Low battery charge warning question

[330iTiAg]

I have a low mileage 2011 E92 M3 that I bought new. It has less than 16K miles on the clock. Just recently, I've been getting low battery charge warnings about 30 seconds after shutting off the engine (while still listening to the radio). About another 15 seconds later and everything powers down automatically.

It’s been really cold lately, so I took my car in to have the battery checked. The dealership (which I trust) tells me that they looked at the charging history for my battery and for the majority of the time it sits between the 40% to 60% charged level. According to the histogram they showed me, it's only been 100% charged for a total of 5 hours of its entire life so far! They say, based on my driving habits, I need to use a trickle charger. I drive my car nearly every day, but it's usually 12 miles to work, 12 miles back home, and whatever errands I do in between. Using a trickle charger sounds highly inconvenient to have to deal with day-to-day.

The dealership tells me that the Intelligent Battery Sensor (IBS) is fine and that the battery cable/terminal recall does not apply to my vehicle. They said the car is designed to not start recharging the battery until after 30 minutes of sustained driving. This seems odd to me and very dumb if it's true. If it's true, that would mean that my normal driving would hardly ever allow for the battery to be recharged. I would venture to say that most people's normal driving excursions are less than 30 minutes. Why would BMW design a vehicle that doesn't start recharging the battery immediately? This doesn't make sense, does it?

[fbm3cab]

Same thing happened to me and BMW good willed me a new battery even though my "driving profile" indicated that I didn't drive long enough trips to charge it.

I use a trickle charger now, but only now and then when I know I have been doing a lot of short trips or the car is sitting in garage for extended times in the winter months.

Just hook it up to a charger once or twice a week, it only takes a half minute to hook it up.

[skypx]

Originally Posted by 330iTiAg

I have a low mileage 2011 E92 M3 that I bought new. It has less than 16K miles on the clock. Just recently, I've been getting low battery charge warnings about 30 seconds after shutting off the engine (while still listening to the radio). About another 15 seconds later and everything powers down automatically.

It’s been really cold lately, so I took my car in to have the battery checked. The dealership (which I trust) tells me that they looked at the charging history for my battery and for the majority of the time it sits between the 40% to 60% charged level. According to the histogram they showed me, it's only been 100% charged for a total of 5 hours of its entire life so far! They say, based on my driving habits, I need to use a trickle charger. I drive my car nearly every day, but it's usually 12 miles to work, 12 miles back home, and whatever errands I do in between. Using a trickle charger sounds highly inconvenient to have to deal with day-to-day.

The dealership tells me that the Intelligent Battery Sensor (IBS) is fine and that the battery cable/terminal recall does not apply to my vehicle. They said the car is designed to not start recharging the battery until after 30 minutes of sustained driving. This seems odd to me and very dumb if it's true. If it's true, that would mean that my normal driving would hardly ever allow for the battery to be recharged. I would venture to say that most people's normal driving excursions are less than 30 minutes. Why would BMW design a vehicle that doesn't start recharging the battery immediately? This doesn't make sense, does it?

Using a battery charger can be inconvenient but it will save you a trip to the dealership (more inconvenient IMO). Here are some key points to remember;

1. AGM batteries typically take at least 8 hours to fully charge. You will run out of gas long before the battery is fully charged while driving (not sure if its even possible to get the battery up to 100% while driving).

2. It's your daily driver so you may only need to charge the battery once or twice a month.

3. Connect the charger after your last trip of the day and it will be ready to go when you leave for work in the morning.

I use and recommend the CTEK MUS 4.3 but I'm sure any AGM aware charger will meet your needs. Good luck.

[spdy330]

I just had my battery replaced a few weeks ago as it was low on voltage. My car is not a daily driver. 15k in 2.5 years. I went out and purchased the CTEK 7002 and it seems to be working great. Since my car is a weekend cruiser I keep in plugged in during the week. It is actually easier than you think and takes less than a minute to connect. I open the hood and connect it to the terminal there and then plug it in the receptacle as it is directly in front of my car. Close your hood to till you hear it click (not all the way) and your done. I have no complaints as long as it keeps my battery in optimum condition.