Member Since: 13 Jan 2009
Location: Bavaria
Posts: 136
Replacement AGM Battery and BMS reset
Sorry for another battery topic but this is supposed to be a guide for everyone thinking about replacing the original battery with an AGM type and a summary of what to bear in mind about it.
After around 3 1/2 years my battery seems to be in quite bad condition. I have a cig voltmeter which shows around 11.7V when the vehicle was parked for a while. Although it still manages to start the engine I think it was time for a new battery. While driving the voltmeter constantly showed between 14.6-14.8 V. So obviously the alternator is not able to top up the batt properly (even after it was fully charged by the dealer). Of course I also have the issue with the FBH switching off after 3 mins....
I decided to replace the old batt with a AGM type. I chose the Varta G14 95Ah AGM battery. It has been delivered yesterday but now I hesitate to install it.
The question now is can I just swap the battery? Normally a BMS reset has to be done to tell the BMS that a new battery has been installed so it can relearn its capacity, state of charge and so on.
So....
...what if I simply swap the battery? Will I still see the high voltages while driving because the BMS has no idea about the new battery and will still try to charge a nearly empty battery? 14.8V on an actually fully charged battery don't seem to be healthy over time...
...I read on the forum that the BMS has the ability to recalibrate itself over time (a few days). Can anyone confirm this with the workshop manual or by own experience? I would like to avoid seeing the dealer because he's a two hour drive away and will keep the car over night to discharge and recharge the battery and reset the BMS.
...I also own a faultmate. Can the reset be done with this gadget also?
Thank you very much for your inputs. This will also help others when the temps get low and the battery replacement high season starts
MarcLife in the slow lane
I'm in the same position as you viethson, except I've not yet received my new AGM battery. From what I've read, the AGM battery is more tolerant of rapid charging and can still provide the cranking amps from a lower state of charge. Maybe install your new battery and see how it performs, then if you think it could be better, get the BMS reset? I'm also wondering if faultmate or Autologic can reset the BMS - hopefully they can because I hate paying the main dealer an hours labour (min charge) just to do a 5 minute job!Previously:
2005 D3 2.7 TDV6 S
1984 90 2.25 Petrol CSW
1992 90 200TDi Hard Top
1995 Discovery ES 300TDi
2003 90 TD5 Truck Cab
I just slapped a new AGM battery in mine. Didn't update anything. Its been fine Mark.
2006, D3 SE Auto - gone but not forgotten.
2014 BMW 530d M Sport Tourer.
1977 Triumph Spitfire 1500
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2nd Feb 2014 10:34 am
Windowlicker
Member Since: 12 Sep 2010
Location: East Yorkshire
Posts: 580
As per Anglefire, I just bought one from Armstrong Masseys and fitted it, they didn't mention anything was required, knowing it was a D3 and what it was replacing , and I had no idea anything was required, or for that matter what a BMS actually means
I've had no issues with mine, I trickle charge through the week, every other week as it stands unused all week most weeks.
Should I have / be doing something to suit the AGM battery.?
Thanks ,
Nick Procrastination is the thief of time!!
2nd Feb 2014 11:03 am
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
I think some D3 owners above have not noticed that they are posting in the D4 section. Clearly the D3 has nothing to reset!
The formal answer according to Land Rover:
Quote:
On in service vehicles fitted with a Battery Monitoring System (BMS), the BMS module must be reset following the installation of a new battery. The BMS module reset procedure must be performed using an approved diagnostic system.
The informal answer is that it does not really seem to matter on early versions of the BMS. That may be due to how flaky the early BMS was but due to the problems experienced by many there were a number of updates to the BMS. As such it is hard to say definitively what may or may not be needed, outside of the formal advice.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 12 Sep 2010
Location: East Yorkshire
Posts: 580
oops.
Thanks Robbie , I hadn't noticed the D4 relevance.
I'll carry on as I was then
Cheers.Procrastination is the thief of time!!
2nd Feb 2014 11:23 am
viethson
Member Since: 13 Jan 2009
Location: Bavaria
Posts: 136
In the meantime I have fitted the AGM batt. It's working great also solved the FBH problem (at least for now). Charging volts are still around 14.6-14.8V as expected. I think with the cold outside temps a slightly higher voltage shouldn't do too much damage to the battery. But maybe in summer 14.8V on a full battery could be a little too much over time...on the other hand I picked up my D4 in August and have never since seen any voltage lower than 14.6V even with the original LR batt. So maybe the early BMS systems are just supposed to work like that. Have also never seen any changes to the voltage depending on engine load.Life in the slow lane
2nd Feb 2014 9:50 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
The voltage does seem a little high, even with the lower temperatures.
Does it regulate at all or is it straight to those voltages?Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 13 Jan 2009
Location: Bavaria
Posts: 136
strait between 14.6-14.8V. As mentioned I have never seen it drop below that. But maybe that was just because the old battery was never really fully charged. But since I have done some longer trips with several hours of driving time and still had that charging voltage I figured it might be unable to either charge properly or hold the charge so I replaced it with the AGM. After uninstalling the old batt I had around 12V so was nearly half full. So regarding that state of charge the 14.6V seemed to be ok. So it still makes sense to me. But of course I installed the AGM batt fully charged so question is will the BMS ever adopt to the new battery.Life in the slow lane
3rd Feb 2014 10:54 am
viethson
Member Since: 13 Jan 2009
Location: Bavaria
Posts: 136
Having left the car for around two weeks without driving my cig voltmeter showed 7.6V and of course I was unable to start the car (even the lower tailgate would not unlock). I was able to jump start the car with aux battery of my traxide system.
After the drive home (around 30min motorway) the batt now shows 11.7V and the aux batt 12.0V.
How can a brand new 95aH AGM batt plus 55aH aux batt discharge like that in just under two weeks?
And with 7.6V the battery should be quite dead and would not recover to a nearly half full charge in just 30 min Very strange.
I also discovered a plug on the BMS. Could this be an easy way to reset the BMS? Life in the slow lane
13th Feb 2014 12:40 pm
CUCO
Member Since: 27 May 2011
Location: Spain & Oleee!!!
Posts: 609
Get it checked. It must not be at this voltage after 2 weeks. Mine with a 4 years batt (standard lead land rover batt) hold voltage for many weeks without problem and start at the touch of the button turning happily.
13th Feb 2014 2:37 pm
lespes
Member Since: 17 Sep 2009
Location: Sitting Down
Posts: 2232
Found my Traxide sys did nothing noticeable in maintaining a charge in the main battery, it is designed to isolate itself from the main battery when certain paremeters of disharge are met. It can top the main battery up when resting but this sounds like you have a drain somewhere on your main battery.D4 Landmark MY16 Santorini Black THE LAST
D4 HSE MY12 Marmais Teal: Gone. Missed a lot!
Freelander 2 SD HSE MY11 Silver:Thankfully gone.
D4 HSE MY11 Silver: Gone missed !
Range Rover Sport MY06 HSE Buck Blue: Gone missed!
Discovery D2 TD5 Facelift MY Red Gone Missed!
Discovery D2 TD5 Cobalt Blue: Gone Missed!
Discovery D1 Auto Oxford Blue Not missed at all!
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Now demoted to a VW
13th Feb 2014 3:41 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
viethson wrote:
Having left the car for around two weeks without driving my cig voltmeter showed 7.6V and of course I was unable to start the car...After the drive home (around 30min motorway) the batt now shows 11.7V and the aux batt 12.0V.
How can a brand new 95aH AGM batt plus 55aH aux batt discharge like that in just under two weeks?
And with 7.6V the battery should be quite dead and would not recover to a nearly half full charge in just 30 min Very strange.
I suspect you have a parasitic drain somewhere, either a component is drawing more current than it should or the alternator has a diode fault and is leaking to earth when you are parked. The apparent recovery in 30 min will mainly be surface charge and will not have much cranking energy. You can only realistically charge a battery with a battery charger for at least overnight, the alternator will not do it.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 13 Jan 2009
Location: Bavaria
Posts: 136
Thanks for your ideas
At least the Traxide helped me to start the car when the main batt was flat.
The charge received during the 30min drive was however able to start the car the next afternoon without any further charging.
I will have the car checked for drain in the meantime.Life in the slow lane
14th Feb 2014 12:10 am
amazing
Member Since: 05 Mar 2011
Location: chengdu
Posts: 1542
my main battery packed in and the traxide second batt would not start it...not even a click.
had to use second car to charge for about 15mins before it would start.
new battery fitted u.der warrenty andots of resetting by the techIt is better to have and not need it then need and not have it.
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and of course I was unable to start the car (even the lower tailgate would not unlock). I was able to jump start the car with aux battery of my traxide system.
Very strange.
