question

It's difficult to answer because it's not certain what's happening or how the LED driver is constructed.
I doubt it's any type of interference in the cables that any sort of filtering could fix.
It seems to me that reactive loads are causing distortion of the AC sinewave that the LED driver is particularly sensitive to. This sort of distortion is inevitable with a reactive load on a microgenerator which has a relatively small output transformer compared to a substation or pole transformer.
A lot of the time these LED drivers are built to a price and will work only in absolutely perfect conditions. The drivers themselves are probably chopping the sinewave for dimming and introducing even more distortion.

I'd be interested to find out what brand or model of LED strips you are using and get some myself. Then analyse them and figure out what's going on exactly and perhaps find a way to solve the problem.

The LEDs are 12v and are dimmable T4s and a dimmable light strip from Boogie Lights. No Boogie Light controller, just an inline dimmer.

If I am connected to shore power and the inverter is in passthrough mode, I don't have the flickering issue. The main load is 120v in and 120v out. It only seems to occur when I am pulling hard on the 12v battery bank with a large inverter load (~50 amps and above).

I am planning to double check my chassis ground. Anything else I should take a look at?

Thanks!

Some dimmers are very sensitive to the DC voltage and even a few tenths of a volt can make a huge difference. I tested several dimmers and ended up with the type that has a separate positive and negative source and separate positive and negative load connections. The "in-line" types were much more apt to flicker especially at low brightness settings, sometimes even without any DC loads on the system.

Make sure your inverter is connected to the battery (or the shunt) without using the chassis connection to avoid any chassis-related voltage drops. In fact minimizing any chassis current with negative "return" wires for all circuits is a wise goal.

Try bypassing the dimmer and powering LED directly - does it flicker? Then you know if the dimmer is really the culprit.

Yeah, I have 4/0 wire for both positive and negative between the inverter and the batteries. I also have a chassis ground off the main bus bars.

Can you please provide an example of the dimmer that you found to work under 12 loads? It sounds like you have experienced the same issue as I am working through now. I believe my current dimmer would be considered an "in-line" type.

If I turn the dimmer to the brightest setting, all of the dimmable LEDs work fine even under load. The issue goes away. If the batteries are under load AND the LEDs are partially dimmed, then the flickering shows up.

Thanks.

I am using these:

https://amazon.com/gp/product/B01C4UBMY6

When I wired these in-line the lights would flicker at certain brightness but when wired in a 3-wire configuration with a separate negative wire for the supply, they are much more stable

https://www.amazon.com/gp/product/B072349JZN

This has separate line and load wires for both positive and negative.

I should note that the LEDs still flicker a bit. I have multiple lights on one dimmer and some of the lights flicker while others on the same dimmer do not.

The flickering I experienced had nothing to do with my Multi Compact so this may or may not help.

Do you think this DC-DC stabilizer might work?

When troubleshooting I start with the basics. You mentioned ground path - I would learn about single point ground systems, aka. star grounds, ground window, etc. (https://hennulat.wordpress.com/2012/04/28/grounding-and-bonding-best-practice-wired-star-grounding/ is one piece to start. If the battery return path is shared, then ”ground” is no longe at zero potential

This may or may not be not the problem, but rule out the easy stuff first

Good luck!

Thanks for the tips regarding the ground path.

I tried the DC stabilizer and it did seem to cure the issue. The dimmed LED does not flicker while the inverter is under higher loads. So far I have tested it on the light strip.

Can you share which stabilizer you used?

Phillips makes a flicker-free led light bulb that solves this issue for regular kitchen floods

https://www.amazon.com/dp/B07C3YLLTM?psc=1&ref=ppx_yo2ov_dt_b_product_details