chancecasey

Rats! 2011 S with 55,000 miles, and I JUST put a new battery in a few months ago because the old one was toast. I haven't put a meter on it to see the draw yet, but what in God's name would kill a new battery so fast? Longest I let it sit is 7-10 days in the garage. Zero mods electrically to car that I know of.

Is there a common component failure here i might look for, assuming I find a decent current draw?

This is so annoying. It was happening before and I thought the new battery would fix it.

Dammit!

rusnak

If it's driven once per week, and sits 7-10 days, then you could drain a battery in 3-4 months.

I'd buy a "smart" battery charger with a "float" feature. I have one, but bought one specifically for the Cayman that I leave connected all the time. Charge the battery. The next time you drive the car, before you put it away, check the amperage draw and then charge the battery. After you've measured the amperage draw a few times, average it out and see if it's normal, say less than 30 mA. I'll check mine to compare.

TennisNoob

Are you buying your batteries from walmart?

bernb6

You don't mention how much you drive it in between its resting periods. But assuming it's more than minimal, your standard sized battery shouldn't be crapping out in 7-10 days unless its a rare bad battery. For comparison, I've let my 09 CS sit for 3+ weeks with no problem.

And for the record, here's a reliable (IMO) review site that says Walmart's EverStart battery "finishes just behind the top batteries in expert tests" (http://www.consumersearch.com/car-batteries).

Have you checked at night to see if any light is on? If you can't otherwise confirm, you might disconnect lights in the glove box and frunk to ensure they're not on.

clib

do you lock the car when you leave it sit or leave it unlocked?

rusnak

I checked mine to give you a baseline.

13 milli-amps with the trunk lid closed and the car in sleep mode (doors locked). The car will go into sleep mode with the doors not locked, but it takes around 10 minutes.

'11 Cayman S.

chancecasey

Well I found the problem - a dome light switch was left on. I blame the passenger!