Battery replacement

[GrahamS4]

Does it have to be CTEK MXS-10? From a brief look on their web pages the differences between MXS-7 and 10 are the temp sensor and maximum output current.
Is it worth to go for the top model if chances are that I will never be in the need of charging a 200mAh battery?
Anyway,thanks for the info on these chargers.

If you only need to charge a typical modern car battery, the chance of it being anywhere close to 200Ah is slim. More likely 100Ah is the upper end you will see (even for the RS6) and often much less.

The MXS10 for most purposes will be overkill, but is certainly the daddy of the consumer range. If you have a motorhome and a JCB to look after as well it could be the wise choice of course! The plus side is it will charge a typical 70-100Ah battery a lot quicker than a lesser model. Keep in mind this is not much of a plus unless you intend on charging batteries from flat a lot and need to do it quickly though. Of course once you have a CTEK charger you will mostly be maintaining batteries, not charging them from flat. Negatives are the price and the charger may not be suitable for smaller batteries (motorbike for example).

I would say the MXS 5.0 will be every charger you ever need for keeping your car battery topped up (still not the lowest model you could choose for the job from the CTEK range). It will charge a 110Ah battery from flat and can maintain batteries up to 160Ah. If you go for this one make sure buy the "2014" model with the red mode button. The new MXS 5 has automatic temperature mode selection and has better support for AGM batteries (which you will find in most stop/start cars).

[GrahamS4]

It won't 'fix' the battery though.

A battery conditioner just might. Personally I would be wary of using the recondition mode (CTEK MXS 5 and up) with the battery connected to the car though, due to the extra voltage involved.

[PorkaFly]

I recently purchased a CTeK MXS5.0.v1 for use on both my RS6 and GT3RS...both big heavy duty batteries. You don't need a 7 or 10, MXS3 up will suffice in fact, but you get the 8step program/reconditioning with 5 upwards. CTek is way to go for de-salphating and reconditioning. Very impressive piece of Kit and is doing its annual recondition as I'm not using it for a few days.

PF

[GrahamS4]

I recently purchased a CTeK MXS5.0.v1 for use on both my RS6 and GT3RS...both big heavy duty batteries. You don't need a 7 or 10, MXS3 up will suffice in fact, but you get the 8step program/reconditioning with 5 upwards. CTek is way to go for de-salphating and reconditioning. Very impressive piece of Kit and is doing its annual recondition as I'm not using it for a few days.

PF

I've been using an older lower rated 4 stage CTEK, but have just ordered the new MXS 5 as I fancied an upgrade.

Reading about the recondition mode I was hesitant about using it with the battery connected (as mentioned above). Let us know how you get on with it. It would be nice to know it doesn't cause an issue with the Audi.


http://www.ctek.com/gb/en/page/support/faq

Does the battery have to be disconnected from the vehicle when it is being charged with a CTEK charger?

No, CTEK chargers cannot damage sensitive electronics. So, you don't have to disconnect the battery from the vehicle! However, you should take extra care when using Recond because the voltage is 15.8V. Most manufacturers consider everything to be fine as long is voltage is below 16V and CTEK is under that limit by a good margin, even during Recond. Note that the service life of some components is shortened by high voltage. A rule of thumb says that a light bulb's life span is halved by increasing voltage by 5%, but this is normally not any great danger. If you have any sensitive electronics for which the manufacturer warns against high voltage: disconnect them!

[PorkaFly]

I recently purchased a CTeK MXS5.0.v1 for use on both my RS6 and GT3RS...both big heavy duty batteries. You don't need a 7 or 10, MXS3 up will suffice in fact, but you get the 8step program/reconditioning with 5 upwards. CTek is way to go for de-salphating and reconditioning. Very impressive piece of Kit and is doing its annual recondition as I'm not using it for a few days.

PF

I've been using an older lower rated 4 stage CTEK, but have just ordered the new MXS 5 as I fancied an upgrade.

Reading about the recondition mode I was hesitant about using it with the battery connected (as mentioned above). Let us know how you get on with it. It would be nice to know it doesn't cause an issue with the Audi.


http://www.ctek.com/gb/en/page/support/faq

Does the battery have to be disconnected from the vehicle when it is being charged with a CTEK charger?

No, CTEK chargers cannot damage sensitive electronics. So, you don't have to disconnect the battery from the vehicle! However, you should take extra care when using Recond because the voltage is 15.8V. Most manufacturers consider everything to be fine as long is voltage is below 16V and CTEK is under that limit by a good margin, even during Recond. Note that the service life of some components is shortened by high voltage. A rule of thumb says that a light bulb's life span is halved by increasing voltage by 5%, but this is normally not any great danger. If you have any sensitive electronics for which the manufacturer warns against high voltage: disconnect them!

Sure thing...will do. I already know the battery is not knackered as at stage 4 after only a few hours, so that's good to know.

Remember on the RS6 that the battery is in the boot under the floor and you cannot affix the charger there. It has to be done on the clever plus and negative terminals inside the engine bay (top left-hand corner standing at front bumper). Nothing in the CTeK bumpf I read which concerns me or particularly warns of the above, but am now heading into the garage again to check all is well

PF

[GrahamS4]

I agree there is no such warning in the instructions, so I am probably being over cautious. Just the manufacturers change from cannot harm electronics to take extra care in the FAQ took my notice.

[MB2]

I have a C-Tek for my motorbike so thought would add a few comments in case they help... I have attached direct to the battery & that is how I charge - you can get leads with various bolt sizes from C-Tek as well as an extension lead so I think an underboot install would be perfectly feasible, or run the leads out of the car at the front as the connector is waterproof.

No problem leaving on for long periods - my bike is on charge unused all winter, although I do put the charger on a timer. On the odd occasion I have used it to charge cars it has worked fine although obviously takes a long time - mine is the XS-0.8.

Finally I wouldn't bother with the battery indicator light leads as it doesn't seem at all accurate.

[GrahamS4]

I have the comfort connect indicator attachments hardwired to both cars. I find the hardwired approach more convenient in the long run and a better solution for charging with the bonnet closed. I wouldn't go out my way to buy the indicators again, but I do like having the connector hardwired. The indicator function isn't great, unless on charge or seconds from being disconnected you never see green. Amber I take as OK and if red persists I know the battery is due a charge. Luckilly I picked them up from a show for very little. ** Edit - I remember now why I went for the indicator lead. The standard non-indicator hardwire lead does not have a fuse. Even with a water resistant connector, the potential for a short on a feed like this without a fuse did not leave me comfortable.

I have my MXS 5 now and am pleased I went for the upgrade for the additional status lights alone. One downside is the leads are much shorter than on my older CTEK. The output side being shorter in particular is a bit of a pain. The extension cable offered by CTEK will solve the problem though (already ordered one). A shame I didn't realise before I probably would have ordered the extension cable over the rubber case, but I will have both now.

[Mr V10]

Turns out the battery does need adaption/coding. And mine is kaput!

[chunky79]

Being changed under warranty? If not you can borrow my ctek mate to give it a try.

[Mr V10]

Nope, will be out of my own pocket.

[Mr V10]

Thanks for the offer btw!

[Mr V10]

Not driven the car much lately, I reckon less than 100 miles in the past two months as I've been busy and abroad, so not had a chance to have a new battery fitted and coded either.

I made a short trip in it over the weekend, and then it wouldn't start an hour later due to the battery, I got it started it and took it for a run and where it showed on the MMI it had charged to 100%, however, it was down to 50% again quite quickly on a shorter journey I did later that day.

I've just hooked up my new CTEK on the recon function and will be leaving it overnight, really clever bit of tech and I am genuinely really interested to see if it fixes it. Last time Audi had it in it flashed up 'battery fault', it is going in again so let's see if it still pops up after a night with the CTEK.

[Ian_C]

Get it done! No point leaving it Amar. Will definitely need coding work unless you can work out a way with jump leads to remove the old one whilst still wired up.

Mine always starts first time but didn't approx month ago which was strange. Took a second twist of the key. Then the Sunday getting it was sluggish starting, and then trying to move it back under car port after washing it wouldn't start.... and everything went blank and reset! Dash clock etc, RNSE blank! So the battery was at zero as I tried to engage starter. This was 7pm Sunday night and I had a service booked Monday 10am. I was shitting myself the battery was fucked and I wouldn't be able to get it started, but thankfully it started Monday after being left on charge using two extension leads. So I arrived at Audi and asked (begged) for discount for a new battery.

To give you an idea of the level of coding required, I drove to the dealer with no nav/stereo (code required), NOTHING working on the dash bar the fuel and temp dial - ie no speedo, rev counter, mileage, trip, no indicator 'clicks' or headlight on symbol - so I didn't think my indicators/headlights were working until I saw the reflection in the back of the car in front. Drove like <beep> too - revs died immediately as you pushed the clutch in to change gear. The drivetrain shunt was horrific if you didn't concentrate - had to keep your foot on the throttle slightly changing up. Also had the entire DIS taken up by a red oil warning. Knew the level was okay and it wasn't leaking, put in half a litre to be sure and left it idling for a while, set off for Audi and drove it steady to start with, temp didn't go above 90 so not oil pump related etc, clearly just battery related.

Dealer has coded everything back up nicely. Only thing I that doesn't seem to work is DIS current mpg, journey mpg and miles remaining on the DIS. Brimmed tank and reset trip but still no joy, so will have to google and play with Vagcom I think. Lost all my long term averages, not that I ever really looked at them.

My advice is do it asap! If you can bridge the battery during the change so the car is always connected to power, even better.

[Mr V10]

Ian, I don't think you've understood my post. Plus, the B6 doesn't require adaption after a new battery like the 4F platform does so I think you're describing something else.