Talk Morgan Forums Community Vehicle Talk (non-Morgan) Mini Cooper D F54 owners

Quite a few on here with modern Mini's it seems so thought the following worth mentioning:

Tayna and Battery Megastore (to name but two) both use the same third party cross reference from UK registration to replacement battery. They both correctly identify model, date of manufacture, engine type and model reference in this case F54 series which equates to 2 litre B47 BMW diesel in Cooper D. Unfortunately they both take you to a range of batteries of differing makes but all of the 096 series, for this model type and maybe others.

These are all AGM suitable for stop/start with correct terminals BUT shorter, 278mm, and only 70 amp hour capacity, when they should be 315mm and 80 amp hour. Given the single fixed battery clamp location they cannot be secured even if one were to accept the lower capacity!
Needless to say the correct ones are considerably more expensive

Apologies but haven't found a generic code for this type. Nothing I can find on OE either.

Richard I wonder if anyone has changed their lead acid batteries for the lithium ion equivalents, the avantage here would be less weight but alas the charging circuit would need to be changed from a standard alternator?

The “stop start” has never worked on my wife’s 2013 Mini diesel since our local tyre battery shop fitted a new battery. I took the car back and they said the new battery is suitable for stop start, they reprogrammed it on some iPad system and it still doesn’t work. Maybe it’s not the correct battery ?

Could be Craig. Wouldn't trust a local shop to fit correct battery given my experience so far just getting hold of correct one.

I know that our OE near seven year old battery was becoming increasingly reluctant to offer the stop/start function, regularly indicating it was unavailable, unless after a particularly long drive. Since fitting the new battery today just a short journey had this function working. This before I've had chance to reset ECU to new battery which I believe deletes the adaptive charge profile and resets to ex factory.

Remember Rob that hybrids and even full EV's still use lead/acid for low voltage circuits, lamps, wipers, accessories and starting of IC engine on hybrids. Whether this is cost driven I don't know, but an example I've seen shows Li-Ion costing nearly 10 times the lead/acid equivalent!

"The “stop start” has never worked on my wife’s 2013 Mini diesel "

It's funny you say that. Good ladies is an R56 Cooper S Auto. According to Mini and all the aftermarket parts sites it is stop-start and is listed as such at our local Mini dealership. I can say with confidence it has never done the dance in the 10 years we have had it. When the battery failed during the pandemic I spoke to the local Mini dealer (Harwoods) and they listed an AGM battery as it was stop start. I challenged them to take it for a drive and show me it stopping at junctions.

Anyway they wanted £400 for a battery swap and re-code. So lets just agree that an AGM battery is better (more power, less loss) if a little more expensive. I looked at the battery and went on the web sites. It was pretty obvious what model it needed. So I went to a local independent specialist and they said they would use Varta AGM and fitted the same one from the web site.

I think there is a lot of fudge in the parts and service industry.

Varta battery was OE on our F54 Mini albeit with BMW labelling. I went for the Korean brand Hankook equivalent as I've had excellent service from a large bank of them on a boat, not to mention lower price and 5 year warranty. Click below.



Realised now it's generic type 115.

Rob, I suspect you may be correct in that it seems AGM batteries may operate at higher charge rates and voltages than lead acid based systems, perhaps to allow for the extra loading of the stop start technology...? That perhaps being the case, given the extra expense of an AGM battery over a lead acid, those thinking an AGM might be a worthwhile upgrade over a lead acid might be best to just stick with lead acid...?

As an aside, both vehicles which we have and which have stop start technology do indeed operate as expected. I also suspect some vehicle battery`s suffered a lack of charge and discharge cycles during lockdown, and that perhaps additionall the Baby Boomer generation may be using their cars less frequently than they used to.. myself included and which may create issues for batteries..?

These days my modern fun car with it`s original 10 year old AGM battery, like my old Morgan, lives permanently connected to to an appropriately selected CTEK charger, though I have thoughts of replacing the 10 year old AGM as a preventative maintenance measure, in that after a period of 8 days off charge the car failed to start and the battery required charging.
While it is now permanently connected to the CTEK there is no issue, however if away from home in the car for a few days or more where the car may not be driven is unlikely to be driven or connected to a charger... Hmm..?

AGM batteries are still lead/acid George. The main difference being the electrolyte acid is absorbed into a glass mat hence the abbreviation. This makes them spill free, zero maintenance and better able to cope with vibration. Compression of electrolyte onto plates also improves high current demand. There is still a cost related case for conventional wet lead/acid though.

Richard, many thanks for providing your acknowledged superior knowledge on matters electrical and much else from which I have learned a lot.

I guess my attempt was to reply to Rob`s thinking on the charge requirements of an AGM and it`s differences to that of old style lead acid batteries, for an AGM to operate efficiently.

I was quoted circa £500 to replace my 10 year old AGM battery thus I suspect any Morgan running an old style lead acid would have to investigate carefully as to the possible advantages or disadvantages which might exist, when thinking of replacing an old style lead acid battery with a similar capacity AGM battery.

I suspect if attached to an old style electrical system an AGM may not reach a fully charged state, whether that might affect it`s performance long term connected to such a system, I have no idea.

As for longevity, given my AGM would seem to be original to the car from it`s date stamp, and has lasted 10 years and circa 42k miles over that time, seems to indicate it may have spent most of it`s life in a situation of irregular use, and which might also seem to suggest that perhaps an AGM may well operate well enough in a seldom used Morgan.... again I have no idea...

However as to whether in those 10 years my AGM may have run flat or whether it lived much of the time on a float charger of some sort would seem to be anybody`s guess..?