On my 320D ED 2012, i got the warning light at about 4.5 years old - strange how just couple of days before i'd used it on a long run and no issues, had used sport mode a bit as needing to over take on single lanes i.e tractors etc so wanted full power to make light work of it.. Took car to the dealer and they advised battery was no good and needed a new one... very expensive but had little choice as needed it working following day or day after so just had to swallow the cost.... if my current car does it at the same time, i'm probably going to get it done by a BMW indi as will likely be cheaper... Kev
For reference, a genuine BMW 90ah AGM battery is £218.17 rrp (£185 to you guys) 2 year warranty on the batteries, just like any other part
Sorry for not getting back to 'batteries' before this evening. Has been another hectic day. Won't go into the details, but since Friday we've had a family emergency to deal with. Back to BMW's energy management and battery charging. Most of us are used to charging systems where we can charge a battery to 100% SOC (State Of Charge) and the charging will have a lot of flexibility, to more or less keep a decent battery close to 100%, until the battery performance starts to tail off with age. Winter driving make take a bit of a toll, due to extra energy demands, even normal use for some drivers may lower the SOC. BMW's Intelligent alternator control (IGR), has a completely different charging strategy. To quote BMW; "In contrast to conventional charge control, the intelligent battery control avoids a 100% charge. The charge level of the battery reaches about 70 - 80% of the maximum possible charge". IGR uses three different states of charge, IGR-Low, Medium & High, depending on the battery SOC. A more conventional charging strategy only applies when the battery is in a lower (predetermined) SOC. The energy management is designed to restrict charging to conditions like over-run, (loosely termed braking regeneration), when battery charging and when energy recuperation is possible, without using engine power. Higher voltage and/or partial alternator off-load/relief is used to maintain and restrict charging. A lot of the time the alternator is only charging to accommodate energy demands in the driving phase, nothing to charge the battery. Energy management is allowing for over-run charging, to "top up" the battery past the 75 - 80% SOC. Easy to see how we can possibly have a driving profile, where we never get past the 80% SOC mark. Winter time we may not even achieve that level of charge, too much energy consumer demand, too little driving time, not enough over-runs, to charge the battery. I find that with my typical use. In winter time, there is high energy demand, trips too short, too many starts, to keep at 80% SOC or higher. Batteries are not as efficient in cold temperatures, just make it worse for some users. The occasional use of a smart charger, like the CTEK range, can make a lot of sense. The charging time before the CTEK moves from bulk to the absorption phase, at about 80%, indicates how much we are below the BMW threshold of ~80% SOC. Peter
Interesting, but a little puzzling as to why BMW would restrict their charging regime to only 80% of battery capacity. Would this not eventually lead to loss of battery efficiency and eventually adversely affect battery life? I could understand it if the alternator charged to 80% SOC and then the regenerative braking to top up towards maximum.
Fantastic stuff Peter, thank you, so 80% is the norm & only over run or using a battery charger will take it further. As an aside I use a Ring Battery charger with a memory function which allows me to change the battery without memory loss, which is handy, anyway thank you again Peter for making this charging thing a lot easier to understand.
Personally I think 80% appears a little optimistic for topping with energy recuperation. Can’t envisage many users getting to 100% SOC. Suppose they have to allow for the best case ‘top-ups’. Peter
That’s essentially it. Even when you charge to 100% SOC, the battery runs down to ~80% under the normal IGR charging strategy. You can see how it can be quite easy to run a battery down over time, even with a battery in good condition. I have become very conscious of lifting off the throttle on run downs, to get the best use of harvesting from alternator charging. I’ve run with a voltmeter connected, to watch the voltage as the alternator cuts in. Does exactly what we expect from reading BMW’s technical blurb on the subject. Voltage increases to 14.7 - 14.8V as it boosts the charge rate. Peter
Yes Peter, just checked my SOC after not using car for a week & it showed the usual 12.3 v & 60%, after a few hours charge it usually shows around 13.2v & 90%. Would be interesting to see what state it's in after a month! Car is 4 yrs old now so maybe battery is getting a bit tired.
@Ed Cotswold Pre LCI X3 xDrive 30d M Sport 63 plate. Registered October 2013. Ex BMW management vehicle.My battery is now coming up to 5 years old. History. When I purchased the vehicle in September 2014 (approx 11 months old), within a few days it kept giving me low battery warnings. The dealer advised that it had sat in BMW waiting to be released for sale, and that the reason for the warnings was that the battery had not been charged properly. I purchased a CTEK charger and charged it for several days and after that never had a problem. It is still working fine and I regularly put the charger on for many days at a time .The dealer also advised that because of all the electrical accessories and extra options on this X3 it had been fitted with a heavy duty battery normally fitted to cars in cold weather climates such as Canada, and that if a new one was needed it would have to be a special order. In fact at the time there was no availability in the EU I am up to speed on battery life and how to look after it, but in anticipation that I will need a new one sooner rather than later, could you please quote for new one. I am lying down in the event of resuscitation being required after looking at the price. The BMW battery specifications (copied from the label) are as follows: S: 61 21 7 633 698 AW: 61 21 7 604 805 158 558-10 US 12V 105 Ah 950 A (ENG/GS) 190 RC 950 CCA (SAE)
105Ah are £239.99 rrp (£204 discounted) .They are a massive great battery and weigh a tonne We can't mail order batteries though, our courier won't take them
Yes I know they are heavy and of course big. @Cotswold BMW. So in the event of me needing one, I can order one and drive over and get if fitted? Would any coding be required as it is a like for like replacement?
Absolutely. The car will still have to be plugged in to register the new battery even being the same type. I'm in talks with UPS at the moment about being able to post batteries. I just need them to go through the MSDS
@Cotswold BMW. Thanks ed! So delivery to me would be a waste, as I do not have the appropriate kit for registration. What would be the complete cost of like for like replacement and fitting and registering it?
Hi, could anyone please educate me on the reason for registering a new battery, is it for warranty reasons?or to make sure you install the correct battery maybe? I have a smart battery charger that allows the car to keep it's memory when changing batteries, is this not sufficient?..........Found this bit of info which answers my question for me...... As far as registering batt, it has merit (neccessity is up to individual choice, read on). The AGM batt is less robust but better in retaining charge than regular lead-acid batt, it requires lower current of C/10 where C is capacity of the batt here so typical batt is like 80Amp thus charging current is around 8Amp or less; while lead-acid requires but can handle up to C/4 is most cases or 20Amp. Combination of fuel efficiency like why charge batt when you don't need it, or only do it when you are crusing on freeway not stop-go traffic etc, and limitation of batt chemsitry to tell the elctronics when it's full, unlike dry cell like NiCd drop it's voltage to tell charger to stop the charger applying current for example, lead to decision to look at the batt charging profile throughout the lifetime of AGM batt, and age is one of the biggest factor. At early age the AGM requires very little charge to stay full but as it ages it needs more cause the self-discharge gets worse. So let say you have 6-yr old car, the car is never told through registration how old is batt, it has to assume the batt is as old as the car. The charging profile for 6 year old AGM may require C/7 of charge current or less to stay full most of the time and you replace the batt with another AGM batt (the new batt really neds only C/10) then you are overcharging and shorten the life of that new AGM battt. Let say you replace the batt with regular lead-acid which requires maybe C/5 to C/4 charge current then your car will always under-charge it. The question would be if batt is $200 and you'll get 4 years instad of 6 do you need batt to be registered at an extra $200 or just go ahead buy a new one again next time, it's anybody call.
wow that's a great price!!! a sytner dealership charged me total of £630... for 320D ED 2012 - it needed batter, registering and re-programming (no idea why).. I will bear you in mind if my current car needs one Bit of a trek for me but would save me alot of money i reckon.. Kev