The C7 is different than prior Vettes! Most power shuts down after 10 minutes! Leave an interior light on and it shuts down by itself! Plug your phone in the console receptivity and <10 minutes later if you leave the car it is shut down (actually in that case much sooner!) The steady state current draw is 30 to 40 millamps, per the Service Manual. I have a higher current draw in my ProStreet Rod and the only electronics it has are the sensor's waiting for me to press the remote for the electric door and window openers, the alarm system and whatever it takes to remember mileage etc in my digital dash and rear mounted stereo components that all have remote operation! But those manufacturers were not designing in the energy efficiency as did GM! I do keep a charger on it's Yellow Optima AGM battery as it mostly just goes to car shows!That draw would be under good weather temps
Hot and cold temps and the draw would be more and discharge quicker
Even if car is sitting 2-4 days using a tender is doing something else
and that is the reverse voltage flow cleans the cells and prolongs battery life
and why my 2 cars which have been on tenders for over 12 years and the batteries for both are still good working order
Also forgotten is people who only do short drives are not getting the battery charge as those who drive longer daily distances
And do not forget all the junk people may be leaving plugged on like a cell phone charger, Bluetooth devices, etc or worse devices like that AFM defeat that keeps waking other modules up adding a lot more current draw
So much so is GM has a TSB as they have caught on to such devices and says if found in car will effect warranty
Agree the battery life may be extended by charging but IMO plugging in a charger for a 2 to 4 day time none use period would be a PIA and not necessary!
I do not use a charger on my C7. It is used 3 to 4 days a week and when I drive it's usually 30 to 40 miles, not 2 miles to a local store (where I live there is no such option!) Have not used a charger in 3 years and been on vacation 3 or 4 times for ~ 2 1/2 weeks and the car starts fine!
I have been checking the battery voltage because it has been low voltage since the car was new. No doubt a weak cell(s) but the battery voltage has not changed and it was still working fine when I decided because of the low voltage to install and AGM before winter. The $133 I paid for the 35% more CCA capacity Sears DieHard than the OEM Delco was cheap insurance, IMO
Your Car Your Choice!