2000w Inverter Install

Seems like not so long ago, settling a different question, I ended up measuring resistance of mated Anderson PowerPoles. Those were the smaller ones, the family that tops out at 45 amps. The bigger ones would have lower resistance than that.



If you were actually pulling 2 kW, the input at 13.8 volts would be around 150 amps, and (150A)² ✕0.00032 Ω would be about 7 watts dissipated. Double that to 14 or 15 watts since it won't just be a connector on one side of the input. So that's a little bit less than 1% of the power.

Again, even that is unrealistically high, because you wouldn't be using the 45 amp flavor of powerpole to handle 150 amps.

 

I am new to Prius and Prius Chat. I have just bought a 2021 XLE Prius Prime and I would like to do what the original post did, namely use my Prius as a 120 volt ac power source. For me it would be every few years to power a refrigerator in a wind storm power outage. My plan is to put the Prius in Ready, then attach a 2000 watt pure sine wave inverter to the 12 volt battery and then plug the fridge into the inverter. So the high voltage traction battery will power a DC to DC converter to step down to 12+ volts.
My question is: what is the limit of this use of the car to avoid any damage to the car? Correct me if wrong, but wouldn't the limit be the power output of the converter? Is heat a problem with the converter? Will the converter protect itself if it is overloaded?
Could I use the Torque App to monitor sensors to keep my 120 volt AC power draw safe for the car?
All help much appreciated.

 

The converter has an output power rating. For the 2010 (Gen 3) that I have, the rating can be found in the New Car Features Manual (more info) and is 120 amps. I have not looked up the corresponding figure for Gen 4 or Prime to see if it is any different.

The Gen 3 converter output voltage varies between about 13.6 and 14.8 depending on some conditions including temperature and the condition of the aux battery. PriusChat member RGeB has scoped some of the interesting voltage tricks the converter may use to determine the battery condition while driving.

So, conservatively, use the lower expectation for voltage and the 120 amps to figure the converter can supply around 1600 watts maximum. Naturally, the car itself needs some of that, around 400 watts minimum, more depending on what features are in use. The generations I'm familiar with have supplemental electric heat elements active in chilly weather and worth about 700 watts just on their own.

The converter has a few means of protecting itself from overload. Again, in the generations I'm familiar with (1, 2, and 3), it has a signal "IDH" that it can use when near overload, and the car's A/C controller will respond to that signal by shedding the electric supplemental heat, if that is in use. Nothing else built into the car uses the IDH signal, but I have often suggested that anyone installing a large inverter might also be well advised to tap that signal and monitor it, maybe even build an automated circuit to shed inverter load in response.

In earlier generations, IDH might have been a simple signal you could monitor the level of. The repair manual for Gen 3 suggests it may now carry messages in the form of a pulse train; there aren't any more details of the protocol given than that.

Years ago, with a Gen 1, Bob Wilson did some tests near a kilowatt of load and found that the converter's output voltage began to droop, which isn't terribly surprising.

The converter's temperature is monitored and it can be shut down if overheated; this is regularly demonstrated here when members have their inverter coolant pumps fail. It can be restarted after cooling down. It doesn't seem to take obvious damage from a few such incidents, but we don't necessarily know the effects of longer-term repetition.

 

ChapmanF, thank you for your kind post answering my questions. I learned more from your message than I did from hours of searching past threads and posts. You also gave me direction on how to move forward, especially if I want to draw more than 1000 watts out of the low voltage system of the Prius. I will look for the New Car Features manual for my 2021 Prius Prime and I will look for the Converter high load signal and the coolant temperature sensors in the Torque App.

 

So I connected a 2000 watt pure sine wave inverter to the Prius 12 volt battery and put the Pruis in READY condition and connected the refrigerator as a test of how it would work in a power failure. I ran the fridge for about 8 hours and used up about a third of the traction battery charge. I recorded a maximum draw of 464 watts, although most of the time the draw was just over 100 watts. The total power consumed by the fridge over 8 hours was 0.887 kwattHrs.

The only problem was keeping my 2021 Prius Prime XLE in the Ready state. It wanted to automatically shut down after about an hour. After it happened the first time I left the key FOB inside the car but it still shut down. I tried locking the doors with the mechanical key, with the key FOB outside the car and it did not shut down after that.

Since I only used a third of the drive battery, I did not confirm that the engine would eventually start automatically to charge the Hybrid battery and cycle on and off as needed; but I plan to try it in the future.

Except when the car dropped out of READY, the 12 volt battery stayed between 13.9 and 14.2 volts. The first time the car dropped out of READY, the 12 volt battery dropped to 12.4 volts before I noticed the problem. The second time it was 12.6 volts. It shouldn't happen again because now I know how to keep it in Ready (lock the doors).

The Power Factor of the fridge load was .62 to .65 most of the time except once when the power needed went up and the power factor was 1.00

I hope this helps others.

 

Your observation applies to this new feature found in 2021 and presumably 2022 PPs. 2020 and prior models of PP did not have this automatic shut-off feature. Yes, locking the door is needed to disable the shut-off feature.

 

Yes! Exciting stuff. I want to do this too. I got so far as having a manual one-circuit transfer switch installed professionally just for my furnace. Unfortunately, when I connect my inverter to that, there is some ground issue and it doesn't work, but I can run a 700 watt AC power tool, so there is hope, and I will try my fridge one of these days!

You probably already said you did this, but just in case... Please make sure you have your inverter set with a fuse (or you can buy a DC breaker switch in different amp ratings, like I did). You don't necessarily want to rely on your inverter's fuse for safety or for cutting out before the car's internal inverter fuse blows. Make your fuse lower than the car's internal fuse rating. I forget what that was (it equalled about 1000w I thought in my Gen 2), but you may already know it and others will tell you for your model/year.

This is probably very obvious, but make your 12v copper red/black cables between the car and the inverter as short and as fat as possible, less resistance/loss/heat/trouble...

 

I would have thought that the ground prong would ground the furnace to the transfer switch to the inverter to the car. I hope you solve it to get it working to run your furnace.

Thanks for the fuse advice Wagner, I'll have to give that improvement some thought. In my case I put a manual transfer switch near my electrical distribution panel which is also right in front of the parked Prius. I used a heavy duty jumper cable (#2 wire) with alligator clips for the battery connection and a tab fitting to bolt to the inverter. The run is 4 feet. The inverter output goes another 4 feet to the transfer switch through a short #12 extension cord. During my 8 hour test nothing got warm although the inverter fans cycled on and off. It was about 82 degrees in the garage. The transfer switch has a 15 amp breaker and the inverter has over temp and over current protection; but that is it. So you think I should get a DC breaker for the inverter input? How does 100 amp sound? Could you describe how you mechanically connect it. I don't really want to touch the car/battery side so can you get breakers that bolt onto the inverter and then the battery wire bolts to the breaker? Is that what you did? Thanks.

 

I think it would be ideal if someone with an amp meter and an inverter would do what we can watch in the video below. The professor determines the amp draw from the dc converter to the 12v battery under different conditions. What we need is tests under inverter loads.

Anyone have the equipment to do that? It only takes one meter not the three in the video (placed in the location where the professor places the last meter). I’d like to know this to inform my inverter choice.

And do we know the amp size of the built in fuse between the dc converter and the 12v battery for the recent Prius Primes? At five minutes into the video the professor says it is 120 amps but he is using a Prius and not a Prime.

@bwilson4web @jerrymildred @Mikhail Bond @douglasjre @2021PPxle @C Wagner

And @ChapmanF would you be able to show us in a photo the location you are recommending in comment #110?

 

Helle, I own a 2012 Prius plug in, I want to add a 2000 watt inverter to connect it to the hybrid battery, so I can run power to my small camper. The most power I plan to draw is 1500 watts continuously. I looked at a video how-to, there seems to be only one video on youtube connecting the inverter to the traction battery

. First, would the system I plan to instal work as expected? Second, could you suggest a well-made inverter at a reasonable price? Perhaps any other advice, that is simple to understand.

 

Hmmm, looking more into it. I gather that the above video is lacking info. I sense reading some of his comments he bought a specially made high voltage dc to ac inverter made particularly for a house. It would be too worrisome to run to power leads from his Prius traction battery 230 dc volts even having an Anderson power connector on the end. Even so was interesting.

 

I don't own a Gen 4 or Prime, so I've got no easy way to go snap a photo. But I think "car side, not battery side, of battery state sensor assembly" ought to be unambiguous enough, with a little bit of looking.

Especially as that sensor is installed on the negative side, so legitimate "car side" connections would be pretty much anywhere on the metal structure of the car. The only thing to avoid is connecting your negative return at the battery itself.

It sounds like you are looking for our thread on that topic.

Electric power from a hybrid, connecting inverter to the high-voltage system | PriusChat

 

4.5 hours since I started the generator. The Prius is parked in a garage at Dulles airport, about 175 miles away.

Just throwing another one on the scoreboard- I'm home with the baby today, and we've had power and heat because the generator worked even though the Prius was out of town today.

 

I ran a 2000w harbor freight inverter on my 2012 plug in Prius for several years. I used shorty two foot long, thick gauge cables also from harbor freight. There were no fuses, and it was a very easy and clean installation there in the trunk. I would use it during power outages. It powered the furnace (electric fan w gas heat), several lights, tv, Wi-Fi, and even my wife’s hair dryer. I loved it. The fan peaked at 1600w just when turning on and settled at 600w. Then last November the Prius Plug In was totaled:-(. I took the inverter out and am gonna install it in my Prime. I’m gonna have to get a longer red cable from battery to inverter, and ground off the chassis. I reckon I might even add a fuse. Thanks everyone for all of the insight in this thread ! Prius Prime / Plug In 12v inverter is the way to go.

 

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Another post made on generator power.

But this time, the Prius is home. If I had an inverter system I would not need the racket and fumes. Just keeping the score honest.

 

You don't need that heavy cable if you use PlugOut Power inverter that runs off the traction battery.

 

With the dropping prices of LiFePO4 batteries, my current recommendation is to install one or more ($400 to $500) 300Ah batteries in your home, and keep them charged from home power until power is out. Then if needed, you can charge them with a 40A-60A lithium battery charger powered by 120VAC, plugged into a pure sine wave inverter hooked to the Prius battery.

For car camping, I'll be upgrading my setup from this:
100Ah LiFePO4 battery charged by 8A charger plugged into 12V power socket

to this:
160Ah (30 pounds) or 300Ah (56 pounds) LiFePO4 battery
charged at 30A by Kisei DMT-1230 DC-DC charger hard wired to car battery (and fused there)

You can fit the new smaller form factor 300Ah battery in the front passenger leg area and still have room for a passenger's legs pretty much unhindered, though I do my car camping trips solo.

I own the Kisei DMT-1230 already, having grabbed it on a crazy Amazon price fluctuation down to $130.

The DMT-1250 is nicer in that you can choose any charge rate in 5A increments from 5A to 50A,
while the DMT-1230 gives you choices of 5, 10, 20, or 30 amps. Both also have an MPPT solar charge controller so that you can also hook up solar panels to charge your LiFePO4 battery, and it auto-switches to charging from the car when the car is turned on (if you attach a wire which goes to 12V when the car is on).

At home, another way to go is with a rack-mount 48V battery system, and an "all in one" charger/inverter with AC input and solar input, plus of course AC output. Will Prowse shows many such systems on his YouTube channel, and he often mounts them on either a hand truck for portability, or on a wall if he is keeping it in one place.

 

@OptimalPrime Do you have a plan in place for ,monitoring the 12 volt system in the Prime while using the inverter connected to the car? If switching to HV mode works at keeping the 12 volt system healthy while in camping mode a separate 12 volt system monitor might not even be needed. Might be worth a look at how it works before diving in with the inverter install in the Prime.