Hi solar experts. I have been on this site silently many times and learnt a great deal. Helped me properly spec my solar system. However I have a small issue. At the moment I have 6x330w solar panels, a Luxpower SNA5000 and a Greenrich UP6100 battery. The panels are connected as one string into PV1 MPPT. However since winter started, solar power production can only charge the battery up to 75-78% SOC, maybe 80-85 SOC on a really good day. So I've been thinking about adding more solar panels, but this time I want 465w of 550w solar panels. Is it possible to add panels of a completely different specification to the ones I currently have? Would the inverter accept input from two strings made up of different specification solar panels? Am I asking for trouble? Thanks for your assistance.

4 hours ago, LeProfesseur said:

Hi solar experts. I have been on this site silently many times and learnt a great deal. Helped me properly spec my solar system. However I have a small issue. At the moment I have 6x330w solar panels, a Luxpower SNA5000 and a Greenrich UP6100 battery. The panels are connected as one string into PV1 MPPT. However since winter started, solar power production can only charge the battery up to 75-78% SOC, maybe 80-85 SOC on a really good day. So I've been thinking about adding more solar panels, but this time I want 465w of 550w solar panels. Is it possible to add panels of a completely different specification to the ones I currently have? Would the inverter accept input from two strings made up of different specification solar panels? Am I asking for trouble? Thanks for your assistance.

Winter production is always less than summer. Yes you can add different panels onto MPPT2 or add more ont MPPT1 - up to another 6 

Edit: just don't mix different wattages on the same MPPT

Edited June 11, 20233 yr by mzezman

7 hours ago, LeProfesseur said:

Is it possible to add panels of a completely different specification to the ones I currently have? Would the inverter accept input from two strings made up of different specification solar panels? Am I asking for trouble?

Seperate MPPTs don't have an effect on one another.

First prise on a MPPT is to maximize the voltage and to not have parallel strings. If you have to add panels of a different specification to one string, try to add ones with the same or slightly higher current at maximum power output. All panels on this string must be in the same orientation. If you have to add a parallel string, the voltages at maximum power should match and the sum of the currents must be within the MPPT rating. You could have strings in different orientations but you won't get maximum energy out of your panels. You can consider power optimisers if there are only a couple of odd panels being added to a string.