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i4 e40 msport 19" 859M Sunset Orange, cognac vernasca, open pore oak trim
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That could be even easier than my idea. You just carry 6-8 feet of cable.

one issue could be the amperage. The jumper battery gives some 18 amps, while the 12 volt socket only 1/2

looks like I am wrong. The socket may do 10-20 amps
Be careful.

the owner's manual warns against charging the 12v battery using the cigarette lighter socket.
 

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Be careful.

the owner's manual warns against charging the 12v battery using the cigarette lighter socket.
Agree 100%. Never really a good idea in any car as the wiring between the 12v socket and the fuse panel isn't rated for very high amperage while the lugs in the "frunk"/engine bay are nice, thick, low gauge wiring rated for the higher amperage.
 

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2023 i4 m50 Portimao/Oyster
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Note that there are charging lugs that don't require opening up the battery cover if you just need a jump
The product specialist at the PC told me I can use those to jump another car, too.
 

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In the i3, it seemed like leaving the car parked for a long time would slowly run the 12V battery down... but if you unlocked the car and locked it again (even remotely via the app), it would charge it back up again from the traction battery. The i4 might be the same, or it might be even smarter now.
 

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In the i3, it seemed like leaving the car parked for a long time would slowly run the 12V battery down... but if you unlocked the car and locked it again (even remotely via the app), it would charge it back up again from the traction battery. The i4 might be the same, or it might be even smarter now.
I think recharging the 12v is not automatic. You still need to switch on the system
 

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2022 i4 eDrive40 MSport TBII
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The product specialist at the PC told me I can use those to jump another car, too.
Really? The User Manual for the TM3 specifically warns against doing that in that particular car. Is the i4's battery actually a normal full-strength car battery, and not a low-power version like on the Model 3?
 

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2023 i4 m50 Portimao/Oyster
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Really? The User Manual for the TM3 specifically warns against doing that in that particular car. Is the i4's battery actually a normal full-strength car battery, and not a low-power version like on the Model 3?
He specifically mentioned doing that. In fact, he mentioned that as the only reason for the location of the posts under the hood. They and the washer fluid are the only reasons to ever open the hood. However, I find nothing in the manual to that effect and I wouldn't be likely to do so.
 

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He specifically mentioned doing that. In fact, he mentioned that as the only reason for the location of the posts under the hood.
The other reason for the posts under the hood is so that if you let the 12V battery die, you can get your i4 started by "boosting" it like an ICE car. From what I've heard, one of those little portable boosters that doubles as a USB charger will do the job to get an EV going too.
 
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2023 i4M50 Brooklyn Grey, Red V Leather, DAPP, PAP, LaserLights, 19"
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He specifically mentioned doing that. In fact, he mentioned that as the only reason for the location of the posts under the hood. They and the washer fluid are the only reasons to ever open the hood. However, I find nothing in the manual to that effect and I wouldn't be likely to do so.
Have you looked at the battery itself? If my car ever gets here, I'd look at the CCA rating. It's possible that they use something with deeper discharge and no cranking ability, as there's nothing to "crank."
 

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The other reason for the posts under the hood is so that if you let the 12V battery die, you can get your i4 started by "boosting" it like an ICE car. From what I've heard, one of those little portable boosters that doubles as a USB charger will do the job to get an EV going too.
I don't see this noted anywhere. I'd be hesitant to do this without BMW Roadside Assistance doing it!
 

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Have you looked at the battery itself? If my car ever gets here, I'd look at the CCA rating. It's possible that they use something with deeper discharge and no cranking ability, as there's nothing to "crank."
I've looked at it, but not to that detail. I know where it is. What would I look for?
 

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2023 i4M50 Brooklyn Grey, Red V Leather, DAPP, PAP, LaserLights, 19"
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I've looked at it, but not to that detail. I know where it is. What would I look for?
The label should show CCA or cold cranking amps. Alternatively, some kind of size or group/type number that would allow reverse lookup of the specs. Gonna need replacement in a few years anyway, preferably before failure. Maybe five years is reasonable for lead/acid. Might get some idea it's an easily replaceable component or something special.
 

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The label should show CCA or cold cranking amps. Alternatively, some kind of size or group/type number that would allow reverse lookup of the specs. Gonna need replacement in a few years anyway, preferably before failure. Maybe five years is reasonable for lead/acid. Might get some idea it's an easily replaceable component or something special.
Someone who knows more than I do might be able to find that on the labels... I couldn't.
 

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Someone who knows more than I do might be able to find that on the labels... I couldn't.
Not really important until battery replacement time. If you try to jump start another (ice) car, it may or may not have the power to crank the starter. My interest is whether it's a simple home replacement or requires some kind of rare/proprietary battery. (Others have said Tesla uses a lithium battery.) I did interrogate the usual battery suspects and didn't find the I4 listed for a simple 12v replacement. Might be too new.
 

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2023 i4 m50 Portimao/Oyster
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Not really important until battery replacement time. If you try to jump start another (ice) car, it may or may not have the power to crank the starter. My interest is whether it's a simple home replacement or requires some kind of rare/proprietary battery. (Others have said Team a uses a lithium battery.) I did interrogate the usual battery suspects and didn't find the I4 listed for a simple 12v replacement. Might be too new.
It's definitely Pb (that label is easy to read!). It looks smaller than standard to me, but, again, I'm no expert. It's close to the same as an ICE, though, it seems to me.
 

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It's definitely Pb (that label is easy to read!). It looks smaller than standard to me, but, again, I'm no expert. It's close to the same as an ICE, though, it seems to me.
Good. That should keep the maintenance cost lower. When needed, I like to replace original, traditional SLA's with AGM's when available. Costs a little more, but still less than LiPo.
 

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Good. That should keep the maintenance cost lower. When needed, I like to replace original, traditional SLA's with AGM's when available. Costs a little more, but still less than LiPo.
You and your acronyms! You lost me, again! Care to expand for the ignorant?
 

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You and your acronyms! You lost me, again! Care to expand for the ignorant?
Sorry. SLA - Sealed Lead Acid; Lead plates and acid. AGM - Absorbed Glass Mat; still a form of SLA, but more durable. LiPo - short for Lithium Polymer, also, sometimes, Lithium Iron Phosphate; our drive batteries.
 
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