MME STRANDS ME IN A BLIZZARD!!

[agoldman]

the goal is NOT to apply a load, but rather to actually warm the 12v battery, and the sensors on the terminals that are informing the charge controller that the Frunk is nice and warm and safe to charge the 12v

sounds like the basis for a Saturday Night Live skit.

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[dtbaker61]

I don't think we have any evidence that there is any temp sensing of either the frunk or the 12V battery.

There *should* be a temp sensor on or near the 12v battery wired to the charge control circuit.... any decent battery charger (for sealed batteries especially) adjusts the allowable current and end of charge voltage for temperature compensation of the voltage. Hence my educated guess is that the problems with an (unheated) 12v battery in a frozen frunk may be solved by wrapping the 12v battery and terminals where the sensors presumably are in a nice warm 12v electric blanket.

I'm just trying to guess and offer a solution... you don't have to believe me, or try it.

I have spent a LOT of time with batteries, chargers, and electric cars since about 2008... and this is my best guess for a simple and safe solution to a mystery problem that may take Ford a while to release a fix for.

 

[DaveRuns]

geeze.. this is not a potential issue. this is a serous problem. there is no way I'm taking delivery until Ford responds as to what's up. I'm not a 12 volt mechanic and I certainly don't want to get stranded over this. This is really quite upsetting. Not sure what to do now. Very disheartening. Clearly this is not a fluke.

Understood. The last thing I hate to read is "you guys should get over yourselves and be ready to accept that things are going to break with your vehicle because its a new model". In my opinion, this is the wrong approach. Especially because the company has implied a painless transition to EVs, and everything was going to be seamless, to the point where you get in the car and just go. Then of course there is the radio silence. This isn't exactly instilling a lot of confidence for folks. I think the MME is going to be an awesome car after all these issues get sorted out. I look forward to seeing how the brand progresses over the next months and years. I want competition among the manufactures, as that will only make better cars at more affordable prices.

 

[dtbaker61]

sounds like the basis for a Saturday Night Live skit.

mmmmm, I can hear Donkey now.... 'I like warm Frunks, I like'em big...'

 

[Jim Glass]

Dumb question - I didn’t know there were two batteries I was supposed to watch. Is there a light or something to show if the 12v is charging(ed)?

My car only stayed in KC for a few hours, not months

I THINK the system will warn you if the 12V battery gets low.

 

[dtbaker61]

Dumb question - I didn’t know there were two batteries I was supposed to watch. Is there a light or something to show if the 12v is charging(ed)?

My car only stayed in KC for a few hours, not months

you *shouldn't* have to keep track of two batteries. Just charge up the HV battery when it shows you are out of range, and you should be good to go.

There are two batteries in the MME; one big HighVoltage (HV) one, and one little 'buffer' 12volt battery that runs all the normal car stuff like lights, horn, stereo, door locks, etc. A lot of the 12v stuff is 'always on' and pulls a little energy from the 12v battery even when parked. The MME is *supposed* to sense when the 12v battery is running low, and charge it up with a little energy from the HV battery when needed.

Apparently, low temperatures are interfering with the internal system pulling energy from the HV to charge the 12v battery when it should. could be mis-calibrated sensors, bad programming, or faulty equipment.

My suggestion for an electric blanket wrapped around the 12v battery and terminals where I suspect the 12v battery temperature sensors are is really just a band-aid, which *might* work until Ford figures out a better fix and handles it with a software patch or Dealer recall notice to 'fix' it.

 

[Peugfan]

I don't think we have any evidence that there is any temp sensing of either the frunk or the 12V battery.

There is a sensor in the positive battery cable. Ford warns to only replace the battery cable with the proper Ford cable. I don't have the the link handy right now.

 

[carbonizedbrett]

Who wants to science this sitch?

https://www.amazon.com/BATBOT-Batbot-Wireless-Voltmeter/dp/B076MKBT6R

Edit:

This might be better: https://www.amazon.com/ANCEL-BM300-Bluetooth-Automotive-Motorcycles/dp/B07WCW49YM

 

[dtbaker61]

There is a sensor in the positive battery cable. Ford warns to only replace the battery cable with the proper Ford cable. I don't have the the link handy right now.

there ya go.....

It doesn't get super cold in Santa Fe, but it's looking like my first MME mod will be a frunkectomy to enable access to LVB, and a nice warm eBlanket for temps below freezing:

$20 - https://www.amazon.com/Electric-Blanket-Tailgating-Emergency-Stalwart-BLUE/dp/B001QJQ22O/ref=sr_1_3

 

[DaveQ]

there ya go.....

It doesn't get super cold in Santa Fe, but it's looking like my first MME mod will be a frunkectomy to enable access to LVB, and a nice warm eBlanket for temps below freezing:

$20 - https://www.amazon.com/Electric-Blanket-Tailgating-Emergency-Stalwart-BLUE/dp/B001QJQ22O/ref=sr_1_3

Great visual! - frunkectomy

 

[MattG]

While there are some creative solutions in this thread, it’s not addressing the root problem. My Subaru lives outside...spends days in sub freezing temps...and when I want to drive it, I hop in and turn the key. There‘s no reason why a similar battery in the MME can’t provide similar reliability when it has a 88.8kWh backup battery attached to it. I’m confident Ford will be able to fix this, quickly.

 

[Rafgar]

Apparently his EZ pass had interference also. Which is just completely random of all things.

I guess not seeing this until just now was a good thing since it appears to have been a joke.

My GB has been great. The problem with the EZ-Pass is the IR coating on the windshield. Just have to find the right place on the windshield to mount the EZ-Pass.

 

[eponyinIL]

So I guess my car thinks I need to stay at work! Having the same issue again. Tow truck is en route. Here is a video.

 

[eponyinIL]

 

[Radish]

There *should* be a temp sensor on or near the 12v battery wired to the charge control circuit.... any decent battery charger (for sealed batteries especially) adjusts the allowable current and end of charge voltage for temperature compensation of the voltage. Hence my educated guess is that the problems with an (unheated) 12v battery in a frozen frunk may be solved by wrapping the 12v battery and terminals where the sensors presumably are in a nice warm 12v electric blanket.

I'm just trying to guess and offer a solution... you don't have to believe me, or try it.

I have spent a LOT of time with batteries, chargers, and electric cars since about 2008... and this is my best guess for a simple and safe solution to a mystery problem that may take Ford a while to release a fix for.

interesting. Ok so let’s say you’re right and that is the issue. How would Ford go about fixing that. Would they have to replace the sensor on each?

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