Temporary Spare Use and Main Battery Charge

Woke up this morning to a flat LF tire on my 2007 Touring. I threw the temp spare on and drove to Discount TIre to get new shoes. They reasonably priced Bridgestones required ordering, so I drove to work (23 miles or so) with the spare on the LF.

I slowed off my typical highway pace a bit to 60-65, but found the car hunting a bit and jerking with the traction control light flashing. I know the spec that temp spares should be elp to 50 MPH ma, but driving 50 in rush hour traffic is a bit unnerving with most cars buzzing past at 70+.

I've read, however, the threads like this one showing that because the madding traction control that cannot be turned off isn't smart enough to deal with the spare, the car will run poorly on the freeway with the spare on the front. OK, fine, all should be normal once the tires are installed this afternoon.

However, concerned with how it was running, I flipped the info display to show the power flow instead of the bar graphs and found that the battery was down to 2 bars in the purple! By the time I exited the freeway, it was at one bar. But, in the 1-2 miles of slow driving from the freeway to my office, it rose again to one bar short of a full charge. No warning lights on the dash except the flashing traction control (only at freeway speeds) and the tire pressure warning due to the flat.

My 2007 has 178K on it, and the original main battery, so battery issues are an ever present concern. Could my battery woes be related to the temp spare use? It seems like it was, but I've seen nothing else indicating that anyone else has seen this. Perhaps an early sign of battery failure?

 

The tire was probably patchable, but it was nearly to the wear bars so it is time for new tires anyway.

They checked all the tire pressures before I left Discount Tire.

I checked the manual when I got to work and didn't see anything about not using the spare on the front. I didn't read that carefully, though, maybe it does.

 

I plan on driving back to get the tires put on this afternoon either off the highway or slowly on the highway to see if it makes a difference. I expect it will.

 

Back at the tire store. The drive along surface streets was uneventful, no traction control lights, battery level remained in the blue at 1/2 to 2/3 the entire time.

A little disappointed that simply mounting the factory supplied spare to the front of the car can so cripple its performance, but mostly relieved that there seems to be nothing actually wrong with the car.