[un1eash]

So apparently my 2008 320D E92 doesn't like 15-25 minutes trips twice a day and after about 2 weeks from the battery being fully charged I get battery warning messages and lose the clock and trip computer settings.

I can't believe that this car can't keep a charge as I've never had a problem with any other cars I've owned. Even after a long trip the battery still doesn't charge, BMW say the battery is fine and its my driving style.

So I have a Ctek trickle charger. I've currently got it connected directly to the battery but just read some people advise against this and I should use the jump start posts under the bonnet. Which is it?

Anyone else have problems with short trips, should I get onto BMW about changing the battery.

[Soul_Glo]

No problems here. My morning journey is 23 miles in 35 minutes on A/B roads. My way back is 45-60 minutes over 25 mile route. Even when I was forced to do two ten minute trips for one month it was okay. If yours is a 2007-2008 I would say it may well be time to replace the battery.

[Russ200]

Change the battery I had this a month or so bmw checked it and battery was ok they wanted to keep it over night for drain test but I needed it for work so told them to change it anyway it hasn't skipped a beat yet and start stop works all the time now.

[Robin330i]

I have mine on a ctek trickle charger on mine without any issues

[Waspo]

Don't charge directly to the Battery, Use the charging/Jump points under the Engine Bonnet!!!

Can't remember where i read this, but i think it was on here!

[un1eash]

Some say use the battery, others the jump points. There doesn't seem to be a definitive answer on which to use. Will try BMW again and see what they say about a replacement battery.

[Robin330i]

Originally Posted by Waspo

Don't charge directly to the Battery, Use the charging/Jump points under the Engine Bonnet!!!

Can't remember where i read this, but i think it was on here!

Mine has been fine for the past 3mths connected to the battery directly.

[alzieboy]

Read this thought it was worth sharing maybe

Locate a Suitable Ground Location
Finding a suitable location to attach the negative terminal of your charger is the key to safe and effective completion of your trickle charger circuit. Ideally a spot of bare metal on the frame, or a large bolt attached to the chassis or engine block should be used, but if one cannot be located, a section of the frame that is free of excessive dirt, grime and oil will suffice. The negative terminal on the battery should never be used, as it can cause an explosion or fire.

[Waspo]

Originally Posted by Robin330i

Mine has been fine for the past 3mths connected to the battery directly.

Originally Posted by alzieboy

Read this thought it was worth sharing maybe

Locate a Suitable Ground Location
Finding a suitable location to attach the negative terminal of your charger is the key to safe and effective completion of your trickle charger circuit. Ideally a spot of bare metal on the frame, or a large bolt attached to the chassis or engine block should be used, but if one cannot be located, a section of the frame that is free of excessive dirt, grime and oil will suffice. The negative terminal on the battery should never be used, as it can cause an explosion or fire.

I rest my case m'laud !

[Soul_Glo]

Originally Posted by alzieboy

Read this thought it was worth sharing maybe

Locate a Suitable Ground Location
Finding a suitable location to attach the negative terminal of your charger is the key to safe and effective completion of your trickle charger circuit. Ideally a spot of bare metal on the frame, or a large bolt attached to the chassis or engine block should be used, but if one cannot be located, a section of the frame that is free of excessive dirt, grime and oil will suffice. The negative terminal on the battery should never be used, as it can cause an explosion or fire.

While this holds true for charging... The CTEK is quite safe and can be connected directly to the battery. Further to this our batteries are ventilated. You could even touch the positive and negative points on the CTEK together and it won't spark. At the end of the day even if you try different ground points and have no joy you are probably looking at a new battery. Before you do buy a fresh battery it is worth investigating any possible drain. The resting voltage of your battery should be no lower than 11.9v Charge it up fully... Leave it a day or two if you can and check the resting voltage.

[Hulla the Hulla]

Originally Posted by Broken_Gearbox

While this holds true for charging... The CTEK is quite safe and can be connected directly to the battery. Further to this our batteries are ventilated. You could even touch the positive and negative points on the CTEK together and it won't spark. At the end of the day even if you try different ground points and have no joy you are probably looking at a new battery. Before you do buy a fresh battery it is worth investigating any possible drain. The resting voltage of your battery should be no lower than 11.9v Charge it up fully... Leave it a day or two if you can and check the resting voltage.

this

I have my Ctek convenience cable attached directly to the posts of my battery with no issues. They also do ones that fit in the power socket so I have to assume that where you connect is less important than the quality of the charger. The Ctek units are pretty advanced and very safe.

[un1eash]

I've wired it up to the jump start posts under the bonnet now which makes it a little easier to access in relation to the power socket when parked up. Its been on charge for at least 20 hours over the weekend and still only showing 12.5v and the Ctek hasn't gone green yet. This I believe is about 80% full and should reach 12.7v+ when 100%.

I'm going to just replace the battery I think as plugging it in every couple weeks isn't ideal.

[Waspo]

Originally Posted by un1eash

I've wired it up to the jump start posts under the bonnet now which makes it a little easier to access in relation to the power socket when parked up. Its been on charge for at least 20 hours over the weekend and still only showing 12.5v and the Ctek hasn't gone green yet. This I believe is about 80% full and should reach 12.7v+ when 100%.

I'm going to just replace the battery I think as plugging it in every couple weeks isn't ideal.

Have you got the ctek set to 'Reconn'? or just charge? Setting to recon (Reconditioning) is good for a failing battery.

Ultimately, you will have to look at the reasons why it is failing? Old Age, Battery drain, or alternator issues. Not an expert on this, but in all walks of life you should always look for a reason for a failure, and not just the cure!!

[un1eash]

My Ctek MXS 3.6 doesn't have a recon setting, you just select motorbike, car battery or cold weather/agm battery. It will bulk charge up to 80% then do what it calls absorption up to 100% where it reduces the current to maximise the capacity. Once fully charged it will pulse charge to keep it topped up.

I've tested the basics but not sure on how to test the intelligent battery system. I have a feeling the cars on its original battery still.

[Aragorn30d]

Your alternator should easily be keeping the battery topped up with that sort of use.

If it was a 2 minute journey twice a day then sure you might start having problems, but 15mins is plenty.

Either the battery or charging system isnt working properly.

[un1eash]

I need to get a propper drop test done on the battery but as for voltages, it's 14v+ when engine is running. Straight after turning the engine off it reads 12.7v but slowly decreases and after a few hours reads 12.2v.