Battery when garaged over winter

ronk · Post by **ronk** » Mon May 21, 2018 11:54 pm

Busterboo wrote: ↑Mon May 21, 2018 10:58 pm
mentalnerve wrote: ↑Sun May 13, 2018 12:37 pm I've got ... the ctek mxs7 £80 with the cigarette lighter plug ...
Can you use it on an E89 through the cigarette lighter?

The book instructs you to conect a charger via the under bonnet posts.
With the amount of electronics these cars have I won’t argue with their (BMW) instructions.

My charger was an cheapo under £10 job from Makro many years ago - designed for liesure batteries and golf carts - it cycles the battery but doesn’t fully charge nor discharge, something like 12.5v up to 13.5v it’s done the job over the last seven or eight years .
I used it over last winter and it started on the button in May - I did put the voltmeter across the posts once in a while and it was always in a positively charged state.

Busterboo · Post by **Busterboo** » Tue May 22, 2018 10:10 am

Thanks, ronk.

I asked mentalnerve about using the cigarette lighter socket for a CTEK, because mine's only live with the ignition on and so can't be used. (The same was true of a recent 4.2 Jaguar but, very conveniently, I could use the CTEK through the lighter socket on the 911.) I wondered, however, if he has an E89 variant with a live socket or if his has been modified.

ronk · Post by **ronk** » Tue May 22, 2018 10:56 am

The ‘book’ is very specific about using the under bonnet pins and it concerns me that conecting via the fag lighter might be powering up some component from the wrong direction.

I didnt find it a hardship to lift the bonnet and dump the charger there. As the car was garaged, I always left the bonnet ajar so I didn’t forget the car was on charge.

Busterboo · Post by **Busterboo** » Tue May 22, 2018 10:58 am

ronk wrote: ↑Mon May 21, 2018 11:54 pm The book instructs you to conect a charger via the under bonnet posts.
With the amount of electronics these cars have I won’t argue with their (BMW) instructions.

I'm thinking of attaching a BMW 'Battery Comfort Indicator Eyelet' (a catchy name) permanently and running the CTEK into the boot.
https://shop.bmw.co.uk/INTERSHOP/web/WF ... =PID_86039

ronk · Post by **ronk** » Tue May 22, 2018 11:25 am

The product seems to make a mockery of their instructions to connect under the bonnet

Busterboo · Post by **Busterboo** » Tue May 22, 2018 7:12 pm

Yes!

enzed4 · Post by **enzed4** » Wed May 23, 2018 9:30 am

The charger I bought came with an adapter to mount by the front grille for easy connect/disconnet, but I didn't want it sitting so exposed to the elements (water spraying in from other vehicles etc) so I mounted it inside the engine bay. Once connected, I can close the bonnet (feeding the cable through the gap between the headlight and bumper) and leave it on charge as long as it needs

: Charger02.jpg (205.39 KiB) Viewed 839 times

And since I know how good my memory is, so I don't drive out of the garage with the charger still attached, I leave this subtle notice hanging on the wiper stalk

The attachment Charger03.jpg is no longer available

Mark R · Post by **Mark R** » Wed May 23, 2018 11:08 am

Get a new CTek and it should come with a quick connector that you attach to the battery, then its a simple plug in switch on and your done.

Busterboo · Post by **Busterboo** » Wed May 23, 2018 1:03 pm

I have the same. However, I assume that the advantage of this connection is that it shows when the battery charge is low:
https://shop.bmw.co.uk/INTERSHOP/web/WF ... =PID_86039

ronk · Post by **ronk** » Wed May 23, 2018 6:02 pm

Busterboo wrote: ↑Wed May 23, 2018 1:03 pm I have the same. However, I assume that the advantage of this connection is that it shows when the battery charge is low:
https://shop.bmw.co.uk/INTERSHOP/web/WF ...
=PID_86039

I don’t think I’ll bother - if an auto battery charger is fitted for hibernation periods it will look after the state of charge - if it’s reassurance that’s needed, just stick a voltmeter across the battery,

Busterboo · Post by **Busterboo** » Wed May 23, 2018 7:06 pm

For £13

ronk · Post by **ronk** » Wed May 23, 2018 7:16 pm

No doubt it’s cheap but you either trust the maintenance charger or not - so i can’t see the point - other than it’s another toy in the toybox

Red61 · Post by **Red61** » Fri Jun 01, 2018 2:47 pm

Hi,

Sorry if this is daft question but can you connect a trickle charger through the cigar lighter socket like in the old days?!

jabber · Post by **jabber** » Fri Jun 01, 2018 6:22 pm

Red61 wrote: ↑Fri Jun 01, 2018 2:47 pm Hi,

Sorry if this is daft question but can you connect a trickle charger through the cigar lighter socket like in the old days?!

I don’t think so its recomended to connect to the under bonnet points

ronk · Post by **ronk** » Fri Jun 01, 2018 7:39 pm

Busterboo wrote: ↑Mon May 21, 2018 10:58 pm
mentalnerve wrote: ↑Sun May 13, 2018 12:37 pm I've got ... the ctek mxs7 £80 with the cigarette lighter plug ...
Can you use it on an E89 through the cigarette lighter?

If the ciggie lighter socket doesn’t stay live with the ign circuit off - then No!

But remember that the book says use the under bonnet pins - they must have their reasons !

Z4-forum.com

Z4-forum.com