Running washing machine without engine on - will I have wrecked my batteries??

[nicknorman]

1 hour ago, Floating Guye said:

So I am actually slightly reassured having read your various comments. I have a MPPT Solar Charge Controller - is this not a "battery monitor"?  As shown on the picture below, it shows me the battery voltage, amps, and various other readings 

Also, I was very reassured by this comment 

 

because (when not in charge) my batteries are almost always in the range between 12.7 and 12.1

Perhaps my batteries are still okay after all?!

The MPPT controller gives battery voltage. It gives current into the batteries from the solar panel, but I very much doubt it gives current out of the batteries into the boat, or current into the batteries from the alternator. The iconography showing battery state of charge is meaningless because it’s only based on voltage and solar current.

 

If your batteries are above 12.1 first thing in the morning then the batteries are adequate for your needs. But probably still quite a lot less than the badged 420Ah. Of course things might change in the winter when there is much less solar and longer darker nights.

[David Mack]

You have 480W of solar panels. So over the summer months they should largely keep your batteries charged as long as you have no excessive battery use (or run the engine while using heavy demand equipment, such as the washing machine). It will be during the winter months that you will need to pay more attention to keeping the batteries charged, as the solar will contribute next to nothing.