question

mikeg2131 avatar image
mikeg2131 asked

Recommendations to select MPPT controller and settings for a boat

Hello all,

On my sailboat, I have 3 – 130amp -Rolls 12V Flooded Lead Acid Battery (390Amp hr)

I’m planning to purchase 2 x 300 wats 24 volts monocrystalline panels

I’d like to analyze pros and cons for 3 scenarios:

  1. 2 panels and 2 separate controllers
  2. 2 panels parallel and 1 controller
  3. 2 panels in series and 1 controller

Please help me with your recommendations to select controller and settings.

Thank you


Mike G

MPPT Controllers
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

2 Answers
wkirby avatar image
wkirby answered ·

Q1. This is the ideal option if your panels are facing different directions or are subject to shading.
At full power, each 300W panel would be capable of about 22A or 23A battery current after the MPPT controller. You will need a 100/30 MPPT controller for each panel.
A 100/20 would work, but you'd max. it out in full sunshine and loose 30W or 40W. I don't like running equipment at its limits.

Q2. This is the next best option for coping with shading.
You'd get away with a 150/45 MPPT for both panels in parallel.

Q3. Not so good for coping with shading. If a section of one panels gets shaded then the output of both is significantly reduced.
If shading is not a problem then the option offers lower PV cable losses if the runs are long.
The 150/45 MPPT will be fine here too.

Have a play with the online MPPT calculator if you like:
https://www.victronenergy.com/mppt-calculator

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

mikeg2131 avatar image
mikeg2131 answered ·

Thank you very much.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.