 03, 2010 9:53 pm
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Leaf Number: 1537
Location: Morgan Hill, CA, south of San Jose

Re: Onboard inverter

Mon Jun 24, 2013 6:52 pm

adeyo wrote:say the quick charge port on the leaf only accepts a constant 230v with 25 amps
No, that is nowhere close to what the QC port accepts. That port is logically connected directly to the battery terminals, so the DC voltage needs to be in the neighborhood of 400v. Someone correct me if I'm wrong, but it seems obvious to me that the voltage must also be adjusted dynamically by the external charger to yield the current that the car demands. We are talking E = I*R here, where R is (largely) the battery resistance, which varies with charge, and I is a number communicated through the CHAdeMO interface that also varies with charge (and probably battery temperature). The external charger would have to continually monitor the current, and boost or ease E to yield the proper I.

This is way beyond plugging in a solar array output and hoping, or even using an intermediate charger with a constant voltage output.

Ray
End of April 2013: Traded my 2011 SL for a 2013 S with charge pkg.

adeyo
Posts: 5
Joined: Thu Jun 06, 2013 8:24 pm
Delivery Date: 0- 0-2013

Re: Onboard inverter

Mon Jul 08, 2013 7:31 am

planet4ever wrote:
adeyo wrote:say the quick charge port on the leaf only accepts a constant 230v with 25 amps
No, that is nowhere close to what the QC port accepts.

This is way beyond plugging in a solar array output and hoping, or even using an intermediate charger with a constant voltage output.

Ray
just made up those numbers for the theory :) ...so basically the car cannot accept a constant voltage/amperage to its battery and expect to charge at all -quickly or slowly?

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