120V Inverter Teardown

[Tonicart]

So, if you're running the inverter and you turn on the passenger ventilated seats, it will circulate hot air?

Has any noticed the inverter heating up the cabin during use?

Sponsored

 

[KeeganBuilds]

Resurecting an old thread, but I wonder if something like this would work with some sort of adapter to the the HV lines or even out of the charge port with software update.
https://www.setec-power.com/vehicle-to-home-v2h-6kw-charger/

 

[Dark-Fx]

So the 120V inverter in my R1S developed an internal short and blew the fuse inside the HV pack. My disassembly of the R1T inverter had nothing to do with this occurrence, honest.

Service had to replace the inverter and the fuse. OEM Fuse part number is MEV15, so my assumption is that it's a 15A fuse in the pack.

Which would mean it should be at least capable of 15A output at 240VAC, since the battery voltage will always be higher than that amount. Would be interesting to try and see, but they had to drop the battery pack out to replace the fuse. Not something I'm very interested in doing if it were to blow.

 

[COdogman]

Nothing to do with it, eh? ?

 

[Dark-Fx]

Nothing to do with it, eh? ?

Yeah, I was like, what are the odds I take one completely apart, and have no issues, but the other one I don't do anything weird to stops working. Hmm.

 

[canyonero]

I think i've probably got the same issue, just started a new thread today. how long did they hold onto it for the fix?

 

[Dark-Fx]

I think i've probably got the same issue, just started a new thread today. how long did they hold onto it for the fix?

Took about a week. We had a few other issues on the vehicle, but I'm guessing they didn't expect the inverter and fuse to be bad, because they just got the last parts in on Tuesday.

My mobile tech said it's usually one of three problems. Blown fuse, bad inverter, and could even be an issue with the outlets themselves (it wasn't in my case). I'm guessing the bad inverter sometimes leads to the fuse being blown.

Gen2 could likely be fixed without needing to drop the battery out, for the same problem. So maybe I'll actually look into upgrading the inverter once I get mine..

 

[Zoidz]

...but they had to drop the battery pack out to replace the fuse.

Awesome engineering design, RJ. ?‍

Reminds me of the late '70s Chevy Monza V6 - you had to disconnect the motor mounts and lift the motor a few inches to change right side spark plugs. ?‍ ?‍ ?‍

 

[EVnewb]

Old thread, but I just saw this. Great write up! Really appreciate and respect the DIY curiosity! That’s a serious multimeter too. ??

 

[Dark-Fx]

Awesome engineering design, RJ. ?‍

Likely one of the things that lead to the redesign of the HVDB for gen2.

 

[Big_Booty_Slayer]

I’m actually trying to install some 12v accessories. I’m concerned about the efficiency loss of connecting a 120v lithium charger that would plug into the ac inverter to charge an additional lithium battery to power my accessories. Instead I was wondering if I could maybe just remove the ac inverter and connect an additional dc converter. Possibly even the Rivian dc converter if I could get my hands on one and figure out how to keep it cool. Do you suppose this would be possible? Or would I run into more issues than it’s worth and maybe I should just go with planned 120v charger into the inverter?

 

[Dark-Fx]

I’m actually trying to install some 12v accessories. I’m concerned about the efficiency loss of connecting a 120v lithium charger that would plug into the ac inverter to charge an additional lithium battery to power my accessories. Instead I was wondering if I could maybe just remove the ac inverter and connect an additional dc converter. Possibly even the Rivian dc converter if I could get my hands on one and figure out how to keep it cool. Do you suppose this would be possible? Or would I run into more issues than it’s worth and maybe I should just go with planned 120v charger into the inverter?

Rivian has done a lot of work surrounding not letting the 12V battery die, but you're still going to waste energy either way, since it seems like they have to power up everything to maintain 12V or keep outlets active.

Best course of action definitely seems like having a secondary system with an energy buffer. With Rivian adding in the option of automatically turning on the 120V system when the vehicle is on, seems like a pretty good compromise.

 

[Big_Booty_Slayer]

Rivian has done a lot of work surrounding not letting the 12V battery die, but you're still going to waste energy either way, since it seems like they have to power up everything to maintain 12V or keep outlets active.

Best course of action definitely seems like having a secondary system with an energy buffer. With Rivian adding in the option of automatically turning on the 120V system when the vehicle is on, seems like a pretty good compromise.

Yes absolutely agree, however I was referring to replacing the ac inverter and installing an additional dc converter where the ac inverter is currently located. Then running a power line from the output of that device directly to my accessories battery. Rather than the 10-15% efficiency loss from the Rivian ac inverter, then another 10-15% efficiency loss when I plug an inverter into that outlet to convert it back to DC for the battery to charge. If I were to simply remove the ac inverter and install a dc converter in its place, a Rivian dc converter to be specific, which does not need to be told to turn on as it’s always active as long as power is being sent to it, I’m curious as to whether I would get any fault codes. The only obstacle other than fault codes would be keeping it cool which I could always install cooling fans but the original cooling lines would not be connected. Then I’m wondering if the fan cooling would even be enough, that unit might shut down into a protect mode if it can’t stay cool. The OEM Rivian inverter actually gets cooled by the cars thermal system similar to the way a radiator works. Which is much more effective than simply putting a fan on it. Nor does it have heat synchs to really be able to benefit from a fan. Looks like I’m just gonna have to accept the efficiency loss.

OR

I could put a load on my 12v battery. Let’s say 100amps. And turn the truck on and see how it runs. Because I could always use a victron smart isolator between the dc converter and the 12v system which will always prioritize the factory 12v system staying topped off and when available send additional
Current to the accessories battery. In that case I would just need a larger buffer. Larger battery in other words. But even in that scenario, do I really wanna push the Rivian DC converter to full capacity all the time? Not really. So again, lol this brings me back to the 120v option again.. which still seems like the most practical solution.

Maybe on the next model Rivian will think of the few people who actually want to use the truck for off roading and run winches and other high power equipment and give us an optional 12v power supply for this exact scenario. Because on all my other off road vehicles I was always able to quickly install an upgraded alternator and additional battery and I was good to go hit the dirt. But with this truck i find myself facing some major obstacles when it comes to rigging my truck the way I like to. I just don’t wanna get caught in the mud with my pants down if ya know what I mean. I always like to have my equipment with me for emergency situations. Not only for me, but for my buddies too. It’s not uncommon for us to run a winch. But hey, at least they can use my 8k lbs truck to run a snatch block off my tow hook for their winches lol

 

[Dark-Fx]

If I were to simply remove the ac inverter and install a dc converter in its place, a Rivian dc converter to be specific, which does not need to be told to turn on as it’s always active as long as power is being sent to it, I’m curious as to whether I would get any fault codes.

There's no fault codes that are presented to the user when it doesn't function properly. No idea if Rivian is collecting any in the backend.

The only obstacle other than fault codes would be keeping it cool which I could always install cooling fans but the original cooling lines would not be connected. Then I’m wondering if the fan cooling would even be enough, that unit might shut down into a protect mode if it can’t stay cool. The OEM Rivian inverter actually gets cooled by the cars thermal system similar to the way a radiator works. Which is much more effective than simply putting a fan on it. Nor does it have heat synchs to really be able to benefit from a fan. Looks like I’m just gonna have to accept the efficiency loss.

Are we talking about the same hardware? The 120V AC inverter definitely does not have any sort of cooling lines and has fans.

 

[Big_Booty_Slayer]

There's no fault codes that are presented to the user when it doesn't function properly. No idea if Rivian is collecting any in the backend.



Are we talking about the same hardware? The 120V AC inverter definitely does not have any sort of cooling lines and has fans.

Ok perfect, so when you removed the inverter and sent power to the HV line coming off the battery pack there was no fault code. That’s great news.

and yes I believe you are getting confused as to the hardware I am talking about. It’s probably the way I explained it.

I understand the current AC-DC inverter is air cooled with fans. Because of this there are no thermal lines routed to this part of the vehicle.
The reason I mention thermal lines is because my plans were to get high power dc current to my intended accessories battery. In efforts to do that I was planning on purchasing one of the OEM Rivian DC-DC CONVERTERS. Those converters connect to the HV line coming off the battery pack the same way the DC-AC inverter currently does. They do not require any sort of BMS. There is no CAN communication that plugs into the DC-DC converter unit. It’s literally just HV 400v input and 12v output and a ground wire.

So just to recap, my intentions were to take the current DC-AC inverter which powers the 120v outlets, remove it and install an additional Rivian DC-DC converter which is an identical unit that the 12v system currently uses to step down 400v from the pack to the 12v battery system. The only difference in the two systems is the way they cool and obviously the way the convert power. The Rivian DC-AC inverter is air cooled via two internal fans. However the Rivian DC-DC “400v-12v” is cooled via the Rivian thermal system which is similar to a radiator cooling system. When you look at it you will notice the input and output tubes for the coolant lines.

Being as these two units are both designed to plug into the same battery pack, and run off of the same size internal “battery pack” fuse. And it seems that neither one of them communicate with the vehicle CAN-BUS system. If I could manage to maintain proper cooling on this unit, theoretically I should be able to swap these two units out if I were to purchase the additional DC-DC converter.

Sponsored