Join Date: Feb 2007
Location: Spain + Germany
My Motorhome: Four Winds RV
Thanked 668 Times in 619 Posts
Efoy and solar panel will almost certainly operate together, which will mean at times that the Efoy is being used to do work that the solar panel would have done given time. Solar energy is free-ish, power form your Efoy is very far from free. Why leave it on auto if you don't need to replace the charge right at that time. Let's say it is evening but the sun will come up in the morning, or it's evening but you will be driving the next day?
In my view the automatic setting is there mainly for use when charging unmanned applications or vacant vans, but of course Efoy won't mind if you leave it on auto, all the more dosh for them when the unit needs a premature refurb.
Remember that your Efoy is only expected to give around 3000 hours use, that's 125 days. You could, using it carelessly, use that in one year.
Your decision , Alan.