Hi, I am a beginner, so please bear with me. I recently installed a solar system that's tied to the grid. It has a 200ah, 24v lithium battery, an 3kva Must inverter (probably the thing behind the problem), 4 *370w solar panels connected 2s2p. The issue is that whenever the sun gets up in the morning, the inverter throws either a "battery is overcharged," or "voltage is too high," error. I have tried everything in a bid to resolve the issue to no avail.

Part of the challenge appears to be that my lithium battery is unbranded and I am yet to establish communication between its BMS and the inverter. That experiment is ongoing. I don't get the error when connected solely either to the grid or to solar. But that's not how I wish to have the system work. I want to save on utility energy costs, while not straining my battery and inverter. 

One possible solution that I have thought of is to install an electronic timer to switch off the utility at a particular time in the morning. Then utility power can be switched on at another set time in the evening. That way, there won't be the conflict between the grid and solar which appears to be causing the battery overcharged issue. Note that when I get the error, it's not the case that the battery is actually overcharged. The voltage at the battery will usually be lower than the set range.  

I thought it was a momentary spike in voltage caused by the freezer kicking in, but the error has also occurred with the freezer switched off. Anyway, I just wanted to find out whether the timer solution has any possibility of working. 

Welcome!