Recently installed a 12v Multiplus (3000 VA) system with lithium batteries, mppt, DC-DC chargers, etc. into a motorhome.
Core functionality works great. When the inverter is under high current, such as running the AC off the batteries, all of the dimmable LEDs flicker.
To clarify, the flickering is only the dimmable LEDs that are partially dimmed. If the dimmable LEDs are turned up all of the ways, the flickering does not occur. This is happening in three different locations with three different dimmable LED bulb brands (one is a 6ft light strip). Other non-dimmable LEDs show no such problem either.
I measured the voltage for the different lighting circuits and I am getting 13v when there is about a 1.5kw load on the inverter. I tried other high loads such as the microwave and it behaved similarly. Once the load is reduced to 100w or 200w, the flickering seems to go away.
There is a ton of copper wire in the system including 4/0 cables for the 12v supply to the inverter.
Also, I fired up the old 12v lead acid converter and it could power the dimmable LEDs without issue. No flickering off the original AC-DC converter.
Questions:
1) Could this be an interference issue between the power cables? I have the 4/0 DC and 30 amp AC wires fairly close to entering the cargo bay?
2) Could it be a chassis ground issue? My inverter ground goes to the battery bank and chassis. Maybe the chassis ground is not sufficient?
3) Do I need to get ahold of an oscilloscope and do an FFT on the signal? Could ferrite beads help?
Any trouble shooting suggestions would be much appreciated. Thanks!