Dash Clock reset

2012 2.9L Boxster , 88k miles. I drive it about once a week and most of the time it's on a battery tender when parked. Twice now, i've started the car and noticed that the dash clock has reset to 12:00. First time the car had actually been off the battery tender for a few days. The second time I'd parked it for about 15 minutes to go into the grocery. No other weirdness going on. The car starts and drives as it always has. I don't know the age of the battery. Had the car for about 5 years so the battery is likely due to be replaced. Anything other than a new battery that I need to be thinking about? Thanks.

The battery should have the manufacture date stamped on it. Regardless, I'd have it tested at one of the parts stores (Auto Zone, Advanced, O'Reily, etc). They will do it for free.

Wouldn’t imagine it’s a fault with the battery, since the vehicle starts. The juice needed to crank the engine is far greater than the load of the dash clock, which is minuscule in comparison. Are your radio presets being erased? If not, then the battery is providing power to the necessary components. I would guess the problem lies in the dash clock itself. Couldn’t hurt to have the battery checked, but since the ignition system requires hundreds of amps to start the car and the clock requires probably less than a few watts, doubtful the battery is the issue. Let us know what you find out.

I fully agree with Chuck, however, five years is about all you can expect out of a modern battery. Even less, depending on the climate that the battery resides within. I keep my cells over the plates with distilled water and I can’t say that is adding longevity, but it sure doesn’t hurt. I know that.

The date sticker on the battery is on the side that is not visible, nearest the firewall. i'd have to take the battery out to see the sticker, and at that point may as well just replace it.

New battery has been on my to do list for a bit. Wondering if I should do it now or wait until the spring. I usually park it for a 2-3 months during the winter and leave it on a battery tender . Would putting a new battery in and then putting it on a tender for 2-3 months negatively affect the new battery?

I don’t think putting a new battery on a tender does anything but good for it depending on what brand and design of tender. However if you are not driving it at all waiting till the spring is a perfectly fine alternative, which may add a couple months to its life. As I said, get some distilled water, keep the cells correct, and put a piece of painters tape on the battery so you know each time the date that you filled them .

When my battery condition was not delivering near the rated Cranking Amps I noticed the voltage drop caused by cranking was causing my aftermarket head unit ( Pioneer ) to reboot. The car always started fine but cold booting the radio was annoying since I often liked to listen to the radio while stopped/parked. A fresh battery solved this problem. It is possible this is also happening to the clock. One simple test would be - after letting the car set overnight, insert the key and, before attempting to start, check to see if the clock has reset. Then start the engine and see if that caused a reset.

It’s going to need a new battery anyway so replacing that as a first step toward problem resolution makes perfect sense. That and the well-known issues of ghosts in the machine when batteries start to go bad which has been documented here many times . You can also pull the battery out and take it to say AutoZone and get it load tested.

That’s a good point you made about the voltage drop. Can definitely see a relation there. Pulling all the available voltage when starting could lead to the resetting of the ancillary devices, as you experienced with your head unit. And the test you suggested could provide the answer depending on which way it goes with the clock memory. Good call.

Thanks for the good info. Since I don't know the actual age of the battery (at least 5 years), and cant see the sticker unless I pull the battery out I figure I may as well go ahead and replace it.