As a point. The discussion has focussed on traditional lead acid batteries. I think we have gel batteries in the MY10 stop/start. These are different and require a different charging regime being designed for "deep discharge". Thus caution as to which model you have.

Alex

you are approaching this subject in the right way. Yes I agree with you it should be put in technical.

The problematics with todays highly electronic cars are the fact, that the various comfort electronics put an ever higher demand onto the vehicle battery.

The other problem is that few dealers deliver new cars to customers with a fully charged battery. If that battery now falls below 49% of charge, rapid sulphation will set in and drastically shorten the useful life of the battery. It can also lead to acid stratification (High SG at the bottom of the cell and low SG at the top)

We were first confronted in 1987 with these problems, when a new model of the manufacturer I was working for at that time was launched onto the SA market. Within 2 weeks the first cars (luxury class) were stranded at the airports. It became a major headache.

We then did some investigation and found that the cars were delivered to customers with an average 20% battery charge. Upon confronting the workshop personnel who did the PDI at the dealerships we were told, "but the battery is being charged while driving". That is when we had to jump into action with a national education campaign for all dealerships. It took some time, before this message was taken to heart by all the technical staff at the dealerships.

As we go along this problem will get more of a headache. On some of the latest model cars, alternators are indeed able to charge up to 14.2V, but 14.4V gassing threshold remains.

A further aspect to cause grief in years to come is the fitment of silver calcium batteries to cars with 13.8V systems. The reason why this is going to become a problem is that a silver calcium battery requires a 14.2V charge. At 13.8V the alternator will work overtime until somthing gives...

We have over 100 documented cases, where this caused a Zener diode to blow in the alternator, which effectively put it into open voltage. A 12 V alternator in "open voltage" can produce 200V. A split second (before the fuses blow) is enough to do serious damage to computers and ECU's in such vehicle.

Lets have a civilized and intelligent forum discussion about this and I am more than willing to contribute my many years of experience. But I will refuse to take part in a discussion, where ignorance rules  With kind regards
DiscoGeorge
1998 Disco1 ES 300Tdi with twin TrueTracs
2005 Disco3 TDV6 S
And some more serious stuff

Quote:

DiscoGeorge corrected himself
So, maybe should be said that "a vehicle battery cannot be charged completely by driving around"...

I think you should have said that in the first instance

pfjths wrote:

As a point. The discussion has focussed on traditional lead acid batteries. I think we have gel batteries in the MY10 stop/start. These are different and require a different charging regime being designed for "deep discharge". Thus caution as to which model you have.

Battery's lose there memory after a while. your phone does the same, eventually the battery doesn't last as long. Same with all battery's.

Explanation finished...not interested in the physics thanks! Mine: 2012 Golf GTI Edition 35
Family's: 2009 Freelander 2 HSE TD4 Auto, Stornoway

Yorkshire - God's County

The followings:
1. Increasingly electronics that still remains on after the key is removed;
2. Intense strain/load when cranking the engine together with the load of glow plugs on diesel engines;
3. Self discharging of the lead battery (less important when the car is used daily);
combined with:
4. Short distance(s) traveled inside a city, meaning short times when the alternator is allowed to (re)charge the battery;
5. Limitations that must be imposed to alternators for the charging current of the batteries;
lead to a quicker degradation/sulphation of the batteries.
Those (mainly last two), in my oppinion, are the reasons why the car battery life is shortened.
This is more obvious for taxi cars which have many more start-ups combined with short trips, therefore less time for recharging between discharges and the alternator can't properly compensate with the progressively loss of charge.
On trucks that does many interstate/long trips this is less obvious, because the alternator has the time to charge the battery.

Hi big Dave

your comments are valuable. The idea of this discussion is not to only bombard forum members with technical mumbo jumbo and formulas, but rather to look at ways to maximize the life of batteries and to reduce the likelyhood of getting stranded.

I would also like to know how many of you have had the same battery in their cars for 7 years or longer? My personal record (ok here in SA) is 12 years on a 6V battery in a 1958 vehicle. With kind regards
DiscoGeorge
1998 Disco1 ES 300Tdi with twin TrueTracs
2005 Disco3 TDV6 S
And some more serious stuff

alex_pescaru wrote:

The followings:
1. Increasingly electronics that still remains on after the key is removed;
2. Intense strain/load when cranking the engine together with the load of glow plugs on diesel engines;
3. Self discharging of the lead battery (less important when the car is used daily);
combined with:
4. Short distance(s) traveled inside a city, meaning short times when the alternator is allowed to (re)charge the battery;
5. Limitations that must be imposed to alternators for the charging current of the batteries;
lead to a quicker degradation/sulphation of the batteries.
Those (mainly last two), in my oppinion, are the reasons why the car battery life is shortened.
This is more obvious for taxi cars which have many more start-ups combined with short trips, therefore less time for recharging between discharges and the alternator can't properly compensate with the progressively loss of charge.
On trucks that does many interstate/long trips this is less obvious, because the alternator has the time to charge the battery.

Hi Alex

points 1,4 and 5 are the main culprits  With kind regards
DiscoGeorge
1998 Disco1 ES 300Tdi with twin TrueTracs
2005 Disco3 TDV6 S
And some more serious stuff

Nick, is it possible for you to change your mind and this topic to be moved to Technical?
Because it's a technical issue as long as we stick to the topic and keep things civilized.
Eventually changing its title, if OK with DiscoGeorge, to "Why your battery doesn't fully charge" or a more generic one "Battery issues".

alex_pescaru wrote:

Nick, is it possible for you to change your mind and this topic to be moved to Technical?
Because it's a technical issue as long as we stick to the topic and keep things civilized.
Eventually changing its title, if OK with DiscoGeorge, to "Why your battery doesn't fully charge" or a more generic one "Battery issues".

Hi Nick

I would go along with "Why your battery doesn't fully charge".

We could then also later have a separate thread "Influences on Motronic by a partially charged battery" which is a very intriguing topic on its on.

 With kind regards
DiscoGeorge
1998 Disco1 ES 300Tdi with twin TrueTracs
2005 Disco3 TDV6 S
And some more serious stuff

Topic Moved for you Alex

Title Changed too Former Mod/Member, with the most post & Chicken George Arch nemesis

My Ferrari has'nt got a battery charger  2007 Freelander 2 HSE TD4 Manual with Premium Pack & Moonroof.
Stornoway Grey with Ebony Black Pleather, Clear Indicators, Body Side Mouldings etc.

Thats because its a matchbox one and on your desk  Former Mod/Member, with the most post & Chicken George Arch nemesis

1969 Triumph... 15 year old battery just been changed cos it died  Mine: 2012 Golf GTI Edition 35
Family's: 2009 Freelander 2 HSE TD4 Auto, Stornoway

Yorkshire - God's County

DiscoGeorge wrote:

The problematics with todays highly electronic cars are the fact, that the various comfort electronics put an ever higher demand onto the vehicle battery.
The other problem is that few dealers deliver new cars to customers with a fully charged battery.

I will put here a link to an old file, uploaded some time ago.
BATTERY CARE MANUAL
You will see there, in Introduction chapter, that the dealers (at least LR dealers) are bound to charge the battery from time to time.
Also, from FL2 point of view, if all works OK, the quiescent drain current will be less than 24 mA. (Appendix B)
This, at least in theory, with a fully charged 80Ah battery, like the OEM ones, will translate in over 124 days (4 months) until the battery will be fully depleted. Of course towards the end of this period the battery will not be able to start the car, but at least, hopefully, it will unlock it.