Inverter to power refrigerator during power outage

[Kenric]

After a bad storm, we lost power and it wasn't predicted to come back on for 24 hours. I thought this would be a good opportunity to use my 2013 Leaf as a giant battery pack. I bought a 750W inverter, which should have been big enough to power my 5.1A fridge, but it wasn't able to power it. It did come on, the lights worked, the temperature readings worked, and if i turned off the cooling the fans would run. But not the compressor. I returned the 750W and bought the largest they had which was 1000W (2000W for 0.1 seconds) and it still wasn't able to run the refrigerator. Both were able to power a small 1A refrigerator. Luckily, the power came back on after 18ish hours, but I hope to learn what the correct solution is for next time. Any ideas? The 750W inverter never reported over current. The 1000W doesn't have any way to report that. I assume there is a large inrush when starting the motor, but not sure how I can easily measure it to know what size inverter I would need. I also thought about it later and the fridge must be sensing and not trying to turn on the compressor for some reason, since the rest of it worked fine.

[LeftieBiker]

Larger electric motors have a high startup power requirement. I would have thought a 1500 watt inverter would handle it, but if it's a large fridge, look for a good quality 2kw inverter with a 3kw surge capability. Remember, though, that the Leaf's DC-DC converter can only provide 1800 watts, and 1500 is safer for long periods. The car *must be* in Ready mode, with the yellow-green car icon lit, and remain in that mode. There is a topic on this. try searching 'Leaf to home'.

[Nubo]

Were you using a pure sine-wave inverter? Some appliances and/or motors do not like square waveforms. Especially newer stuff which is more likely to have fancy electronics and variable-speed motors. I'd bite the bullet and get a good pure sine-wave inverter. Especially if you ever intend to use it to power expensive electronics like computers, etc... And while some things may *work* with square waveforms, it can put unwanted stress on the components.

As for inrush current, the manufacturer's info plate on the unit may tell you what the starting draw is. I think you didn't exceed your inverter's capacity if it didn't trip. Furthermore, 2000W is in excess of 15A and unless you've got some huge commerical refrigerator I doubt it's pulling THAT much current. There's usually a capacitor that provides the starting kick.

One other thing to check was whether you had a proper ground.

[RegGuheert]

I bought a 750W inverter, which should have been big enough to power my 5.1A fridge, but it wasn't able to power it. It did come on, the lights worked, the temperature readings worked, and if i turned off the cooling the fans would run. But not the compressor. I returned the 750W and bought the largest they had which was 1000W (2000W for 0.1 seconds) and it still wasn't able to run the refrigerator.

Here are a few questions:

Q1) Was the LEAF in "READY" mode? This is the mode that you use for driving with the green car and bidirectional arrow showing on the dash. You need to use that mode to get the 12V battery to charge.
Q2) What is a "5.1A fridge"? My fridge consumes about 100W when running and draws about 1000W to start the compressor.
Q3) How old is your fridge?

And here are a couple of comments:

C1) I find that I need to use a 1000-W inverter to start my large side-by-side fridge. Smaller sizes do not work.
C2) I used the same modified sine wave 1000-W inverter to start my neighbors fridge and it had a lot of trouble getting it going. That refrigerator was old and drew quite a bit more current to start. I *did* eventually get it to work, but I don't recall what the trick was.
C3) If I need to run multiple refrigerators during an outage, I typically connect multiple inverters to the battery.
C4) Note that a normal 15A plug is limited to about 1800 W, but the circuit breaker will allow a starting current much higher than that for a few seconds.

[Kenric]

Thanks for the replies. I know about the car needing to remain on in ready mode. I did have it that way. I measured the voltage and saw 14.4V but I think it went as low as 12.6 to 12.9V when the inverter was pulling power. It says "modified sine wave converter', but I don't know exactly what that means. Ground is something I didn't really think about. I am sure it wasn't properly grounded. There is an earth ground lug on the inverter but I didn't connect it to anything. I guess I should have connected that to the house ground somehow. The fridge is just a normal full size Samsung. The label doesn't have a startup max power, just lists 5.1 Amps which I assume is nominal max power. It is maybe 8 or 9 years old side by side.

So best guess by Nubo's comment is that it was the ground.

I guess it could have been voltage drop over the 25 feet of extension cord too, I didn't think about that either. I should have measured the voltage when plugging in the refrigerator.

Maybe I will give it another try this weekend to see if I can get it to work just in case I need to do it again in the future.

[Nubo]

Thanks for the replies. I know about the car needing to remain on in ready mode. I did have it that way. I measured the voltage and saw 14.4V but I think it went as low as 12.6 to 12.9V when the inverter was pulling power. It says "modified sine wave converter', but I don't know exactly what that means...

https://www.altestore.com/blog/2015/10/ ... ifference/

[Kenric]

Thanks for the replies. I know about the car needing to remain on in ready mode. I did have it that way. I measured the voltage and saw 14.4V but I think it went as low as 12.6 to 12.9V when the inverter was pulling power. It says "modified sine wave converter', but I don't know exactly what that means...

https://www.altestore.com/blog/2015/10/ ... ifference/

yeah, I was just reading about MSW vs PSW. So you think I would need a PSW inverter to run it?

Also read that the earth ground is connected to system ground for most of these, but I didn't check mine yet.

[smkettner]

Starting a full size home fridge needs a lot of good power. Yes you should have a sine wave inverter. Probably need 2000 watts rated and 3000+ watts surge performance. If the 12v wires are short you can probably get by with 2/0 wire (the size of a small garden hose). Next you need a larger 12v battery to even utilize the surge performance. Yes it is a bit of an ordeal to be prepared for an outage without running the generator.

Start current can be 5 to 10 times the rated current for these appliances. Once the compressor is running all becomes simple and the LEAF can supply the power.

[BrockWI]

I use a 2000w xantrex sine wave inverter and it will start anything you can plug in to a regular wall outlet.

What size cables did you have between the Leaf's 12v battery and the inverter? I ask becasue you need at least #4, I use #2/0 and it is only about 2 feet on each lead. Even #4 will sag voltage to the input side of the inverter quite a bit on motor startup, enough to put most 1000w inters in to low voltage shut down or fault. The more larger inverters won't mind the voltage sag as much, but smaller ones really need heavier wire to avoid voltage sag.

Also larger inverters tend to not care what the input voltage with regards to the output voltage, but less expensive inverters tend to just 10x the voltage. So say your input sags to 11vdc the output will be 110vac, where larger inverters will draw more power on the input side keeping the output voltage at close to 115 vac or so. As the output voltage dips it is less likely to start a motor.

[jdcbomb]

With Hurricane Florence hitting NC these last few days, I ordered a 1000 W pure sine wave inverter (peak 2,000 W) From Amazon. $150 (some no-name Bear Claw brand). Came with short battery to inverter eyelet cables. Although I did not lose power, I decided to test it out on various appliances (including full size fridge) and overall it worked great running from my 2013 LEAF inside my home garage.

Hooking it up was easy, just needed a small wrench to loosen the bolts on the battery terminals and insert the eyelets which I then hand tightened. Not sure if I followed the right sequence in connecting, but it worked fine.

With the inverter connected (LEAF off), I turned it on and it immediately showed voltage of 12.8 V from the battery and output of 115 V. I then put the LEAF into ready mode. The following are items I tested, not all at the same time:

Chest Freezer (5 cu ft, 180 W est)
Floor Fan (nothing special)
Floor Lamp
Full Size Fridge (24 cu ft, 650 W est, Peak 1800 W est)
51 in Plasma TV (110 W)
Hair Blow Dryer (800 W est)

I ran the freezer 10 hrs overnight and the SOC showed 85 pct the next morning. The use included running a floor fan + TV at the same time for 2 to 3 hrs.

Then I just ran the full fridge by itself with a 50 ft extension cord. It took about 8 min for it turn on, while the inverter fan kicked on for a few min. In the end the compressor did work, and fridge did run for over an hour. That reduced the SOC by only 2 pct. I bet I could concurrently run BOTH fridges at same time but didn't see the need.

Based on this usage, I could easily intermittently power both freezer and fridge, various small appliances, TVs, Laptops, for minimum 4 days without issue. I would have one cord dedicated to the fridge while using a surge protector to split up power to everything else on the 2nd output outlet.

Impressed at the silence, lack of fumes, no hassle backup generator I have with my LEAF, and plan to use this setup for any future disasters or just for fun!

Would be nice if Nissan or someone could make available in the USA a kit to just plug in the CHADEMO or L2 port and output power directly into the main house grid (via transfer interlock switch of course. But this mode using an inverter is good enough for me for now.