[breslaw]

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I am going to store the x5 45e in my garage for 6 months. I need to find out if I leave the high-voltage battery plugged in or plugged out. I can’t find anything in the manuals covering this situation.

[nZtiZia]

Originally Posted by breslaw

I am going to store the x5 45e in my garage for 6 months. I need to find out if I leave the high-voltage battery plugged in or plugged out. I can't find anything in the manuals covering this situation.

is there anyone who can check on it? the manual only addresses up to 3 months. still, it's safer to leave it plugged in as the "buffer" prevents 100% charge of the full 24kWh battery:
"100%" charge in U.S. is only 71% capacity
"100%" charge in EU is only 90% capacity

thermal events more readily occur when lithium batteries go below critical voltage.

[breslaw]

I read that also. No one is in the area to deal with the car. Charger says it turns off after the battery is full but I still can’t get a consistent answer from BMW.

[nZtiZia]

Originally Posted by breslaw

Charger says it turns off after the battery is full but I still can't get a consistent answer from BMW.

i read on another thread you have a BMW 120V 1.5A charger that's "50% faster". umm that doesn't makes sense as the included one is 120V 10A which still takes ~15h to fully charge from empty. did you mean 1.5kW?

i don't know your EVSE's logic, but my JuiceBox EVSE senses when the battery discharges and requires a top up, all while plugged in with no input from me.

what you can test do to test if yours "wakes up" is to run a preconditioning session when the battery is already 100% charged. preconditioning will deplete the battery a bit. hopefully your EVSE senses this then begins to charge battery. if it does, then I recommend setting a preconditioning time for one day a week while you're away.

[breslaw]

Sorry it’s 15A. Charged from empty to full in 12.5 hours.

[breslaw]

Preconditioning sound like a good idea although the car is new and I have never done that. Don’t really know much about it.

[nZtiZia]

Originally Posted by breslaw

Sorry it's 15A. Charged from empty to full in 12.5 hours.

run the test procedure above. while plugged in, if your EVSE senses the HV battery isn't fully charged (such as during a preconditioning session) then you can be rest assured your battery won't go critical while away. too bad you can't control the BMW EVSE remotely

[Silver64]

Originally Posted by breslaw

Preconditioning sound like a good idea although the car is new and I have never done that. Don’t really know much about it.

It’s simple to do from the MyBMW app, one of my favorite features so far!

[nZtiZia]

Originally Posted by Silver64

It's simple to do from the MyBMW app, one of my favorite features so far!

same. i use it every day (scheduled)!

[jad03060]

The vehicle controls when the EVSE applies power to it, unlike say a cellphone where power is attached constantly which can mess up a battery if it's left on constantly for extended periods of time.

The EVSE sends out a signal indicating how many amps are available, and an interlock. That interlock goes into the vehicle and goes through a voltage divider and when the vehicle decides it wants acv applied, it controls that line and the EVSE (supposed to) applies acv power. The interlock also goes through a switch on the release of the J1772 plug, that shuts power off so it's actually off before you can remove the plug. If the vehicle was charging at the time, being able to remove it while power is flowing could cause the connection to arc, which is avoided with that interlock scheme.

The HVB has a slow self-discharge rate, but there are things that are 'on' all of the time. Those run off of the 12vdc system, and that battery may have issues if the vehicle isn't used frequently.

I think that when the thing is actively charging, it's also charging the 12vdc battery. To ensure that happens on a regular basis, I might consider setting a recurring departure time (say once a week on repeat). That should help keep the 12vdc battery up as well. If the vehicle is locked, that would have the alarm on, which again, doesn't draw all that much power, but over time, it could be an issue.

There is logic in the vehicle that will put some bits into off mode versus sleep if the vehicle isn't used often enough that is designed to help minimize the load on the 12vdc system.

I'd check with the service manager, or call BMW directly for guidance on storage for longer than the 3-months the manual discusses.

[ksavostin]

Idk what is correct but mine 45e is staying in garage plugged in since October 2021.

[LarsOtium]

Originally Posted by breslaw

I am going to store the x5 45e in my garage for 6 months. I need to find out if I leave the high-voltage battery plugged in or plugged out. I can’t find anything in the manuals covering this situation.

On BMW website, they say if leaving for extended time frame battery should be charged between 20 and 80 percent.

How you do that I haven’t a clue. Maybe with a smart programmable charger.


Electromobilty - Charging section on BMW website

[nZtiZia]

Originally Posted by LarsOtium

On BMW website, they say if leaving for extended time frame battery should be charged between 20 and 80 percent.

How you do that I haven't a clue. Maybe with a smart programmable charger.

20-80% of its full 24kWh capacity. standard lithium battery care

U.S. based 45e use only 17.1kWh. at 100% charge, it's only at 71% capacity, so no need to do anything special.
EU based 45e use 21.6kWh which is 90% capacity when fully charged. 80% capacity would be 19.3kWh so one could stop when ~90% charged

[LogicalApex]

Leave the car plugged in.

The HV battery will act as a trickle charger for the 12v and keep itself topped off. Covered in the manual on my 530e and I am certain it is identical in yours.

[LarsOtium]

Originally Posted by LogicalApex

Leave the car plugged in.

The HV battery will act as a trickle charger for the 12v and keep itself topped off. Covered in the manual on my 530e and I am certain it is identical in yours.

Attachment 2796976

Thanks for this.

What is amazing is the amount of disinformation EVEN from BMW.

When I picked up my 45e at Performance Center I asked about trickle charger for 12 volt and my delivery specialist said using one when car sits was a good idea.

I mention this not to knock BMW delivery specialist, but rather to suggest how darn complicated the whole electrical system is in the PHEV.

[LogicalApex]

Originally Posted by LarsOtium

Thanks for this.

What is amazing is the amount of disinformation EVEN from BMW.

When I picked up my 45e at Performance Center I asked about trickle charger for 12 volt and my delivery specialist said using one when car sits was a good idea.

I mention this not to knock BMW delivery specialist, but rather to suggest how darn complicated the whole electrical system is in the PHEV.

I will admit I'm new to the brand, but I had a pretty piss poor introduction with the whole iDrive 7 lite thing that happened to me on MY2020.

I've learned, in a very harsh way, that BMW really doesn't care to do a good job educating their employees or us owners on how their technology or our cars work all that much.

I won't rant too much as I've done it enough that I'm probably sounding super bitter about it all -- I am pretty bitter about it.

At least in this aspect, the PHEV is a much easier car to store for extended periods. The pressurized fuel tank should keep fuel fresh for at least a year and the HV topping off the 12v really allows a "plug it in and forget it" storage reality. Which is nice.

[breslaw]

The X5 45e manual has the same section. No trickle charger required for 12 volt battery. But it discusses max period of 3 months. I just wanted to verify that it should remain plugged in for 6 months. I can't find anything on this topic. And the dealer doesn't know, in fact they said I should plug it out.

[LogicalApex]

Originally Posted by breslaw

The X5 45e manual has the same section. No trickle charger required for 12 volt battery. But it discusses max period of 3 months. I just wanted to verify that it should remain plugged in for 6 months. I can't find anything on this topic. And the dealer doesn't know, in fact they said I should plug it out.

You are overthinking it.

The vehicle shouldn't be left with a low state of charge. The manual isn't suggesting that you can only store it for a maximum of 3 months, but that you can't store it for more than 3 months if unplugged.

The HV battery will have a natural discharge rate, as all batteries do, so leaving it unplugged will allow that battery to eventually run to 0%. If left too long it will hit its true 0% upon which it wouldn't be possible to charge the battery ever again.

My 530xe came with a BMW Battery Log form that is supposed to be given to anyone who buys the car (the first time I presume) that has a log of what the battery charge was at various intervals when stored on the lot. It requires this check for the reason I mentioned above, but it never mentions checking for anything other than state of charge (for the reason I cited above).

[jad03060]

When I had an i3, I followed those forums. One owner spent half the year in Europe and half in the states. When he left his i3, he'd remove the 12vdc battery and leave it on a battery maintainer and pulled the HV disconnect switch. When he got home, the HV battery typically only lost a few percentage points in that six-month period. LiON batteries don't lose much, especially if you essentially disconnect any load to them. The vehicle will continue to use some power, and it does not appear that the 12vdc system is charged except when the HV system is being charged or otherwise activated (preconditioning does that)...that may take a bunch of time in-between.

[breslaw]

After all the input, some of which offered differing alternatives, I have come up with this as my 6 month recommended storing actions:
1 - Leave the HV battery plugged in
2 - No trickle charger on the 12V battery
3 - Leave the climate control for departure on once a week

As you all can see from the previous responses, no one is able to reference this circumstance in the owners manual. When speaking with BMW Service they tell me to use the trickle charger (but the manual clearly states that a trickle charger does not work on the 45e). They are unable to reconcile that difference which totally disappoints me.

[jad03060]

While you would not want to install a dumb, high current battery charger to any modern vehicle long-term, a smart battery maintainer IS acceptable. This is the page out of the 45e User's Manual that discusses it. What you're proposing probably will work as waking the vehicle up weekly will PROBABLY, but not definitely be able to keep the 12vdc battery from being degraded. I'm sure that when in the READY state, it will deal with the 12vdc battery, and think it will when preconditioning, but am not positive. A half-hour, once a week may or may not be enough, though. At least when I look at mine, it doesn't turn the EVSE back on immediately when preconditioning starts...it needs to discharge the battery a bit but in that time, the fans are working along with potentially the seat heaters, and mirrors, so you'd probably want to disable those things prior to storage.

BMW sells one made by CTEK, I have one from Bosch (but may not be the best for unattended operation as it resets to off if the line voltage is disrupted, the CTEK one does not).

[LunaTheBlue]

I’ve stored my 45e for 6 months. It’s pretty simple.

1. Charge the HV battery to 100%, owner’s manual just says to not leave it sitting for more than 3 months with less than 50% charge or it could damage / diminish the battery.

2. Attach a BMW CTEK 12V Battery Conditioner / Tender to the Starting Aid Posts under the hood (see pp 400 of the owner’s manual) and plug it in - watch to make sure it recognizes your 12V battery and starts conditioning.

3. If you are comfortable, leave the High Voltage Battery charger connected to the car’s charging port. Just know that if the battery is already charged to 100% it will not pull a charge for at least 6 months. At least mine never did. I checked 6 months of electrical reports since my charger is metered separately from my house. It didn’t charge one single time.

4. Lift the X5 off its wheels to prevent flat spotting - either with jack stands or a lift.

5. Understand that the 45e may stop responding to MyBMW app commands after roughly 30 days. I tested this twice while mine was in storage. It wouldn’t respond to the app both times unless it was unlocked with the physical key within the last 2-3 weeks. So the plan to pre-condition the car periodically may not work unless someone is able to access the car and unlock it with the physical key.

Relax and enjoy the trip that’s taking you away for a while.