BMW 3 Series Compact - Battery conditioner/Charger - meldrew

The original battery lasted eleven years including the winters of 2010. I got a new Varta battery just under a year ago and not having used the car for a few days it failed to start in near freezing temperature. Additionally the car no longer does a high mileage probably 30 to 40 a week.

I have "old fashioned" battery chargers for a short charge and a couple of hours got it going. I think I need a more modern unit but some of the conditioners seem weak for charging although time is not normally an issue.

Can anyone recommend one?

This looks promising and I assume that if connected for long enough it would recharge a "flat" battery


BMW 3 Series Compact - Battery conditioner/Charger - elekie&a/c doctor

These are top quality product and will do the job.It will charge a flat battery,but may take 24 hrs or more to bring it back to strength.

BMW 3 Series Compact - Battery conditioner/Charger - gordonbennet

That CTEK is probably too small for the battery fitted to the BMW and the next model up might be a better bet (up to say 100ah battery), though i'm surprised a newish Varta has gone completely flat unless it was underspecified to begin with.

Lidl had their £13.99 smart chargers for sale a couple of weeks ago, and very good they are too, similar in all ways to the CTEK's but maybe not as high quality, i have one and it's done the business for me on several batteries...also have the larger CTEK smart charger and that does the job every bit as well as the Lidl jobbie.

Edited by gordonbennet on 22/01/2015 at 19:06

BMW 3 Series Compact - Battery conditioner/Charger - Fernando P

I have had a CTEK Multi XS 3600 for some years now and it is for charging batteries 1.2 - 120AH. Benefits are that the battery can be charged in situ without damage to the vehicle's electrics, the charger left "on" when the vehicle is not being used and is easily disconnected. I use it thus to charge/maintain a Type 100 diesel engine battery. There are cheaper versions around but I recommend this one without hesitation.

BMW 3 Series Compact - Battery conditioner/Charger - meldrew

Thanks for speedy replies! It looks as if a CTEK product is the way to go.

THe battery is a Varta D24 60Ah which appears to be correct for the vehicle. I am surprised it lost its charge in less than a week of cold weather as there have been no previous electrical problems that might account for it. I might get it checked out by my local supplier next week.

Will report back if any news!

BMW 3 Series Compact - Battery conditioner/Charger - meldrew

A quick update after buying a CTEK MXS 5.

Had a check at my local garage/supplier who said battery was OK but needed charging. Lack of use in freezing temps?

Left it connected to the CTEK for two days and it went through the motions. Checked battery with a voltmeter for the next few days and got voltages varying from 13.5v to 15.5v with an electronic meter. Seems OK, so far so good.

Also bought the Comfort Indicator and charging socket to plug into the cigarette lighter socket. Great for charging but the minute the charger is turned off it goes immediately to red! Strange as putting in a seldom used MGB it lit up happily on green. Baffled by that one.

BMW 3 Series Compact - Battery conditioner/Charger - jc2

Some lighter sockets are wired thro' the ignition;some cars give you the option of always live or only live with ignition

BMW 3 Series Compact - Battery conditioner/Charger - meldrew

Both cars are live with the ignition off if running a tyre pump is a yardstick.

Conversely Mrs M's late model BMW is only live with the engine actually running!

BMW 3 Series Compact - Battery conditioner/Charger - Wackyracer

Might be time to check the wiring in that case, If you cigar socket is permanently live and the indicator goes red when the charger is switched off, This could be a high resistance in the wiring to the battery in which case the alternator might also not be charging the battery as it should.

I have a Ctek charger and it is superb. The only thing I didn't like about it was the fuse in the plug was a 13amp and that is well over rated for it.


Value my car