LEAFfan
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Re: How is the 12V battery recharged? Max amperage?

Tue Nov 16, 2010 10:17 pm

danwat1234 wrote:
EVDRIVER wrote:This has been discussed multiple times on many threads. The DC/DC charges the battery, not sure the charge current but it will be high likely. The DC/DC is off when key is off. What does the charge rate have to do with having something on? What type of constant load are you looking to have on all the time. if you give me details I can give you better info. The solar panel generates very little power and just trickle charges the 12V battery.


Well, say if the power is out and I need to plug in my 2 refrigerators, a few fluorescent lights and a few laptops to a 12VDC to 120AC inverter.. The car would be ideal to provide backup power. I guess we will just have to wait a bit until specs are released.


If you decide to do that, you will void your warranty.
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smkettner
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Re: How is the 12V battery recharged? Max amperage?

Tue Nov 16, 2010 10:23 pm

Put a couple AGM batteries or a Honda generator in the trunk and haul them out when needed. I would not be using the Leaf as a tailgate power supply.
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xRB
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Re: How is the 12V battery recharged? Max amperage?

Wed Nov 17, 2010 5:13 am

mwalsh wrote:
danwat1234 wrote:Well, say if the power is out and I need to plug in my 2 refrigerators, a few fluorescent lights and a few laptops to a 12VDC to 120AC inverter.. The car would be ideal to provide backup power. I guess we will just have to wait a bit until specs are released.


Uh, oh. I see someone voiding their battery warranty! :lol:


The battery warranty is so limited and insignificant that a hungry owner would be better off to have the refrigerator still working. :D

danwat1234
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Re: How is the 12V battery recharged? Max amperage?

Fri Nov 19, 2010 12:38 pm

Why would the warranty be voided?
I would just attach a 12VDC to 120VAC inverter to the terminals of the 12v battery, with battery clamps or on the bolts. No warranty issue there.

It would serve as a great temporary power backup, just need to know if the 12v charger can keep up.

As for getting power straight from the pack, well, that would involve splicing wires or something and I would need a special step-down inverter and there is a warranty issue there.

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garygid
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Re: How is the 12V battery recharged? Max amperage?

Fri Nov 19, 2010 1:57 pm

The 12v battery is only "charged" when the LEAF is ON. Then the high-voltage (300 to 500 volt?) DC to 12 volt (nominal) DC converter might be capable of supplying 100 amps (or so).

However, that would be "using the LEAF's (main) battery" as a "power source", which is listed by Nissan as a "prohibited" (or "not covered"?) use.
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danwat1234
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Re: How is the 12V battery recharged? Max amperage?

Fri Nov 19, 2010 3:03 pm

Hmm, well that is interesting. I don't really see how that counts as voiding the warranty. It is the same thing as if I plugged a small inverter into the cigarette lighter, turned the car on, and powered a laptop off it.
I think they are indicating if you tamper with the wiring setup then the warranty is void. There is no way for them to tell if somebody borrowed energy from the 12v battery other than computer logs I guess.

danwat1234
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Re: How is the 12V battery recharged? Max amperage?

Fri Nov 19, 2010 3:20 pm

Though I do admit that one would be in a bit of a pickle if the 12v charging circuitry stopped working (melted/blew-up/smoked/fried). Who knows if that is water cooled or not and has temperature/overload protection.

gregoryjward
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Re: How is the 12V battery recharged? Max amperage?

Sat Mar 10, 2012 9:41 pm

Though I do admit that one would be in a bit of a pickle if the 12v charging circuitry stopped working (melted/blew-up/smoked/fried). Who knows if that is water cooled or not and has temperature/overload protection.

You should be OK with the Leaf fully on and in park. The DC/DC converter will keep the 12v circuit energized at about 13.5 volts once the battery is topped up, and will drive your DC-AC inverter for as long as the 400v main pack holds out. (Probably a good idea to monitor it, but the Leaf will shut off when it's depleted.)

The DC/DC converter is water-cooled with a radiator and fan; it will be fine. Make sure your climate control is "off" or you'll drain your traction battery a lot faster than you'd like and to no purpose.

Hook up your inverter to the battery terminals or the + terminal and the chassis. I have tested this arrangement to about 100 amps (roughly 1100 watts with typical losses) and it works as long as the traction battery is engaged. Without it, you'll drain your 12v battery like no one's business and once that's dead, so will be your Leaf. Even with a jump start, fully draining most lead acid batteries is a BAD IDEA, especially if you leave it discharged for any length of time. I don't think they stock the car with a deep-cycle 12v battery.

The Leaf does automatically charge its 12v battery, but only after 5 days of non-operation. I don't think it will do so more frequently than that, even if the battery gets low. You can try it and see, but as I said, it isn't a good idea to draw down your 12v battery in general.

Overall, the DC-AC converter is a great "emergency plan" for major power outages, but probably not something you should do on a daily basis.

danwat1234
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Re: How is the 12V battery recharged? Max amperage?

Sat Mar 10, 2012 10:01 pm

Heh thanks for the response gregoryjward. Good info

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TonyWilliams
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Re: How is the 12V battery recharged? Max amperage?

Sat Mar 10, 2012 10:13 pm

gregoryjward wrote:The Leaf does automatically charge its 12v battery, but only after 5 days of non-operation. I don't think it will do so more frequently than that, even if the battery gets low. You can try it and see, but as I said, it isn't a good idea to draw down your 12v battery in general.

Overall, the DC-AC converter is a great "emergency plan" for major power outages, but probably not something you should do on a daily basis.


It does a check of the 12v battery at 50 minutes after shutdown. That's why there's notes about removing the 12v for more than 50 minutes.

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