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Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Fri Aug 30, 2019 7:24 pm
by LeftieBiker
48V will soon be the new standard, as it is used in just about all mild hybrid systems. Not quite enough voltage to be a high level hazard, but enough to propel a car from a stop.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Sat Aug 31, 2019 10:02 am
by Nubo
Seems there was some noise about this a few years back, changing the standard to either 36V or 48V. Haven't seen anything about it in a while though.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Sat Aug 31, 2019 12:23 pm
by LeftieBiker
Nubo wrote:
Sat Aug 31, 2019 10:02 am
Seems there was some noise about this a few years back, changing the standard to either 36V or 48V. Haven't seen anything about it in a while though.
Mild hybrids with 48 volt systems have been quietly multiplying. Everything from upscale pickup trucks to Mercedes cars are using them.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Sat Aug 31, 2019 1:10 pm
by RustyShackleford
What is "mild" hybrid ?

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Sat Aug 31, 2019 2:00 pm
by LeftieBiker
A mild hybrid uses a 48 volt starting motor (often also capable of generating power and acting as the alternator as well) to do two things: instantly restart the engine after it shuts off whenever the vehicle is stopped, and also to add power (especially torque) to the drivetrain when accelerating. The cheapest systems just do auto stop/start, while the more expensive ones add power when driving as well. The full-function systems make the car or truck feel more responsive without the engine having to put out any more power.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Mon Sep 02, 2019 12:41 pm
by RustyShackleford
Trying to duplicate the OP (a little late for Dorian, oh well) ...

He gives pretty detailed info about the parts he uses, but not the 150 amp breaker. Anyone got a good pointer for one of those ? And why not a 125-amp breaker ? That's more than enough juice for the 1000watt inverter he uses, and 150 amps could overload the Leaf's DC-to-DC converter (theoretically the 1000watt inverter couldn't pull that much juice, but if you totally trust your car's welfare to theory, why have a breaker at all ?)

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Mon Sep 02, 2019 12:43 pm
by RustyShackleford
OP has the cryptic comment " I could throw in an LED lighting load by tripping the main for the panel, and back feeding one side, and It wouldn't make THAT big a difference. For giggles, I plugged 2 of them into the cord as well."

I get that he made a suicide cord (120vac cable with male plug at both ends) , plugged one end into the inverter, and another into a wall outlet. Thereby connecting the inverter output to the loads on one "side" of his split-phase main load center. I guess you'd figure out which side your fridge is on, and then hope the couple of other low-load circuits that have useful lighting loads and stuff like your modem, are on the same side; maybe switch some loads around to different breakers if need be. But, WHAT does he mean by the "for giggles ..." sentence ?

And yes, this has the critical requirement that you turn off the main breaker, to avoid backfeeding the grid. Also want to make sure you turn off breakers for any big loads on the side of the panel you're backfeeding. Maybe have a checklist, and strict instructions not to even attempt it unless you know what you're doing.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Mon Sep 02, 2019 1:26 pm
by LeftieBiker
But, WHAT does he mean by the "for giggles ..." sentence ?

It looks to me like he used the inverter to back-feed two house circuits on the main panel.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Mon Sep 02, 2019 5:19 pm
by Nubo
RustyShackleford wrote:
Mon Sep 02, 2019 12:41 pm
Trying to duplicate the OP (a little late for Dorian, oh well) ...

He gives pretty detailed info about the parts he uses, but not the 150 amp breaker. Anyone got a good pointer for one of those ? And why not a 125-amp breaker ? That's more than enough juice for the 1000watt inverter he uses, and 150 amps could overload the Leaf's DC-to-DC converter (theoretically the 1000watt inverter couldn't pull that much juice, but if you totally trust your car's welfare to theory, why have a breaker at all ?)
Iirc, some inverters can support transient loads above their normal rating. Same with the DC power -- for a transient load above the DC-DC capacity, the 12V battery would take up the slack. The breaker is there to protect the wiring and safeguard against short-circuits. The inverter should also have a low-voltage threshold so too high of a load would cause voltage sag and it would turn off. And also, if the voltage does sag a bit but stays within the inverter's limits, the amperage draw for a given load increases.

Amazon seems to carry a variety of high-amp 12V breakers.

Re: Using the Leaf for power in a Blackout: MY "Leaf to Home"

Posted: Mon Sep 02, 2019 5:58 pm
by BrockWI
Just as an FYI this https://www.amazon.com/12V-24V-Inline-C ... r=8-1&th=1 line of "breakers" will trip well below their rated limit. I had a 150 A unit that was tripping under a 75 amp continuous load.

I have given up on "breakers" and gone to inline fuses

https://www.amazon.com/gp/product/B01N2 ... UTF8&psc=1