[rankizi]

I need to leave the car parked for 3 weeks.
This is a standard BMW M2 2016.

I cannot use battery tender because no power is nearby.

Should I disconnect my car's battery for that period?

[Averagej0e]

Drive your M2 on a freeway for 30 minutes and the battery should be fine for 3 weeks. I did it with my old E39 540 and had zero problems starting the car.

[greasypeanut]

i have left my dd m2 several times for 3 weeks at a time. i have not noticed anything negative not being on a tender or disconnected.

earlier this year i had to leave it for 6 weeks and got a battery tender. i plan on using the battery tender from now on for those multiple week business trips only because i have it and its extremely easy for me to set it up.

[M2guru]

I think I read somewhere that the car uses less battery when it is locked...so you might want to lock it.

[detroitm2]

3 weeks is nothing. What are you concerned with?

[heavyD^2]

As said above 3 weeks is nothing to be concerned about unless the weather is extremely cold for the duration.

[JRF]

the battery will be low at 3 weeks. i've been running the OEM battery charger every 3-4 weeks if it has been sitting idle.

when I plug it in after 3 weeks it will show 2/5 on the battery meter and take about 24 hours to bring it back up to 5/5.

this thread just reminded me that i just passed the 3 week mark and i'm going to go plug it in now.

[2+3=5]

I've left it for 4 weeks in the garage with no problems. Started right away no low battery issues

[Anthony1s]

Originally Posted by rankizi

I need to leave the car parked for 3 weeks.
This is a standard BMW M2 2016.

I cannot use battery tender because no power is nearby.

Should I disconnect my car's battery for that period?

Depends on your climate and the condition of the battery. If it's gonna be above 45 fahrenheit or so, I think it will be fine.

[JRF]

Originally Posted by 2+3=5

I've left it for 4 weeks in the garage with no problems. Started right away no low battery issues

the car will start no problem after 4 weeks but the battery will be low and a short drive will not properly recharge it. so as long as you are taking a nice cruise after 4 weeks I would think you'd be fine.

as mentioned above, I just ran down to the garage and plugged in the BMW charger on mine. it has been sitting indoors for 25 days without being started and the charger registered 2/5.

[Cadillac]

Originally Posted by rankizi

I need to leave the car parked for 3 weeks.
This is a standard BMW M2 2016.

I cannot use battery tender because no power is nearby.

Should I disconnect my car's battery for that period?

I am away on business regularly over 3 weeks, last trip was 5 weeks...starts up first time every time.
Over 18 months of ownership so far probably been away for long trips at least 10 times.

[nachob]

Originally Posted by rankizi

I need to leave the car parked for 3 weeks.
This is a standard BMW M2 2016.

I cannot use battery tender because no power is nearby.

Should I disconnect my car's battery for that period?

Yes! Even if it starts it will be low and being low is not good for the battery. You will hear people say all sorts of stuff. I ran my car low on oil for years no problem. That doesn't mean you aren't taking 2 years off the life of the engine in the end. Batteries are happy charged. They are unhappy uncharged. The better choice of you can't trickle it is simply unplug it. So easy to do the right thing. Good luck.

[F87source]

Like everyone has said before I have also left my car for 2 weeks without any battery issues. I had it sit for 2 months (doors not locked) without any issues, car did say battery was low when I put it in acessory mode but it still started fine.

[Evil///M]

What about 3-4 months?

[F87source]

Originally Posted by Evil///M

What about 3-4 months?

Yeah in a period that long I'd recommend either intermittent starting, if it's not possible unplug the battery or use a battery tender.

I don't think it'll last that long especially if the alarm system is on. It might be able to last that period time and enter accessory mode but it may not have enough power to start the engine.

[x7289155]

I tender mine for more than 3 weeks. the idle power kills it.

the easiest way to know the battery is low, is if your start stop engine feature is NOT working as quick as before.

with a fully fresh charged battery the car shuts down quickly on every stop.

[F87source]

Originally Posted by x7289155

I tender mine for more than 3 weeks. the idle power kills it.

the easiest way to know the battery is low, is if your start stop engine feature is NOT working as quick as before.

with a fully fresh charged battery the car shuts down quickly on every stop.

The easiest way would actually be a multimeter. Then the car telling you it's low on the dash.

[x7289155]

Originally Posted by F87source

The easiest way would actually be a multimeter. Then the car telling you it's low on the dash.

U can't test a battery with a multi meter.

U need to load test it.

[F87source]

Originally Posted by x7289155

U can't test a battery with a multi meter.

U need to load test it.

You certainly can test a battery with a multimeter, sub 12 volts means the battery is really low and likely won't be sufficient to crank the car. Nearing 12 volts means it's getting low and some features like auto start stop, or prolonged useage if the radio in accessory mode may be compromised.

[pruettfan]

It will be fine, just left mine for 3 unplanned weeks and it was not an issue. I normally put it on the tender though. If your just doing it for one 3 week period I don't see an issue, if you are driving the car less often than not that might be a different matter.

[F87source]

Originally Posted by pruettfan

It will be fine, just left mine for 3 unplanned weeks and it was not an issue. I normally put it on the tender though. If your just doing it for one 3 week period I don't see an issue, if you are driving the car less often than not that might be a different matter.

+1

If possible leave the car without the alarm system on and doors unlocked to prevent any unnecessary battery drain (little alarm light), and before you store it drive it hard to fully charge the battery.

[akkando]

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