Battery isolator

Do battery isolators protect main starting battery from auxiliary drain ?

Check out this website

http://www.littelfuse.com/products/battery-management/battery-isolators/diode-battery-isolators.aspx

It looks like an isolator is for vehicles with 2 batteries.

I only have one battery.

If car goes more than 6 days, I have to top off my battery.

You mentioned “main starting battery”

That’s terminology usually associated with vehicles which have at least 2 batteries

That’s why I directed you to that website

How old is the battery?

What are the current ambient temperatures?

Do you park on the street or in the garage?

Has the battery and charging system been tested?

have you performed a parasitic draw test?

Battery is about 1.5 yrs old. Temps are 60 - 90.

Covered parking. Battery and charging systems ok.

Have not yet done a parasitic draw test.

It looks easy enuf.
I understand that to narrow the drain down, I start pulling fuses one at a time.