Anyone replaced their 12v battery?

[Yams]

I have a 2022 SE and absolutely love the car. I have a few questions and concerns when it comes to replacing the 12 volt battery. Since my car is 3 years old today I feel like the the recharging of the 12v battery has begun to get less efficient by the High Voltage Battery (HVB). I have noticed my HVB percentage drops a few percentage points quicker than when it was new in the first few miles when I drive after not being plugged into a charger lately. The HVB recharges the 12v battery. This is just a small concern but I want to be prepared for it.
I'm aware that our cars have many powertrain parts from the BMW i3 which was the precursor to our cars and the 12v battery in those was much smaller. That being said, the BMW was a EV designed from the ground up whereas the SE was adapted from an ICE car to an EV so the 12v requirements are probably greater. I don't want a larger (heavier) 12v battery than the OEM H4 battery that came with the car but would be interested in an H3 if that would still meet the demand while parked in my garage for up to a week. With my Bimmercode I found the battery Ah is set at 55 even though the installed battery is a 50Ah. I'm wondering if a 40Ah H3 battery will be a good replacement. There is a setting for 40Ah in the ECM/PCM.
One concern I have is what's going to happen when I disconnect and then reconnect the 12v battery. Anyone replace the 12v battery themselves or experience a dead 12v? I assume the car would recover just fine from the nap w/o 12v, just have to relearn the auto UP/DOWN of the power windows and such.
There are several batteries I'm considering. FCPEuro sells an H3 40Ah BMW battery (61217635788) with a lifetime replacement warranty but I'm not sure they'd honor that since it's not the OEM size. Costco sells a high quality drop in replacement H4 battery from Interstate. There is a DieHard EV battery, H4 and H3 that is designed in some way for EVs? I haven't been able to find out how it's designed for EVs but it's a contender. Also, there are some lightweight 12v lithium batteries from Antigravity, Dakota and others but I'd have to trust the Battery Management System (BMS) of those.
Last thing I'l say is I've had the 12V battery cable recall and cleaned out a bunch of leaves from under the hood. Bimmercode has been awesome. I had to redo the changes I made prior to my 2 year maintenance because the dealership updated the ECM firmware. Thanks Everyone.

 

[insightman]

I have a 2022 SE and absolutely love the car. I have a few questions and concerns when it comes to replacing the 12 volt battery. Since my car is 3 years old today I feel like the the recharging of the 12v battery has begun to get less efficient by the High Voltage Battery (HVB). I have noticed my HVB percentage drops a few percentage points quicker than when it was new in the first few miles when I drive after not being plugged into a charger lately. The HVB recharges the 12v battery. This is just a small concern but I want to be prepared for it.
I'm aware that our cars have many powertrain parts from the BMW i3 which was the precursor to our cars and the 12v battery in those was much smaller. That being said, the BMW was a EV designed from the ground up whereas the SE was adapted from an ICE car to an EV so the 12v requirements are probably greater. I don't want a larger (heavier) 12v battery than the OEM H4 battery that came with the car but would be interested in an H3 if that would still meet the demand while parked in my garage for up to a week. With my Bimmercode I found the battery Ah is set at 55 even though the installed battery is a 50Ah. I'm wondering if a 40Ah H3 battery will be a good replacement. There is a setting for 40Ah in the ECM/PCM.
One concern I have is what's going to happen when I disconnect and then reconnect the 12v battery. Anyone replace the 12v battery themselves or experience a dead 12v? I assume the car would recover just fine from the nap w/o 12v, just have to relearn the auto UP/DOWN of the power windows and such.
There are several batteries I'm considering. FCPEuro sells an H3 40Ah BMW battery (61217635788) with a lifetime replacement warranty but I'm not sure they'd honor that since it's not the OEM size. Costco sells a high quality drop in replacement H4 battery from Interstate. There is a DieHard EV battery, H4 and H3 that is designed in some way for EVs? I haven't been able to find out how it's designed for EVs but it's a contender. Also, there are some lightweight 12v lithium batteries from Antigravity, Dakota and others but I'd have to trust the Battery Management System (BMS) of those.
Last thing I'l say is I've had the 12V battery cable recall and cleaned out a bunch of leaves from under the hood. Bimmercode has been awesome. I had to redo the changes I made prior to my 2 year maintenance because the dealership updated the ECM firmware. Thanks Everyone.

You pose an interesting question about the reason for the difference in 12V batteries between the i3 and SE.

I've never seen the battery in my 2021 (delivered in 2020) SE, thanks for the photo. I doubt that it's taking any more power from my HV battery than it ever did. Have you had your 12V battery tested and received a negative report?

I was unhappy that Honda didn't stock the 2000-2006 Honda Insight's small OEM battery in the US and I could not find an alternative lead-acid battery that was as small and light as that OEM battery. So I sympathize with your desire to investigate switching to an H3.

However, how much weight would you save with an H3 lead-acid battery? I assume it would be smaller than the OEM battery, so would it be difficult to mount securely in the SE's battery tray?

 

[Yams]

You pose an interesting question about the reason for the difference in 12V batteries between the i3 and SE.

I've never seen the battery in my 2021 (delivered in 2020) SE, thanks for the photo. I doubt that it's taking any more power from my HV battery than it ever did. Have you had your 12V battery tested and received a negative report?

I was unhappy that Honda didn't stock the 2000-2006 Honda Insight's small OEM battery in the US and I could not find an alternative lead-acid battery that was as small and light as that OEM battery. So I sympathize with your desire to investigate switching to an H3.

However, how much weight would you save with an H3 lead-acid battery? I assume it would be smaller than the OEM battery, so would it be difficult to mount securely in the SE's battery tray?

I haven't had my 12v battery tested, just made an observation from my home to a landmark 2 miles away on less than a full battery. The percentage used to get 2 miles away on a less than 100% HVB is about ~1-2% less by the instrument cluster than when it was new. Keep in mind, I'm talking about a 3 year old lead acid battery. When I fully charge my SE I still make it to the landmark 2 miles away before the percentage ticks to 99%. I've experienced no degradation in the HVB. I'm just saying that lead acid batteries have a limited life span and it'll need to be replaced at some point. Also, I know the weight difference between an H4 and H3 battery is negligible but why top up a bigger than necessary battery. The H3 will fit the same as the H4, it's just not as long. The hight and width are the same.

 

[Rexsio]

I have a 2022 SE and absolutely love the car. I have a few questions and concerns when it comes to replacing the 12 volt battery. Since my car is 3 years old today I feel like the the recharging of the 12v battery has begun to get less efficient by the High Voltage Battery (HVB). I have noticed my HVB percentage drops a few percentage points quicker than when it was new in the first few miles when I drive after not being plugged into a charger lately. The HVB recharges the 12v battery. This is just a small concern but I want to be prepared for it.
I'm aware that our cars have many powertrain parts from the BMW i3 which was the precursor to our cars and the 12v battery in those was much smaller. That being said, the BMW was a EV designed from the ground up whereas the SE was adapted from an ICE car to an EV so the 12v requirements are probably greater. I don't want a larger (heavier) 12v battery than the OEM H4 battery that came with the car but would be interested in an H3 if that would still meet the demand while parked in my garage for up to a week. With my Bimmercode I found the battery Ah is set at 55 even though the installed battery is a 50Ah. I'm wondering if a 40Ah H3 battery will be a good replacement. There is a setting for 40Ah in the ECM/PCM.
One concern I have is what's going to happen when I disconnect and then reconnect the 12v battery. Anyone replace the 12v battery themselves or experience a dead 12v? I assume the car would recover just fine from the nap w/o 12v, just have to relearn the auto UP/DOWN of the power windows and such.
There are several batteries I'm considering. FCPEuro sells an H3 40Ah BMW battery (61217635788) with a lifetime replacement warranty but I'm not sure they'd honor that since it's not the OEM size. Costco sells a high quality drop in replacement H4 battery from Interstate. There is a DieHard EV battery, H4 and H3 that is designed in some way for EVs? I haven't been able to find out how it's designed for EVs but it's a contender. Also, there are some lightweight 12v lithium batteries from Antigravity, Dakota and others but I'd have to trust the Battery Management System (BMS) of those.
Last thing I'l say is I've had the 12V battery cable recall and cleaned out a bunch of leaves from under the hood. Bimmercode has been awesome. I had to redo the changes I made prior to my 2 year maintenance because the dealership updated the ECM firmware. Thanks Everyone.

As @ Puppethead on April 16 2022 posted is the best advice for newer owners or without knowledge how a system 12 V. Battery works

 

[Rexsio]

As owner of 2014 BMW I 3 for 7 years I was worry about my 12 v / 20 Ah battery bc many owners have an issues with .I visited BMW dealer and as precaution I purchased new battery for about $260 and for 7 month I maitinanted battery with very good charger NOCO genius 2 hook up all the time and as I decide to get 2022 SE I sold i3 with 7 years old battery which was still performing 100% and I own now BMW i3 Beatifull 12 v battery. I call a dealer where I purchase 12 v battery and they were happy to give me $ 260 back bc they have dead i3 in a shop and that point those batteries were not available anywhere bc of Covid and supply issues.But as I monitor a problem there was replacement for i3 by East Penn AUX 18 L with the same posts / size/20Ah which many owners of i3 replaced with for $130 Now I hope as SE 12 v. Batteries getting older will be there some replacements for 1/2 a price but as of today I never heard anything as they failed so far and someone try to put 40 Ah in SE I NEVER be recommended stick to 50Ah OM. As they selling them OM for $ 321.29 at Mini dealers part # 61215A67278 fits 2020-2024 for electric SE (IB1) as people try mess with different sizes will be a problem to fit them correctly as they pretty heavy as 50 Ah compared to 20Ah for I 3 only 3 times heavier .i belive as AGM battery they going to last over 5 years easy and don’t mess with DC from HV battery to DC charging system 12volt can cost more than you save with different cheap battery

 

[Rexsio]

You pose an interesting question about the reason for the difference in 12V batteries between the i3 and SE.

I've never seen the battery in my 2021 (delivered in 2020) SE, thanks for the photo. I doubt that it's taking any more power from my HV battery than it ever did. Have you had your 12V battery tested and received a negative report?

I was unhappy that Honda didn't stock the 2000-2006 Honda Insight's small OEM battery in the US and I could not find an alternative lead-acid battery that was as small and light as that OEM battery. So I sympathize with your desire to investigate switching to an H3.

However, how much weight would you save with an H3 lead-acid battery? I assume it would be smaller than the OEM battery, so would it be difficult to mount securely in the SE's battery tray?

Going to smaller 12v battery don’t make any sense as your charging 12 v battery system going to kick more often as DC charging battery doing this charging 12 v battery system all the time as you plug SE to charging station or you on a street and all a trouble a battery is not worth it As I look at a picture of a battery provide by @ Yams a terminals on battery are so close to each over you can’t get any battery to be installed in that manner bc cables will be to short and BMW is not stupid and make you to buy OM battery if fail All batteries have negative / positive terminal on the ends of battery Here you have to modify a battery cover to and a weight of battery is nonsense as you clean your junk from a car will be already lighter 10 lbs as a joke.As every thing bigger better the same with battery more juice to waist as your AC or heat run of that 50Ah battery

 

[Rexsio]

As to continuing on AGM 12 V battery reading 13 V is considered fully charged and healthy as normal range for fully charged AGM battery When not actively charging a healthy AGM 12V battery should read around 12.6-12.7 Volts As you discharge a 12 V AGM battery down to 10.58 V you’ve probably killed it It’s not really dead it’s never coming back In my 2022 SE 3 years old only 18000 miles my 12 V battery sitting for 3 days in garage is shoving 13 volts .also in my wife Subaru after 5 1/2 years I replaced AGM battery to not have any issues to be call as car is dead in shopping center

 

[Yams]

View attachment 23658 As to continuing on AGM 12 V battery reading 13 V is considered fully charged and healthy as normal range for fully charged AGM battery When not actively charging a healthy AGM 12V battery should read around 12.6-12.7 Volts As you discharge a 12 V AGM battery down to 10.58 V you’ve probably killed it It’s not really dead it’s never coming back In my 2022 SE 3 years old only 18000 miles my 12 V battery sitting in garage is shoving 13 volts

Rexsio, my 12v battery is not "killed", it's fine. One day I'll need to replace it, myself, not at the dealer. FYI, I spent years as a mechanic and don't need a lecture from you about the weight of batteries or what sizes fit, I know. Thanks for your input but you're not really helping with the question. I'm asking if anyone has replaced their 12v battery and with what.

 

[Rexsio]

Rexsio, my 12v battery is not "killed", it's fine. One day I'll need to replace it, myself, not at the dealer. FYI, I spent years as a mechanic and don't need a lecture from you about the weight of batteries or what sizes fit, I know. Thanks for your input but you're not really helping with the question. I'm asking if anyone has replaced their 12v battery and with what.

As you know AGM batteries last 5-7 years and you fare away from replacement and advice not to YOU only to less knowable owners bc not every body is working on cars as some people hook up chargers on 12 V battery on SE just to mess up charging system as they drive clunkers before And EVs is different car I’m sorry I don’t mean to heart a filling but to me is a best to replace 12 V battery with OM as a problem arise as bmw make that 12 v battery specially for SE

 

[CuriousGeorge]

I have noticed my HVB percentage drops a few percentage points quicker than when it was new in the first few miles when I drive after not being plugged into a charger lately.

Is it possible that you're getting fewer "free miles" because some of the buffer of the traction battery has been released, and it has nothing to do with the 12V battery?

 

[Rexsio]

As you know AGM batteries last 5-7 years and you fare away from replacement and advice not to YOU only to less knowable owners bc not every body is working on cars as some people hook up chargers on 12 V battery on SE just to mess up charging system as they drive clunkers before And EVs is different car I’m sorry I don’t mean to heart a filling but to me is a best to replace 12 V battery with OM as a problem arise as bmw make that 12 v battery specially for SE

As I have I 3 2014 for 7 years I was ready to replace my 12 V battery and a picture shows where was disconnect located as necessary to kill a HV battery to do a simple job to put new 12 V battery as to pay $500 to dealer and battery have to be registered if you have a tools .Who can show me disconnect of HVoltage battery on SE if we don’t know where it is don’t touch as voltage is around 400 VOLTS

 

[CuriousGeorge]

Who can show me disconnect of HVoltage battery on SE if we don’t know where it is don’t touch as voltage is around 400 VOLTS

Don't trust your life to this, but there's a small disconnect located behind the right rear access panel in the hatch. You pull it partway out, then insert the hasp of a small padlock through it to prevent it from being inadvertently closed.

https://www.reddit.com/r/MINI/comments/1f0tkzy/mini_cooper_se_f56_repair/

(As I was washing my SE the other day I also spotted some sort of warning label on a cable in the motor compartment, near the cowling on the left side. I didn't investigate further, but assume it is where first responders are supposed to cut to isolate the high voltage battery from everything else.)

 

[Rexsio]

Don't trust your life to this, but there's a small disconnect located behind the right rear access panel in the hatch. You pull it partway out, then insert the hasp of a small padlock through it to prevent it from being inadvertently closed.

(As I was washing my SE the other day I also spotted some sort of warning label on a cable in the motor compartment, near the cowling on the left side. I didn't investigate further, but assume it is where first responders are supposed to cut to isolate the high voltage battery from everything else.)

As you replay first in i3 was so simple on front in a frunk you take right cover of and with your fingers you push small plastic prong and HV battery was disconnected and you belive a first responders knows as 50 different EVs where a disconnect is located an advise is to run as fare if something happened to EV as smoking or else that brown prong on picture to flip and HV battery was is disconnected

 

[Rexsio]

As you replay first in i3 was so simple on front in a frunk you take right cover of and with your fingers you push small plastic prong and HV battery was disconnected and you belive a first responders knows as 50 different EVs where a disconnect is located an advise is to run as fare if something happened to EV as smoking or else

As I look at i3 under a back sit was big lever with big fuse as I asume to kill a battery as I’m getting older I don’t investigate SE as I did i3 and the best solution is run away from a car if something going wrong

 

[insightman]

Here's the English version of the emergency HV disconnect document for the F56 MINI Cooper SE.

Unfortunately, on page 3, the "drilled hole (4)" that you should be able to see when the HV system is disconnected is not depicted.

 

[Puppethead]

Having owned multiple MINIs and needing to replace a few batteries, my experience is they use AGM batteries and they have to be "paired" with the vehicle. I believe there are issues that can come up (errors, etc.) if one doesn't do the pairing process.

 

[ColdCase]

Having owned multiple MINIs and needing to replace a few batteries, my experience is they use AGM batteries and they have to be "paired" with the vehicle. I believe there are issues that can come up (errors, etc.) if one doesn't do the pairing process.

Perhaps the SE's Intelligent Battery System (IBS) needs to be manually reset after battery replacement. Many other cars reset their IBS automatically as the IBS relearns the new battery condition. The SE's IBS may not be that intelligent.

 

[SameGuy]

My IBS is smart enough to sneak up on me at the most inopportune moments possible.

 

[Jim In Tucson]

Back to the top…

Has anyone actually replaced their [emoji637][emoji638] volt battery? Either out of necessity or proactively?

My previous plug-in car (Volt) was very sensitive to voltage drop in the [emoji637][emoji638] V battery and would simply not start when the [emoji637][emoji638] V battery dropped below XX.X V.
Happened only once, but once was enough.

I did have a jump pack which worked flawlessly. And I now keep the jump pack in the SE, so I’m probably OK. But, I’d rather be proactive than reactive.




Sent from my iPhone using Inside EVs

 

[Rexsio]

Back to the top…

Has anyone actually replaced their [emoji637][emoji638] volt battery? Either out of necessity or proactively?

My previous plug-in car (Volt) was very sensitive to voltage drop in the [emoji637][emoji638] V battery and would simply not start when the [emoji637][emoji638] V battery dropped below XX.X V.
Happened only once, but once was enough.

I did have a jump pack which worked flawlessly. And I now keep the jump pack in the SE, so I’m probably OK. But, I’d rather be proactive than reactive.




Sent from my iPhone using Inside EVs

I will never hook up any jumping cables to 12 volt battery on SE as HV battery keep up charging SE battery through DC to DC charger to 12 volt battery constantly if you plug a car to L1 or L2 or not .You have to disconnect HV battery you can do it with trickle charger or charger for AGM battery .If you have problem with 12 volt battery on SE your charging system is malfunctioning or your battery is dead.That 12 V battery is 50 Ah which is big as my BMW I 3 with 20 A h never developed a problem in 7 years .Volt was dinosaur to compare electronics to SE After 5 miles drive in 12 F temperatures my 12 Volt battery reading on picture