[bmbweber]

Leaving for vacation to Europe for 3 weeks, car will be sitting in my garage, should I leave it on a trickle charge or will it be fine?

[vanbmw]

It will be fine. If it was colder outside maybe it would be an issue but not at this time of year.

[Katin]

You should hook up the battery once in a while anyway. Replacements are very expensive and it has been advised and proven to be a good idea to charge it from time to time.

[jd_perspective]

only if you are in Antarctica

[chiefneil]

Not strictly necessary but do it if it makes you feel better (it won't hurt).

Edit: Removed my suggestion about battery reconditioning. That may not be recommended for AGM batteries.

[wrickem]

Your car will be fine. My cars routinely sit longer than that without any problems (till I just opened my big mouth).

[Billfitz]

It may not help to put it on the charger but it can't hurt either.

[Michael Schott]

Originally Posted by Katin

You should hook up the battery once in a while anyway. Replacements are very expensive and it has been advised and proven to be a good idea to charge it from time to time.

Where has this been proven? Do you understand the function of the alternator?

[Climb Mode]

It will be totally fine.

[Katin]

Originally Posted by Michael Schott

Where has this been proven? Do you understand the function of the alternator?

Lots of threads out there talking about this. Frequent Short trips do not allow the alternator to do its work. Efficient Dynamics and lots of tech are hard on the batteries.

[Michael Schott]

Originally Posted by Katin

Lots of threads out there talking about this. Frequent Short trips do not allow the alternator to do its work. Efficient Dynamics and lots of tech are hard on the batteries.

I agree with the short trips but in normal driving there is zero reason to have to charge the battery. It's 2017 for goodness sake and modern batteries have plenty of capacity and are fully charged in day to day driving. I owned (leased) 3 different 3 series over a 9 year period and about 140,000 miles and never had a battery issue.

[EBS0712]

You will be fine but the investment in a Battery Tender Jr. for about $25 is well worth the investment in battery life. I use mine whenever I go on an extended trip and the battery is always fully charge but NEVER overcharged upon my return.

[HighlandPete]

Originally Posted by Michael Schott

I agree with the short trips but in normal driving there is zero reason to have to charge the battery. It's 2017 for goodness sake and modern batteries have plenty of capacity and are fully charged in day to day driving. I owned (leased) 3 different 3 series over a 9 year period and about 140,000 miles and never had a battery issue.

It's all about driving profile and the energy management, not charging the battery to 100%. Typically with efficient dynamics 'energy management' the battery is only at ~75 - 80% SOC. This allows for the alternator to work on the over-run.

If the driving profile doesn't support much over-run 'regeneration' we can find the battery never gets any real 'boost'.

Due to this thread, I've just run a 'smart charge' on my battery, this afternoon, to see its condition. This is after some weeks of normal use in favourable driving, including 90 mile drives. Battery was lower than 80%, at the start, typical of what I find any time I've run a charge.

I've kept my battery topped up over winter months, this is the first check since early spring. BTW, battery is now into its seventh year. Says something for giving it the occasional boost through the winter months.

[DrifterX]

I went away for almost 3 weeks recently - zero issues with battery drain when I got back after sitting in my garage.

You should be fine but I agree a battery tender is always nice to have - just be careful not to get a cheap one as the components that prevent overcharge may eventually fail due to cheap components. Car batteries don't have over charge protection like your phone does - it relies on the charging source to do that.

[Katin]

Originally Posted by HighlandPete

It's all about driving profile and the energy management, not charging the battery to 100%. Typically with efficient dynamics 'energy management' the battery is only at ~75 - 80% SOC. This allows for the alternator to work on the over-run.

If the driving profile doesn't support much over-run 'regeneration' we can find the battery never gets any real 'boost'.

Due to this thread, I've just run a 'smart charge' on my battery, this afternoon, to see its condition. This is after some weeks of normal use in favourable driving, including 90 mile drives. Battery was lower than 80%, at the start, typical of what I find any time I've run a charge.

I've kept my battery topped up over winter months, this is the first check since early spring. BTW, battery is now into its seventh year. Says something for giving it the occasional boost through the winter months.

This is the type of experience I have based my habits on. What can occasionally topping off the battery hurt? Well said my Bimmer friend.

[eluded]

Just put it on the charger/trickle when you come back

[MSCD]

I would charge it up before you go if you don't want to leave it on and then again as soon as you get back. I did that with my E93 ad that isn't my daily.

Also if you have an alarm that will drain the battery if you are leaving it locked and activated....

Enjoy Europe!

[capt_slow]

I was away for over a month and just left my car locked in the garage. It started right up when I got back.

Doesnt hurt to charge up the battery before you go. I think leaving it locked helps more because it goes into some sort of power saving sleep mode.