Need help trouble shooting an inverter in a micro hydro system

I am looking for a professional to help my son troubleshoot an inverter issue in his micro hydro system. I do not know what type of inverter he is using (he does) but he is experiencing irregular power output and the capacity of my system is less than 5kW. An ideal candidate should have experience with troubleshooting inverters and have a good knowledge of micro hydro systems and their components. If you think you can provide the assistance I'm seeking, please contact me and I will pass the information to my son. If a good candidate comes forward he has done a lot of work with his system and has a good understanding of what is happening. Unfortunately he cannot figure out what is happening with the inverter. The system should be generating more power than it is (145 PSI on a 3" penstock). He has two large lithium batteries that are not being charged properly .....we think it is the inverter causing the issue.