Long-Term Parking Doesn't Have to Drain Your Power

Dear Car Talk

Dear Car Talk | Jun 25, 2019

Dear Car Talk:

This September, I will be parking a 2016 RAM pickup truck in long-term parking at an airport for 3-5 weeks.

Should I disconnect battery? Is that OK to do? What is the maximum amount of time I can safely leave the truck parked with the battery connected? Thank you. -- Hank

You can safely leave the truck parked with the battery connected until the 115th season of "Game of Thrones" debuts, Hank. It'll never be unsafe. The truck just won't start after three or four weeks.

Every modern car uses some amount of battery power even when the vehicle is parked and shut off. There's the alarm system, stored electronic settings and the evaporative emissions system. Those all draw power.

If you want to park the truck longer than a few weeks and start it when you come back, then you have two choices.

Option one is to hook up a trickle charger (also called a battery tender). That device plugs into a wall socket and "trickles" a small amount of current to your battery, to keep it always topped up.

If you don't have access to an outlet -- say, in a long-term airport parking lot -- then your second option is to disconnect the battery. That'll preserve the battery's charge, so when you reconnect it, the truck should start right up.

The downsides are minimal. You'll have grease on your hands when you go through your TSA screening. And you'll have to reset things like your radio presets and seat memory buttons. But the transmission computer parameters and stuff like that will reset themselves on your drive home. You likely won't even notice anything.

So, bring the right-sized wrench with you, disconnect the negative terminal, move it away from the battery and then straighten out that battery cable. Maybe even put a little crimp in it so it's "metal muscle memory" doesn't drag the negative terminal back to the battery while you're away.

Reconnect it when you get back, and you should be all set, Hank.

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