2021 Yukon Denali - 250w pull is causing 120v outlet to shut-off

[tagexpcom]

My 2021 Yukon Denali has 2 x 120v outlets - that are marked as 400w. However, when I reach 250w-300w range they cut-out. Unplug and replug and they re-activate but again cut-out at 250w-300w range.

Does anyone have detailed power ratings for these or how they work? Is the 400w split between the front socket and rear socket perhaps so that each one is only good for 200w?

And what exactly is this cut-off, re-enable when unplug and plug back in mechanism - is there some kind of circuit breaker reset on the physical act of plugging in?

I have a supplemental battery and my goal is to use the 120v @ 350w range to charge it while driving. Difficult for me to go less than 350w and was hoping this really had a 400w capability.

 

[tagexpcom]

Got a variable 120v -> DC power supply and after some experimentation, the back plug goes dark if it supplies >200w.

Has anyone DIY'ed this inverter / setup or have specs for it? Ideally, I'd like to alter it to maximize watts at 1 plug.

 

[Doubeleive]

My 2021 Yukon Denali has 2 x 120v outlets - that are marked as 400w. However, when I reach 250w-300w range they cut-out. Unplug and replug and they re-activate but again cut-out at 250w-300w range.

Does anyone have detailed power ratings for these or how they work? Is the 400w split between the front socket and rear socket perhaps so that each one is only good for 200w?

And what exactly is this cut-off, re-enable when unplug and plug back in mechanism - is there some kind of circuit breaker reset on the physical act of plugging in?

I have a supplemental battery and my goal is to use the 120v @ 350w range to charge it while driving. Difficult for me to go less than 350w and was hoping this really had a 400w capability.

you would need to replace them with something aftermarket, the specified wattage is "peak" and I am sure it has a duty cycle which means it can only supply that "peak" power for a limited amount of time then it has to have time to cool off, when it shuts down you are overloading it period.
actual usable power from that inverter is probably 1/2 of the rated capacity depending on the duty cycle, like if you plug in something and it has a startup requirement of say 175w, but then runs at 100w that's probably ok, as well needing a little extra jolt from time to time, but if it exceeds the limits it won't work for any length of time

 

[Doubeleive]

if you need more power then it is advisable to buy a inverter that can run at your needed power level full time. Then run a heavy gauge wire from the battery to the inverter and a heavy gauge ground to the frame/body as close as you can to the inverter.

the factory inverter is for small items like a radio or something that doesn't need much juice to run

keep in mind a larger inverter means it will draw more power from the battery potentially leaving you stranded