Solar Battery Setup Expert Needed

I'm looking for an experienced solar system technician to assist with a G@ HYB-5KW.1.1 QCell system. The batteries in my system are charging slowly and have never fully charged.

Ideal skills and experience:
- Expertise in solar batteries, particularly with G@ and QCell systems
- Experience troubleshooting charging issues
- Ability to check wiring and connections
- Familiarity with system firmware updates

Please provide a detailed plan of action and your relevant experience.