V2L discharge rate anomaly

kosul | 2025-12-25 13:09 | 30 views

EDIT: Ok it's late so I'm going to leave this post here as a lesson in humility, it's kwH not kw so it's just telling me 1.0kw over 6 hours, meaning \~160W/h - \~40W light = \~120W overhead which is amazing! \--Original Message-- Hi folks, I'm going to spend a week at a festival camping and want to take advantage of the V2L capability of my SL7 Performance 2025 (and maybe sleep in the car for some sweet sweet AC if it gets too hot). As a test I have been running V2L with nothing but a 40W LED light plugged in (and the car off) just to see what the baseline consumption of the V2L system uses. So far after nearly 6 hours I have only seen 1% drop (depending on how it rounds), but weirdly the displayed "discharge" rate has crawled up from 0.0kw to 1.0kw over that time with no change in load! https://preview.redd.it/v904hl73nc9g1.jpg?width=2048&format=pjpg&auto=webp&s=a896ef18b604fd031ae191609bbfc2de5e6e02c0 This would seem to be very concerning but if it really were 1kw I would expect to see some evidence of heat waste somewhere and the battery to drop a % roughly every 50mins? Can anyone shed some light on this? Is this some cumulative display calculation bug or a sign of a more serious V2L problem? The math suggests it's not possible to be drawing 1KW but gremlins like this make me nervous!

Comments (6)

Quentinix 2025-12-25 16:43

I noticed the same thing with a citrus juicer. I don't remember how much battery power I used, but I think the car maintains the battery temperature.

Woodwalker34 2025-12-26 01:27

That 120W is pretty good (assuming its a constant load - I would imagine it would fluctuate a bit but averaged over 6hrs is a reasonable average) considering it will still likely be accounting for battery discharge which would include powering the screen and electronics used to monitor the battery and feed info to that screen and any conversion losses. Units of measure catch a lot of people out so dont feel bad, especially when it comes to electricity.

triedtoavoidsignup 2025-12-26 06:57

Where did you find a 40w LED.... That's pretty bright... Are you sure it's not a 40 EQUIVALENT?

kosul 2025-12-26 09:46

No my dude this bad boy is bright! Tri-color (WW,CW,DL) I want my gazebo looking like a warm-white surgery theatre. [https://www.bunnings.com.au/arlec-120cm-40w-diy-dual-power-and-tri-colour-tri-proof-led-batten-light\_p0347567](https://www.bunnings.com.au/arlec-120cm-40w-diy-dual-power-and-tri-colour-tri-proof-led-batten-light_p0347567)

kosul 2025-12-26 09:48

This is a good point the discharge meter may be only partially accounting for overhead.

kosul 2025-12-29 11:56

Quick update for those interested I'm on about 53 hours in. VTOL says 19KW used (~358W Avg). Battery SOC went from 93-70% = 23% drop so 0.825kw/% x 23 is = 18.98kw. It seems the Discharge amount is total battery consumption including internal usage which is odd but ok I guess? Fridge running on non eco setting, lights and fans liberally used, AC overnight but only keeping temp below 24% which wasn't far off ambient night temp. Lots of people charging phones and other negligible usage. 4 more days of camping so I'm feeling confident of driving out of here with enough SOC to get to a fast charger 30 mins drive away! This has been a good exercise and I'm almost ready to swap out my gas cooking setup for a dual inductive top + air fryer if I can find options within the V2L budget :)

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