It’s always great to have a spare vehicle on hand.
You can usually leave a car sitting for about two weeks without starting it.
This limit varies, but the battery will lose a significant amount of charge and you may find yourself needing to jump-start your dead car battery back to life when you do need your spare.
To extend your limit a little more, you can disconnect the battery.
But it’s not only about battery life: leaving a vehicle sitting for too long can also cause corrosion of brake pads and tires.
Pro tip: The best way to prevent unnecessary wear on your vehicle is to take it for the occasional drive, ideally every couple weeks at slower speeds and at faster highway speeds. This will keep essential fluids circulating properly and allow the alternator to recharge the battery.
All in all, it should help you keep your spare vehicle in good working condition for as long as possible.
As for your spare vehicle’s spare battery: a new, unused car battery can often sit unused for two to four years and still work—as long as it’s properly stored and maintained. For maximum shelf life, be sure to:
Store the battery upright.
Keep it in a dry, well-ventilated area.
Avoid temperature extremes and try to keep the room around 60°F.
Connect the battery to a smart trickle charger or charge the battery every two weeks using a standard charger.