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

[BrockWI]

I finally got to try this out last night. I have a Xantrex Prowatt SW2000. I have the inverter connected with 24" #2 welding cable and big beefy jumper cable clips. I turned the leaf on in park, with the parking break on then connected the positive to the positive on the battery, then connected the negative to the body of the top part of the motor. I turned on the inverter to find it sitting at a nice, 13.2v. I connected up a 1650w electric heater starting first on low at 600w, the voltage dropped a bit to 13.0v and I let it sit for a few minutes checking the connection to make sure nothing got warm. Then I turned it up to 1650w, to my surprise the voltage still only dipped to 12.8v and some of that is likely due to the #2 wire and clips. Again I ran it for about 5 minutes and nothing got warm.

So I think this a great back up to my backup. We have 18kw of flooded lead acid batteries (8 L-16's) with a xantrex 6048 that produces 6000w at 240vac powering most of the load in the home (not electric dryer or evse or geothermal). Typically I charge the batteries via 3kw of solar and the inverter has a sell mode that supports any down stream loads with excess power. I can also charge the batteries via a Honda 2000i and a 120vac to 48 charger, an iota DLS-54-13 and had been using an idling car as backup with the smaller inverter but now I have another "silent" power source.

I doubt I will use it much, but it's nice to know I have it and nice to know if someone else is without power I could just pull up and run an extension cord

[brettcgb]

Where do I need to go to get the right parts to make a safe and reliable connection from the battery to the inverter? .... Or do I need to find an electrician's supply store or a marine supply store?

A marine supply store is a good idea. So is an RV supply store. Automotive audio stores dealing in 1000W amplifiers may also have the needed parts. All carry low voltage (12V), high power, automotive/marine grade electrical components.

Be careful though, I've heard stories where a light fixture "rated" for 8 amps (100W at 12V) used a 5 Amp switch to control the light. That switch has a high failure rate.

[brettcgb]

I would strongly recommend against soldering. The only thing that is going to properly heat a connector and heavy gauge wire up hot enough would be a blow torch. Crimping like KillaWhat did is the way to go!

The recommendation is to crimp, but when this isn't possible, they suggest soldering. There is a real risk of overheating and weakening (annealing?) the contact. There is also a risk of underheating and forming cold solder joints. This takes time and experience.

A heat gun works quite well for heating the contact, though it takes a while. Melt enough solder in the cup to fill it completely. Make sure the contact and solder gets thoroughly warmed. Flux should be smoking slightly. Warm the stripped cable until it also melts solder. Dip the cable into the still molten solder in the contact and hold for a minute while the solder cools and solidifies (wont take long, but you will need gloves and a steady hand). Allow everything to cool to ambient temperature before inserting the contact into the connector body.

If you have experience soldering copper pipe (plumbing), you should be able to solder a cable together. Use eutectic solder and electrical flux rather than plumbing grade materials.

[DaPooch]

Question about the rating on the DC-DC unit:

"The Leaf's DC-DC converter can supply up to about 1.7kW or 135a"

If I wanted to attach a Xantrex prowatt sw2000 (1800W continuous) to this, how would I go about it so as not to damage anything in the Leaf? What would the results of attempting to pull more current from the DC-DC unit than 135A in the event of a surge requirement or just going slightly past to 1.8 Kw continuous? Would the accessory battery be able to make up the difference temporarily? I don't anticipate needing to use a load that large very often but I'm curious if it could be done. I guess the other safe option would be to put a breaker in the mix, but the ones I've seen others suggest break at 150A I thought which is also over the 135A rating. Thoughts?

[LeftieBiker]

I'd definitely go with a much larger accessory battery. Maybe a "marine" hybrid starting/storage battery...

[DaPooch]

I'd definitely go with a much larger accessory battery. Maybe a "marine" hybrid starting/storage battery...

So you're saying replace the existing accessory battery? Has anyone done this? How did you make space for it?

[BrockWI]

I am running the sw 2000 and did load it all the way up with a heater and other restive loads. The small battery in the leaf will help out with surge, but I wouldn't recommend loading it more than 1500w continuous, just to be safe.

[brettcgb]

Question about the rating on the DC-DC unit:

"The Leaf's DC-DC converter can supply up to about 1.7kW or 135a"

If I wanted to attach a Xantrex prowatt sw2000 (1800W continuous) to this, how would I go about it so as not to damage anything in the Leaf? What would the results of attempting to pull more current from the DC-DC unit than 135A in the event of a surge requirement or just going slightly past to 1.8 Kw continuous? Would the accessory battery be able to make up the difference temporarily? I don't anticipate needing to use a load that large very often but I'm curious if it could be done. I guess the other safe option would be to put a breaker in the mix, but the ones I've seen others suggest break at 150A I thought which is also over the 135A rating. Thoughts?

I wouldn't go much above half the converters capacity - the car itself needs power to run. I don't know what the converter can sustain indefinitely, but 1000W should be possible for the short term (30 minutes).

For more power than that, I would consider connecting to the 400VDC battery. Inverters for 400VDC > 120/240VAC exist. But if you need that much power, consider a generator (fewer headaches, longer run time). You don't want to kill the car with modifications or overloads.

[DaPooch]

Question about the rating on the DC-DC unit:

"The Leaf's DC-DC converter can supply up to about 1.7kW or 135a"

If I wanted to attach a Xantrex prowatt sw2000 (1800W continuous) to this, how would I go about it so as not to damage anything in the Leaf? What would the results of attempting to pull more current from the DC-DC unit than 135A in the event of a surge requirement or just going slightly past to 1.8 Kw continuous? Would the accessory battery be able to make up the difference temporarily? I don't anticipate needing to use a load that large very often but I'm curious if it could be done. I guess the other safe option would be to put a breaker in the mix, but the ones I've seen others suggest break at 150A I thought which is also over the 135A rating. Thoughts?

I wouldn't go much above half the converters capacity - the car itself needs power to run. I don't know what the converter can sustain indefinitely, but 1000W should be possible for the short term (30 minutes).

For more power than that, I would consider connecting to the 400VDC battery. Inverters for 400VDC > 120/240VAC exist. But if you need that much power, consider a generator (fewer headaches, longer run time). You don't want to kill the car with modifications or overloads.

I would love to go direct to the main bank but: 1. That inverter I imagine would be quite cost prohibitive. 2. 400v is way more likely to cook me if I screw something up. How would I even go about accessing the main bank leads?

[KillaWhat]

I'd definitely go with a much larger accessory battery. Maybe a "marine" hybrid starting/storage battery...

This is not the route to take.
The "size" of the Accessory 12 volt battery will not help your cause.
Perhaps initially (like the first 2 minutes), then the DC to DC converter will see the load, and begin trying to make up for the loss (charge).

The bottom line is you can only sustain the load the the DC to DC converter can supply.

But now you have introduced a battery with more capacity and consequently requires more power to charge when it gets low, so your requirements are now more variable, and possibly much higher than you intended.

The 1000 Watt continuous pure sine wave is the way to go.
It has something up it's sleeve in a short highload condition, and if you go bigger, your run time drops so much as to be useless.