[asolare]

Does anyone know how much BMW dealers charge (with labor) to replace the 48v mild hybrid lithium battery when they eventually fail in the m440i vehicles? I ask because I see several owners of 2019 Cayennes with 48 volt lithium batteries that have already needed replacment complaining on a Porsche forum that their dealers charged them an incomprehensible $4000 to replace them (more than half of which was for labor).

[SaltyPickle]

I would love to know this as well.

[cr2000]

Originally Posted by asolare

Does anyone know how much BMW dealers charge (with labor) to replace the 48v mild hybrid lithium battery when they eventually fail in the m440i vehicles? I ask because I see several owners of 2019 Cayennes with 48 volt lithium batteries that have already needed replacment complaining on a Porsche forum that their dealers charged them an incomprehensible $4000 to replace them (more than half of which was for labor).

The battery cost is just under $2k:

https://www.bmwpartspros.com/oem-par...IFJlc3VsdHM%3D

I can't imagine that I would ever pay $2k labor cost on top of that to change it out. Unless the dealer has some magic fairy dust that has to be sprinkled during the swap... I'm sure when your battery is ready for replacement there will be a DIY Youtube.

Oh, the 48v batteries are also warrantied against "defects and workmanship" for 8yr/80k miles, so that would seem to indicate a decent life expectancy.

[asolare]

Originally Posted by cr2000

The battery cost is just under $2k:

https://www.bmwpartspros.com/oem-par...IFJlc3VsdHM%3D

I can't imagine that I would ever pay $2k labor cost on top of that to change it out. Unless the dealer has some magic fairy dust that has to be sprinkled during the swap... I'm sure when your battery is ready for replacement there will be a DIY Youtube.

Oh, the 48v batteries are also warrantied against "defects and workmanship" for 8yr/80k miles, so that would seem to indicate a decent life expectancy.

Somehow the people complaining about getting charged $4000 with labor to replace them on Cayennes weren't still covered by any guaranty even though they had 2019 vehicles. The dealers also claimed some reason for large labor charges. They said much more was involved than just attaching a new battery, at least on the Cayenne.

[asolare]

One thing for sure. If you do have one of the vehicles with the 48v lithium batteries it sure makes sense to hook the vehicle up to a trickle charger whenver you have any extended period where the vehicle isn't being used to protect the battery. At those prices it makes sense to do anything possible to exend the life of that battery.

[asolare]

Originally Posted by asolare

Somehow the people complaining about getting charged $4000 with labor to replace them on Cayennes weren't still covered by any guaranty even though they had 2019 vehicles. The dealers also claimed some reason for large labor charges. They said much more was involved than just attaching a new battery, at least on the Cayenne.

Interestingly, while Porsche used a 48 volt lithium battery for the 2019-2021 model years, they switched to using an AGM battery instead starting in 2022. The 2019 to current Cayennes are the same genertion of that vehicle and there were no major changes to it during that time period. I think that shows the use of these super expensive lithium batteries aren't necessary other than to save some weight. I don't know whether an AGM can simply be substituted into cars that came with a lithium battery as a replacement without also making changes in coding and parts such as a harness and/or module.

[B58-M340iX]

Originally Posted by asolare

One thing for sure. If you do have one of the vehicles with the 48v lithium batteries it sure makes sense to hook the vehicle up to a trickle charger whenver you have any extended period where the vehicle isn't being used to protect the battery. At those prices it makes sense to do anything possible to exend the life of that battery.

I don't think hooking up a trickle charger to the car charges anything other than the 12v battery in the trunk/boot. I've not seen a way to directly charge the lithium battery other than connecting a charger directly to it. I'm not sure if that is detrimental to the battery or not.

[asolare]

Originally Posted by B58-M340iX

I don't think hooking up a trickle charger to the car charges anything other than the 12v battery in the trunk/boot. I've not seen a way to directly charge the lithium battery other than connecting a charger directly to it. I'm not sure if that is detrimental to the battery or not.

I'm far from expert on this and you may be right but I do know Porsche recommends a different charger for thier vehicles with the lithium LiFePO4 batteries than the ones you'd use for regular AGM batteries. Here's an example: https://smartercharger.com/products/ctek-lithium-us

CTEK says "A Lithium battery needs to be charged with Lithium car battery chargers"

I did find this thread: https://g20.bimmerpost.com/forums/sh....php?t=1779237

[larrylam646]

Originally Posted by B58-M340iX

I've not seen a way to directly charge the lithium battery other than connecting a charger directly to it.

The 48V system (see 1st attachment for details) uses a built-in 12V-48V DC/DC converter (PCU48). The PCU48 is used to convert 48V (from the 48V lithium battery) to 12V, when needed and presumably (since I have not yet found a reference other than the wiring schematic suggesting the PCU48 is a bi-directional 12V/48V converter) to convert 12V from the 12V AGM battery (or external 12V charger) to 48V when needed.

Assuming the 48V lithium battery is charged in the same manner as the auxiliary 12V lithium battery (if equipped; see 2nd attachment for details), I would suggest the 48V lithium battery will be charged (using the PCU48) in the same manner. So I recommend using a 12V AGM battery charger (assuming your main 12V battery is AGM) connected to the charging terminals in the engine compartment.

Please note the 48V battery is disconnected for safety reasons with the (engine) hood open so close the hood when charging the 48V battery.

[sjb993]

Here’s some information which is relevant. It has appeared in other posts, but just in case you haven’t seen it before.

[14Down]

Please refer to the SIB provided by sjb993.

This is an updated version of a bulletin provided in 2021, both of which explicitly state that the 48V battery will not charge with the hood closed.

[sjb993]

Originally Posted by 14Down

Please refer to the SIB provided by sjb993.

This is an updated version of a bulletin provided in 2021, both of which explicitly state that the 48V battery will not charge with the hood closed.

For me, one of the most significant things in the SIB is that a charger with >20A output should (must?) be used.

[B58-M340iX]

I've always charged my 12v battery with the hood open - now I need to test it out and see if I can get the 48v to charge with the hood open and leave it there overnight and see how it does.

[zazzau]

Originally Posted by asolare

One thing for sure. If you do have one of the vehicles with the 48v lithium batteries it sure makes sense to hook the vehicle up to a trickle charger whenver you have any extended period where the vehicle isn't being used to protect the battery. At those prices it makes sense to do anything possible to exend the life of that battery.

External charging of the vehicle uses the 12v jump start terminal in the engine compartment — primarily for charging the 12-volt battery. External charging only happens when the hood is open: with the latch open, the trickle charge juices up the 12v battery.

[gunnergahr]

Originally Posted by cr2000

The battery cost is just under $2k:

https://www.bmwpartspros.com/oem-par...IFJlc3VsdHM%3D

I can't imagine that I would ever pay $2k labor cost on top of that to change it out. Unless the dealer has some magic fairy dust that has to be sprinkled during the swap... I'm sure when your battery is ready for replacement there will be a DIY Youtube.

Oh, the 48v batteries are also warrantied against "defects and workmanship" for 8yr/80k miles, so that would seem to indicate a decent life expectancy.

Where does BMW state that warranty? I must have missed that

[asolare]

Originally Posted by gunnergahr

Where does BMW state that warranty? I must have missed that

There is quite a bit of discussion on a Porsche forum about 2019 Cayennes that have needed an enormously expensive ($3000+) replacement of their 48v lithium batteries. At first Porsche took the stasnce that once the 3 year warranty period was over you were SOL and had to replace them on your own dime. More recently, some owners have claimed (and posted copies of their service receipts as proof) that at least in some states the dealers were forced to replace them under warranty becuse they are considered part of the emissions system and the emissions system has to be warranteed for eight years. I have no first hand knowledge and am just repeating what I've read from the posts of many others on that forum.