Battery disconnect?

Tipper · 08-22-2011, 05:01 AM

I'm taking a long holiday this winter (2 months+) and the car will be locked away in an unheated garage. I know about leaving it with the brakes off but what about the battery?

It's the original 2007 battery and seems to be OK to me but if I leave it connected it will obviously go flat and as I understand it the battery may never recover due to being left flat in very cold weather. (based on my son's battery last winter that wouldn't recharge after being left over 6 months!)

I feel I should get it inside out of the cold and put it on a maintenance charger.

So, should I disconnect and remove it? Can't charge it in the garage as there's no power.

If I leave it disconnected will this cause problems when I reconnect?

Any advice?

Also what's all that clutter on top of the battery? BMW over-engineering or something essential?

Thanks

xenon · 08-22-2011, 05:04 AM

Stuff on top of the battery is the condition monitoring stuff. I'd leave it connected personally.

M3-FAST · 08-22-2011, 05:09 AM

I use a battery conditioner on my track Scooby. A small lead with a socket on is attached to the battery terminals and I have this poking out through the gap between the grille and the headlamp.

I just keep it plugged in when not in use and it keeps the battery tip top. When I want to move the car it is easy to disconnect without even opening the bonnet. When used in a track day I just cable tie the short lead around the battery holder.

Cost about 30 quid if I remember correctly.

creepy coupe · 08-22-2011, 08:01 AM

http://www.ctekchargers.co.uk/ctek-mxs-10.php

I have one of these for mine, the fly lead stays permanently connected to the battery and has a nice easy push connecter to the charge lead. I trickle charges and self-monitors, you can leave it connected indefinitely

kaishang · 08-22-2011, 08:41 AM

Meh, I've left all sorts of vehicles unused for months at a time. They always seem to start right up again as soon as I get back.

m1bjr · 08-22-2011, 12:46 PM

Quote:

Originally Posted by creepy coupe

http://www.ctekchargers.co.uk/ctek-mxs-10.php

I have one of these for mine, the fly lead stays permanently connected to the battery and has a nice easy push connecter to the charge lead. I trickle charges and self-monitors, you can leave it connected indefinitely

+1

I have the MXS 5 version too.

It managed to recover a totally knackered old leisure battery too

But I wouldnt bother doing anything to the car for such a short time like 8wks.

Tipper · 08-23-2011, 05:58 AM

Quote:

Originally Posted by creepy coupe

http://www.ctekchargers.co.uk/ctek-mxs-10.php

I have one of these for mine, the fly lead stays permanently connected to the battery and has a nice easy push connecter to the charge lead. I trickle charges and self-monitors, you can leave it connected indefinitely

If I had power in the garage then that would be my choice, unfortunately I don't. Therefore do I remove the battery and maintenance charge it indoors?

My concern is what happens when the battery goes flat/is removed?

Does refitting it then require BMW to get it re-installed/activated/adapted/'anything else' that BMW can charge for?

AlwynMike · 08-23-2011, 06:53 AM

My 5er lives outside all year, and is unstarted for long periods whilst I'm away, so I shouldn't worry about it (the original 2004 battery was replaced a couple of months ago!)

If you have a concern, get a solar charger - you won't need a big one so you won't need a regulator (extra cost!) - just a window and a bit of wire.

Mike

08-22-2011, 05:01 AM	#1
Tipper Private First Class 9 Rep 127 Posts Drives: 2007 E91 320d SE auto Join Date: Jan 2009 Location: Devon, UK iTrader: (0)	Battery disconnect? I'm taking a long holiday this winter (2 months+) and the car will be locked away in an unheated garage. I know about leaving it with the brakes off but what about the battery? It's the original 2007 battery and seems to be OK to me but if I leave it connected it will obviously go flat and as I understand it the battery may never recover due to being left flat in very cold weather. (based on my son's battery last winter that wouldn't recharge after being left over 6 months!) I feel I should get it inside out of the cold and put it on a maintenance charger. So, should I disconnect and remove it? Can't charge it in the garage as there's no power. If I leave it disconnected will this cause problems when I reconnect? Any advice? Also what's all that clutter on top of the battery? BMW over-engineering or something essential? Thanks
	Appreciate 0 Tweet Quote

08-22-2011, 05:04 AM	#2
xenon Major General 1397 Rep 8,083 Posts Drives: 2021 G21 330i M-Sport Join Date: Jun 2008 Location: Coventry iTrader: (0)	Stuff on top of the battery is the condition monitoring stuff. I'd leave it connected personally. __________________ Ian Current: 2021 G21 330i M-Sport Previous: 2018 A6 Avant S-Line MMI+, 2014 F31 320d M-Sport, 2013 F10 520d M-Sport, 2011 F10 530d M-Sport, 2008 320i M-Sport Coupe, 2002 325i, 2001 318i valvetronic, 1998 318i, 1996 525i, 1990 Porsche 944S2
	Appreciate 0 Quote

08-22-2011, 05:09 AM	#3
M3-FAST Defected to the dark side..... 210 Rep 5,795 Posts Drives: BMW M5 LCi Join Date: May 2007 Location: Stafford, UK iTrader: (11) Garage List 2009 E90 M3 [10.00] 2007 325i M-sport C ... [9.00]	I use a battery conditioner on my track Scooby. A small lead with a socket on is attached to the battery terminals and I have this poking out through the gap between the grille and the headlamp. I just keep it plugged in when not in use and it keeps the battery tip top. When I want to move the car it is easy to disconnect without even opening the bonnet. When used in a track day I just cable tie the short lead around the battery holder. Cost about 30 quid if I remember correctly.
	Appreciate 0 Quote

08-22-2011, 08:01 AM	#4
creepy coupe Lieutenant General 1867 Rep 13,043 Posts Drives: BMW M340I G20 Join Date: Aug 2007 Location: UK iTrader: (2) Garage List 2015 BMW 435d [0.00] 2009 335i [0.00]	http://www.ctekchargers.co.uk/ctek-mxs-10.php I have one of these for mine, the fly lead stays permanently connected to the battery and has a nice easy push connecter to the charge lead. I trickle charges and self-monitors, you can leave it connected indefinitely Last edited by creepy coupe; 08-22-2011 at 08:16 AM..
	Appreciate 0 Quote

08-22-2011, 08:41 AM	#5
kaishang Colonel 54 Rep 2,197 Posts Drives: 2010 E90 330d Join Date: Jul 2010 Location: London iTrader: (0)	Meh, I've left all sorts of vehicles unused for months at a time. They always seem to start right up again as soon as I get back.
	Appreciate 0 Quote

08-23-2011, 06:53 AM	#8
AlwynMike Lieutenant Colonel 337 Rep 1,660 Posts Drives: F36 440i GC. Join Date: Sep 2010 Location: Lincolnshire Flatlands iTrader: (1)	My 5er lives outside all year, and is unstarted for long periods whilst I'm away, so I shouldn't worry about it (the original 2004 battery was replaced a couple of months ago!) If you have a concern, get a solar charger - you won't need a big one so you won't need a regulator (extra cost!) - just a window and a bit of wire. Mike
	Appreciate 0 Quote