I am NOT a big fan of disconnected a 12VDC START BATTERY from a vehicle when setting for a long time. Who knows how many computers are ON-LINE in the newer vehicles. Disconnecting the START BATTERY may reset your computer settings and the manufactures will say NO HARM as the computers will relearn the settings after you drive again a few times.
I had my IDLE DROP BACK to around 400RPMs on my truck after the battery was disconnected for a couple of days when I was replacing my Alternator.
When I hooked everything back up my truck would die when I stopped at a stop sign. It never did relearn the factory setting. After about a week of having one foot one the gas pedal and the other foot on the brake pedal everytime I stopped I final took it to the FORD DEALER and had them reset the computer setting. Cost was $90 for a ten minute work effort.
I now hook up a low trickle charge if my truck is going to sit unattended for awhile...
Now on my RV TRAILERS I have a BATTERY DISCONNECT SWITCH installed right at the battery terminals and I will disconnect the batteries when setting over the winter months. I will check the battery voltage a couple of times over the winter months. Have no problems with them draining down when totally disconnected.
Roy Ken
My Posts are IMHO based on my experiences - Words in CAPS does not mean I am shouting
Roy - Carolyn
RETIRED DOAF/DON/DOD/CONTR RADIO TECH (42yrs)
K9PHT (Since 1957) 146.52M
2010 F150, 5.4,3:73 Gears,SCab
2008 Starcraft 14RT EU2000i GEN
2005 Flagstaff 8528RESS