williet

I had a similar issue many years ago, turned out to be on the db where the one breaker was not torqued in correctly, that slight "looseness" caused havoc.

That is vague terrible advice. Why once a week? Why 50%? 
 
Guys you have to actually read before commenting. It's a lithium battery you can cycle it everyday down to 80%(I mean you can use 80% with 20% remaining)and still get minimum 6000 cycles.
 
Cycling it everyday will give an idea of how far you are from self sufficient,  you could be 2 batteries from self sufficient depending on your load in the evening. 

@williet, if I were you I would direct the question to the manufacturer, who is responsible for the batteries' warranty.

General rule for lithium batteries is cycling is good for your pocket and for the batteries.

Once a week to 50% should do very nicely.