Can you disconnect a e53 battery for storage???
 

Dead battery again 2005 X5. I think the last time it was on the charge was Thanks Giving (maybe before that). Battery reads 1.6V it is really dead.



So question 1. If you are storing an X5 is there a problem disconnecting the battery indefinitely. If so like what?



Question 2 If I could disconnect the battery indefinitely. Given the battery is completely dead. Is there something I need to do or check before disconnecting the battery??? Like at least start the car, run the engine??? I hear there may be an issue air suspension???

No problem disconnecting the battery for storage....The better option is to get a battery tender...assuming you have power near the X5.. And If you don't have power near the X5, you can buy a solar-powered battery tender...there are a couple on Amazon with good reviews...

Batteries are expensive..

BMW has rules for how to maintain a battery for long term storage.

At least twice a year a thread on xo relates to can't start after long term battery disconnection. Either the lock code through the MID or three EWS loses sync. Either can be resolved but I would know if you have a start code set and what it is first and have access to a scanner that can sync EWS before disconnect battery long term.

These cars don't seem to respond well to anything other than normal operating parameters. I had mine in the garage for quite a long time, couple of years actually. I had a battery maintainer on it the entire time to avoid any issues. Still, when I put it back in service, the nav computer was dead, no video signal. I felt lucky that was the only thing as replacing it was literally a five minute fix :-)

A battery maintainer is definitely the better way. CTEK seems to be a decent brand (Porsche recommends it for their vehicles).

First, find out how many amps are being drawn after 16 min. Battery tenders start at 750 milliamps. I'm looking at a 4 amp version. Mostly to charge the battery back up to full power then maintain it.

Definitely get that battery charged up before setting it aside or leaving it in place and disconnected. It already lost some of its life by going all the way down to 1.6V, and will lose even more if it spends a lot of time at that low voltage.

As far as the car itself goes (vs. the battery), it should be happy with either a charged 12+V battery, or with no battery at all. In between is not so good. A charger with no battery installed could cause problems. Each time you connect or disconnect the battery to the car, there is the chance for a voltage spike causing issues. On most cars, a trick is to turn the parking lights on to dampen any spike, but I'm not sure if the BMW LCM wizardry gets in the middle of that for these cars.

Also - charge it fully, then start. Don’t make the alternator charge the battery - that is bad for the alternator.

I would get a good battery maintainer,and not let the X5 sit without any voltage .If you can I would start it once a month at least.to get oil up into the engine components.

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having 4-6 vehicles on hand requires battery maintainers
 

When I first traded for my X5, I immediately (after two days of ownership) hooked up a battery maintainer on it, before I'd even driven it 10 miles. I intended the X5 to be my "family car" (for trips to visit the inlaws' ranch), or a "inclement weather" (AWD is better than the other cars/trucks' 2WD or FWD). As such, it sits a lot, with only about 250 miles in the last eight months. After reading about and experiencing some BMW glitchy electrical problems already, I will never allow the battery to drain down, if at all possible.

Right now, my car/truck inventory is five (one car undergoing repair, for the last eight months); over the last thirty years, I've had as many as six, but never less than four. Except for one dismal time, when we had only two, and had to borrow friend's & relatives' cars to get me to work (120 mile round-trip), and the wife to school, then work (40 miles).

Both vehicles we had failed on the same day (electrical on both); and we were both recovering financially after divorces, and just moved into our house in the country (semi), away from possible carpools or public transport. It was a real scramble to get two cars to use before midnight!

I immediately vowed to never get in that situation again, and soon acquired a back-up truck, then another car just for her, then another car (soon converted to a car show weekender, then dedicated drag-car)...and so on. Six (two retired, awaiting repairs, and the race car sitting unused in the garage, all for a dozen years) being the peak; the X5 became #6 if only for a day, when the race car went away.

Except for the two retired needing-repair cars I parked out back by the sheds (gone in '17), all other cars/trucks are always kept charged with de-sulfating battery maintainers, 24-7 365. Even the race car, though never able to be a streetable back-up, always had charged-up batteries (2).

Sometimes a vehicle might sit up to three months without being needed, though I would start them up usually after two months in warm weather, or one month in colder weather (usually after the anti-freeze check). The race car in the garage only got started every year (I also checked it for possible hydro-locking, before cranking it).

By using the battery maintainers, I've been able to keep the batteries usable for up to 11.5 years; the average is only about 9 years, and only one failed to make it past 5. Maintainers are money well-spent.

The reason why pulling the battery off a BMW and leaving it off is NEVER a good idea, is because many of the multiple sensors, comp modules, may never wake up again when the battery is reinstalled.

At least 4x a year somebody on xo either can't start there car or had some horrible electrical gremlin happen after long term of dead battery. Zero percent chance I would leave and BMW without a battery connected other than momentarily to replace it. (many will hook up a maintainer or parallel battery at the b+ during the swap to never have the voltage drop)

^ that is the recommended shop procedure

Everyone here knows it is a pain to d/c the ground cable in the trunk bc of the spare tire lying on top of the battery.

Let's say one just wants to prevent a battery drain and do not have a charger (sometimes ppl park at airport for wks) etc...

Does anyone here know the fuse(s) that feed whatever item (such as ECU etc. that creates parasitic drain) that one can simply remove to prevent current drain? Then once you return (let's say at the airport etc), simply reinsert the fuse(s) and drive away?

Thanks!

Bold of you to assume only ONE thing parasitically drains these cars ��

The risk is throwing out your ews sync. BMW specifically demands not to let battery go dead


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Let's say we pull the fuses for ECU and GM modules, is it sufficient to avoid battery drain?