Dear Doctor: I have a 2006 Mini Cooper S with only 7,300 miles. It is always kept on an OEM battery tender. I had to move the Mini outside in December when a new ceiling was being installed in my garage. The Mini got buried in the snowstorm and the battery went dead. I jumped it and drove for 45 minutes at 60 mph. When I shut it off it was totally dead with no lights, no cranking power. I put it on a 10-amp charge for a few hours and now everything is fine. How long do you have to drive to fully charge a battery? Sherman
Dear Sherman: The battery is original and needs to be checked by a battery shop or automotive shop. You can call 1-800-crankit for and Interstate dealer in your zip code. Also, your original battery is also more than 4 years old and really should be replaced. Regarding how long to recharge the battery, there is no exact answer. You can charge it with the 10-amp charger for 4 hours and then put the battery tender on to fully top off the battery.