I've been really frustrated with my EG4 18Kpv inverter because of its terrible web interface, but I think I've finally managed to get it working. However, I still have some lingering issues related to the firmware that I can't seem to explain. Specifically, I'm wondering if anyone has been able to use the RS485 port to read the MPPT startup parameters. It seems like mine ignores PV input until there's stable output of around 100W, which is frustrating since the web interface doesn't provide much information and using Modbus over WiFi feels completely locked out. Before I invest in custom tooling, I'd love to hear from anyone who has experience with this. I'm concerned if this behavior is normal or if I should consider returning the inverter since it's causing me to miss out on solar harvest every morning while it 'wakes up.'
1 Answer
It sounds like you might be facing a configuration issue. From my experience with other inverters, the MPPT output voltage usually needs to be at least 5V higher than the battery voltage to trigger the absorb phase. I had a similar situation, and I managed to fix it by switching from parallel to a series configuration with additional panels to boost the voltage. It worked well in summer but showed the same symptoms during winter.
Yeah, I hear you. I have my system set to a starting voltage of 150V, and even at 200V during the morning, it still takes about 90 minutes for the unit to kick in. It starts at an output of 80W sometimes, which feels way too slow for getting any early harvest. I really agree that it should start drawing power as soon as there's usable input.