[MyfirstBMW_X3M40i]

Originally Posted by freshxdough

You don't need to worry about anything regarding the 12v battery charge by the energy screen. Your car is charging and monitoring it properly. No need for any kind of external charger.

Thanks, I was thinking more trying to get the 48v battery full, saying that have a 100mile round trip tomorrow, most of it motorway, that should do it.

[freshxdough]

Originally Posted by MyfirstBMW_X3M40i

Thanks, I was thinking more trying to get the 48v battery full, saying that have a 100mile round trip tomorrow, most of it motorway, that should do it.

Yeah the 48v mild hybrid battery has nothing to do with adding actual range and will be charged and discharged accordingly based on vehicle needs. Your electrical system will take care of all of that.

[phytonic]

Is the 48v battery considered a "hybrid" battery and therefore has the longer warranty? Or is it only under the 4/50 coverage? Expensive to replace according to this thread!

[misterdom]

Originally Posted by murellus

Is the 48V system battery have a specified service life? Can't seem to find anything, wondering if this is a nasty cost down the road.

I've searched for this as well and haven't found anything.

[Keefy]

It simply gives you a small boast which equates to around 11bhp….and almost instant torque, with minimal lag.

[MontyB1]

As above minimal assistance and NOT a hybrid. They offer 30-50miles of charge this provides 0miles of charge but assistance in situations like stop start and rolling or adding power under acceleration.

[lfdal54]

Originally Posted by freshxdough

Yeah the 48v mild hybrid battery has nothing to do with adding actual range and will be charged and discharged accordingly based on vehicle needs. Your electrical system will take care of all of that.

Okay, I'm a little puzzled, although that's not unusual. I read that letting the 48v battery go below 18-20% was bad, typical of a Lithium Ion. In regular driving, my battery seems to be at about 20% - 1 blue blue "cell" showing in the display under driving info. After a five-hundred-mile trip this past week it's somewhere in the 2 "cell" range.

Looking at the previous posts in the thread I popped the hood, left it open, and connected my battery tender to the 12v posts in the engine bay. I left it on for about 24 hours with zero change to the battery "Cells" showing.

Does the car need to be left in any other state to charge? I left it with the doors locked and the alarm on.

[br438]

I'm fine with it, and I hate it. It is added complexity that does not add to the core reason I bought the X3 m40i.

On the highway - long downhill sections - cruising in eco pro with the ICE engine off completely = pretty cool. I love the fuel savings.

Auto-stop "aid"... nope. It's still not smooth, and it's still incredibly noticable. We have more stop signs than anything around here, and auto-stop is a soul-crusher at stop sign after stop sign... even shutting off while creeping in line for a stop sign. I hate auto-stop (with the exception of looong stoplights), and if you are going to drive aggressively, why would want the engine off - oil settling back down in to the sump... and then be on the throttle hard as soon as the car starts. so - the boost part applies - the auto-off is antithetical to the drive-it-like-a-sports-car mindset.

[freshxdough]

Originally Posted by lfdal54

Okay, I'm a little puzzled, although that's not unusual. I read that letting the 48v battery go below 18-20% was bad, typical of a Lithium Ion. In regular driving, my battery seems to be at about 20% - 1 blue blue "cell" showing in the display under driving info. After a five-hundred-mile trip this past week it's somewhere in the 2 "cell" range.

Looking at the previous posts in the thread I popped the hood, left it open, and connected my battery tender to the 12v posts in the engine bay. I left it on for about 24 hours with zero change to the battery "Cells" showing.

Does the car need to be left in any other state to charge? I left it with the doors locked and the alarm on.

The battery will charge and discharge when needed. You can’t really control it like you can an actual PHEV or BEV vehicle. Just drive it how you normally drive it. No need to try to charge the vehicle to “top up” the 48V lithium. A trickle charge is very slow so maybe it was still just keeping your 12v topped up. DC DC converter to charge the 48V may only happen when charging at a significant rate

[br438]

FYI: If it helps anyone to understand the system, my empirical evidence says that, when I drive in Sport or Sport Plus and hoon it about, the 48v battery actually gets charged quite a bit (or charged the same and not used at all). If I check after spirited driving, it is always at 4 or 5 cells represented on the display.

If I'm driving in comfort or eco pro,... it is 2 or 3 cells.... It is possible that BMW has tried to disguise the regenerative braking only in heavy braking scenarios... so driving lightly and being easy on the brakes just won't put that much back into the system. ?? It's a quirky one for sure.

[murellus]

Originally Posted by lfdal54

Okay, I'm a little puzzled, although that's not unusual. I read that letting the 48v battery go below 18-20% was bad, typical of a Lithium Ion. In regular driving, my battery seems to be at about 20% - 1 blue blue "cell" showing in the display under driving info. After a five-hundred-mile trip this past week it's somewhere in the 2 "cell" range.

Looking at the previous posts in the thread I popped the hood, left it open, and connected my battery tender to the 12v posts in the engine bay. I left it on for about 24 hours with zero change to the battery "Cells" showing.

Does the car need to be left in any other state to charge? I left it with the doors locked and the alarm on.

20% of charge may not be 20% of the scale we see, as in 0 on our indicator may still be >20% of total charge on the battery in order to preserve it.

[bouchy]

Even though having x30d LCI - as others say, 4-5 bars on display typically, 1-2 almost never. 1 bar most probably isn't correspending to 20% od capacity. There will be a minimal
("internal") charge, considering it as 0%. I love the "READY" to start feature, it does not consume any charge from the 12V "main" battery, which is important now and then (for cold starts in winter). When refuelled, then a longer drive, the diesel consumption displays lovely 5,7-6,0 l/100km (let's make it 40 MPG)... not bad for 3 litre six cylinder.

[lfdal54]

Here's why I was curious about this, I pulled a data report yesterday after I had put the battery tender on the car the day before. The tender, BMWs product, indicated a "green" light so I'm assuming it thought everything was fine.

I'd welcome some of the more astute folks helping me to analyze what I'm seeing in terms of battery charge info, and whether or not I have any issues.

[lfdal54]

Going to add this one I took a day later. I don't know what they mean by "Charging status of battery." Is that a measure of the battery's state of charge, or the percent of maximum charge the alternator/charging system is feeding to it to maintain the charge?

[johndoe1983]

I bought last sept a M440i 2021 cabriolet with 23,000 km on it.

Drove 3000km last fall for a 7.5 liter/100 km. Very impressive.

Stored the car in october and started it for the first time yesterday in my garage. The Idrive system tell me I have a battery management problem. The rear defrost is constantly flashing.

I used at first a BMW 4 amp trickle charger which gave me those problems. I bought a 15 amp charger which I connected via the post under the hood all winter long.

I unplug the 48 volt battery, let the hood open for 5 months. The 12 volt battery is indicating 12.8 volt. No way to measure the 48 volt battery since the terminals are under part of the frame.

Lots of people have the same problem as I have. No one has the right solution except one guy wrote that he had to go to the dealer to have the car re-program.

Went to the dealer and they have never seen that problem. My car is store for the next month and legally I cannot drive it since my plate are store for 6 months.

Will see what will happen on may 1st for my first ride.