So what size jump pack?

[Two Trick Ponies]

SO, from what I understand, the only thing a jump pack will do for you is get you into the frunk if your LVB dies. It can also unlock the doors after then being connected to the LVB battery via the battery access holes or frunk panel removal. It seems that the jump pack isn't meant to "charge" the dead AGM battery to the state you can drive the vehicle and you will still need to "deal" with the battery issue in some other way so, if all this is true, what size jump pack is adequate? Will 1000 Amp pack do the job? I do understand that it needs to have the over ride button/switch. Am I missing something else that this piece of equipment will do in a pinch besides charge my phone?

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[bshaw]

The car is much better at managing the 12V battery state than when the MME was first launched.
Unless you have a dud, that LVB will last 3-4 years until it needs to be replaced.

I'm not sure having a jump pack around is going to be much use at all, especially if you are carrying it in your frunk or elsewhere in the vehicle.
If you do get one, it only has to be smallest possible 12V source because it really just needs enough power to close contacts activating the HVB. Not like an ICE car where a starter motor draws a huge amount of current all at once.

 

[BMT1071]

SO, from what I understand, the only thing a jump pack will do for you is get you into the frunk if your LVB dies. It can also unlock the doors after then being connected to the LVB battery via the battery access holes or frunk panel removal. It seems that the jump pack isn't meant to "charge" the dead AGM battery to the state you can drive the vehicle and you will still need to "deal" with the battery issue in some other way so, if all this is true, what size jump pack is adequate? Will 1000 Amp pack do the job? I do understand that it needs to have the over ride button/switch. Am I missing something else that this piece of equipment will do in a pinch besides charge my phone?

You shouldn't need to charge the 12V battery to start the car. As long as the jump pack can supply enough amperage to close the contatctors the DC-DC converter should take over and you will be able to drive home/to the parts store for a new 12V. This is all theoretical. I have not actually done this.

 

[TheVirtualTim]

If the 12v gets too low, then you can use an external 12v battery to (a) open the frunk, (b) begin charging the car's 12v battery which will allow modules to start powering back up. The 12v operates the mechanism that re-engages the high-voltage battery and allows the car to continue to charge the 12v. A completely dead car can take 20 minutes before all modules are back online -- although the car is drivable (with warnings) long before that point.

1000 amp hours is a LOT (that would be a huge battery). Most 12v batteries the size of a brick to maybe the size of a motorcycle battery are something like 5-10 amp hours ... certainly less than20 amp hours.

Early on when my car had the 12v problem, I found that a 4 amp slow-charger / maintainer was _not_ enough to recharge the car, but a 10 amp normal battery charger was more than enough and the 12v battery came back to life pretty fast at that rate.

The car has a module that monitors the 12v side and if you are using the car it will use the high-voltage battery to charge the 12v battery as needed while you drive. If you are _not_ driving but leave the car plugged in, it will use the AC power to charge your car.

If you are not plugged in and also not driving (e.g. leave the car at the airport and take a trip for a few weeks) the car should drop into "deep sleep" mode by disabling a lot of modules that don't need to left powered up. But eventually you could fully drain the 12v if it was left for long enough.

I left my car unplugged and didn't drive it for 5 days and it finally sent me a message telling me to "plug in to maintain the 12v battery" (or something like that).

 

[BMT1071]

My car was parked at the Phoenix airport for three weeks last month (110+ high every day). No issues when my wife got back in town and drove it home.

 

[Mach-Lee]

These don't work on the Mach-E usually:

The lithium ones work much better to overcome the initial surge current the Mach-E has (learn how to use the manual override button otherwise they won't work either).

Get one that's powerful enough to start a diesel engine. Amp ratings are meaningless because there is no standard.

As stated, carrying this inside the car is useless because you won't be able to get to it if the 12V battery dies. Keep in a different vehicle.

Jumper cables off another running vehicle works best.

 

[HuntingPudel]

You shouldn't need to charge the 12V battery to start the car. As long as the jump pack can supply enough amperage to close the contatctors the DC-DC converter should take over and you will be able to drive home/to the parts store for a new 12V. This is all theoretical. I have not actually done this.

The issue with being able to start the car is that the jumping source needs to sustain enough amperage for enough time to do more than just close the HV contactors. That’s why a lot of the early jump pack buyers had issues when the car’s charging logic was super-bad. The packs could generate a spike enough to crank a starter for a moment, but could not perform a sustained flow of current (IIRC, many couldn’t even pop the frunk through the jumpers in the front bumper). I don’t recall which packs actually work for this function since I haven’t a real interest in a jump pack. ?‍?

 

[Two Trick Ponies]

I actually thought I would keep this in our ICE vehicle. It would be useful for that vehicle and if the wife had to come rescue me it would already be onboard.

 

[Mach-Lee]

The issue with being able to start the car is that the jumping source needs to sustain enough amperage for enough time to do more than just close the HV contactors. That’s why a lot of the early jump pack buyers had issues when the car’s charging logic was super-bad. The packs could generate a spike enough to crank a starter for a moment, but could not perform a sustained flow of current (IIRC, many couldn’t even pop the frunk through the jumpers in the front bumper). I don’t recall which packs actually work for this function since I haven’t a real interest in a jump pack. ?‍?

Yeah I think the lithium ones give you about 10 seconds of "ON" time. You'd have to press the override button and immediately run in and start the car.

 

[bshaw]

I actually thought I would keep this in our ICE vehicle. It would be useful for that vehicle and if the wife had to come rescue me it would already be onboard.

Just keep jumper cables in the ICE car. Only thing the jump pack gets you over jumper cables is if the MachE is parked in such a way that another car could not approach the front bumper with jumper cables.

 

[CHeil402]

You can open the frunk if your 12 V battery is dead using just AA batteries (you need 8 in series to get to 12 V). Those cables in the front bumper only serve to open the frunk so you have access to the battery which can then be treated like any 12 V car battery. Once you "start" the car and close the HV contactors, the DC/DC converter of the car should be able to recharge the battery.

https://www.macheforum.com/site/thr...k-release-to-store-in-bumper.4443/post-132773

 

[Maquis]

1000 amp hours is a LOT (that would be a huge battery). Most 12v batteries the size of a brick to maybe the size of a motorcycle battery are something like 5-10 amp hours ... certainly less than20 amp hours.

When he stated “1000 Amp”, I think he refers to the way older jump packs were rated in cranking amps, not amp-hours. You’re correct, 1000 A-H would be a huge battery. About 1/5 or so of a MME SR HVB!

 

[Two Trick Ponies]

Thank you because this discussion helps me understand more about my car. I've been doing a lot of research and forum reading to get schooled up. I'm an old school 1st gen. ICE Mustang owner now learning about the 1st gen. electric Mustang.

BTW, my new MME is way more fun to drive!

 

[Maquis]

BTW, my new MME is way more fun to drive!

This is one of the reasons my 65 convertible is heading to the auction block in October.

 

[Sjboyer]

This is one of the reasons my 65 convertible is heading to the auction block in October.

Bought a red 65 HIPO in 1964, white top and interior. Always regretted selling it.

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