When I changed my battery I never reset the system, never had a problem. I DID however charge the new battery completely before I installed it into the car.

 

As a note here I was told the battery has 85% of service life left before needing replacement. But was also told that they like to replace at 25% of service life. It maintains 12.7 volts off of the Ctek for more then 24 hours. How they measure service life , I don't know but was told that they get that information from the OBDII port on their system. As I get my annual service in April I'll see what happens next year at this time.

 

Jagtoes....Please read post #60. Did you personally and recently check your battery's voltage disconnected from car and off of Ctek on it's own? If the dealer told you the battery is at 85% of service, how could it show 12.7 when 12.66 is the norm for a 100% service life? Let us know. Just curious. Thanks.

 

I don't guess the Ctek fixed the battery for another four years but it is possible if it was sulphated. I have been running a Ctek Multi XS 4003 and an MX25 for some years now and can say for a fact that a ceramic battery which was in my XJ8L I was going to replace for high self-discharge (in fact I bought a new Bosch S5 aka Varta) about 4 years ago spent 48 hours or so on the recovery cycle and is still working well in my XK8 today. The Bosch spent 4 years on the Ctek and just went into the XK and is working well also. A Bosch S5 I bought around the same time for the High Commander's Volvo never really performed too well and although treated the same as the other never passed muster so was recently scrapped. Just goes to show - you can always get a runt.

So, your battery is specced at 800A but the tester showed 1100A after four years of service? Well, YMMV but I would certainly be having an interesting conversation with the staff about that or be looking for another shop.

As far as Interstate and Johnson Controls go - they certainly seem to own a lot of companies and manufacture all over the world including it would seem the US and Mexico so why they would bear ship costs of that weight from Germany seems odd. Still - if yours was definitely of German manufacture I guess you just got unlucky. Hope this new one works out for you but, last word, Ctek is quality kit and if you stick to it and good quality batteries you will not go wrong.

 

Perhaps because of this?

Calibration

Periodically the BMS module will instigate a self-calibration routine. To self-calibrate, the BMS first charges the battery to its full condition. Once the battery is fully charged, the BMS will discharge the battery to approximately 75% of its full state of charge, but never lower than 12.2 V. The time taken to complete this part of the routine is dependent on the electrical load on the vehicle and the length of time the vehicle is used.

When the second part of the routine has been successfully completed, the BMS will return the battery to its optimum level of charge. The optimum level of charge will be between 12.6 V and 15 V, depending on battery condition, temperature and electrical loading. This process is run approximately twice a year.

If the vehicle is only driven for short periods the self-calibration and charging process could take a number of days to complete.

 

They did not correlate the service life to any specific voltage. Before I went to my service appointment the car had been on the Ctek for a few weeks. The step 7 maintain charge on my Ctek is 13.7 volts. Driving the car on it's 90 mile trip to the dealer the voltage varies between 13.4 to 12.7 on the road. The battery check was done with the voltage in this range. Now after driving the car back home and pulling into the garage I plugged in my volt meter and it was 13.2 volts . The next day after not being on the Ctek it was 12.7. 85% of service life doesn't mean 85% of 12.6 volts. Also my volt meter only goes to 1 decimal place.

 

A battery specified as having an 800A starting capability, but which a tester shows has an 1100A capability? Seems a bit odd, to say the least.

May I suggest a possible explanation - and I will be happy for someone much better informed than me to correct me if I am wrong!

Modern electronic testers do not actually discharge the battery. They measure the internal impedance with a small AC current / using a 'Wheastone bridge' technique (depending whose write-up you believe) and having determined the internal impedance (an indication of the degree of sulphation and other deterioration) then calculate what proportion of the original, specified starting current capability the battery is still able to provide.

That is why one of the bits of information you have to feed into the tester is the originally specified starting current capability, as declared by the manufacturer and stated on the battery. If this data is not entered correctly into the tester, the result shown by the tester will not be correct. This may be what happened on this occasion.

 

Hi Dave

I purchased it at Advanced, H8AGM, manufactured by Johnson in Germany but is the same spec as every other battery like it that I looked at marketed under other names.

So far so good here, thank you!

 

He entered 850. There were multiple parameters including current battery temp.

 

 

Fair enough! So it remains a mystery.

Do you happen to know what technology the battery tester uses?

 

Midtronics GR8

Diagnostic Battery Charger for North American Cars ? Midtronics GR8

Also as an update, the new battery may have fixed the TSD backlight issue I had before BUT now I have a recline problem with both front seats. Not sure why, never had that problem before. Go figure.

 

So about about a week has passed since I took the car out, been on the Ctek with doors double locked. Drove for about an hour and the Ctek status indicator was flashing yellow when I came home. Plugged it in and it is now going through the standard laborious one step at a time.

Would this be an indication of anything out of spec?

 

Buy another ctek (different model) on Amazon and keep it for the warranty period. If it does the same thing, you can return it and you've eliminated the ctek itself.

 

 

So what should the alternator voltage be?

I’ll add that this is nothing out of the ordinary. The Ctek did the same thing with the previous battery for the last 3+ years. But Inwould think with a new battery it should not do this. Also previous drives with this new battery the indicator still flashed green so this is the first time it dropped to yellow.

 

Just an FYI my 4.3 Ctek goes through the 7 step process every time I drive in and park the car and plug in the unit. Did it since day one and I understand it is normal operation.

 

I would look for 14.4V. If much lower, that might be contributing to the 12V battery's short service life. Also see what it is as the engine speed revs up to 2,500 - 3,000 RPM.

I would also measure the quiescent current draw when the car is IG-OFF and locked. It is supposed to be less than 0.035A (35 milliamps) after more than 15 minutes has elapsed after the car was locked. If much more, that parasitic draw is taking some power from your battery charger which therefore cannot maintain the 12V battery charge to the extent expected by the charger.

 

14 volts is the spec on the alternator output. I typically see 14.2 on my Torque app.

 

Once a battery is on the out, a CTEK is not going to make it new again.