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Low battery question

2021CSGTJH12

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Hey guys. I have a 2021 Mustang GT convertible. It has 7100 miles and brand new battery I got 4 weeks ago (Die hard). I usually drive short distance once or twice a day. This is the longest I’ve gone about five days since I driven this car. I tried to start and he struggled to start, but it did start.

Sidenote: because this car has an alarm and it’s very sensitive I will leave the key 2 feet from the car in my garage hanging on the wall. The car does not get locked.

(1) because of the statement I said above or that have some type of drainage since the car does not go to sleep if the key is next to it or does the car go to sleep?


(2) I assume the battery is low so “MYMODE” doesn’t show up and all the setting went back to factory color. Does this happen when battery is low?

Thanks
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ORRadtech

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I don't believe that the car will go completely to sleep if a fob is that close.
I don't know if the mymode is a given with a low battery but modern cars do very, very odd things when the battery gets low.
I think the easiest thing for you is to buy a small battery maintainer and just hook it up when the car is sitting.
We have a '12 Edge we use as a spare car. The battery doesn't go flat in five days but it's also locked with the keys far away and has far fewer electronic controls than even my '18 convertible. It lives on a maintainer and is always ready to go.
 

Postal Bob

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Leaving the car unlocked, and the key fob near the car, will drain the battery very quickly.
As an example, my car is always locked, always on a battery tender, and the key fob far away from it. If my car isn't started for 2 weeks, it goes into deep sleep mode to conserve the battery, Recently I had my car at my detail shop for storage when I was getting a new driveway put in. 4 days after dropping it off, I got the message on my FordPass app, that the car was going into deep sleep mode because the battery charge level was getting too low. When I called the shop, they said they normally keep the cars unlocked, and the key fob on the windshield. I had to tell them they can't do that as it drains the battery quickly. I told them to lock it, move the key fob away from the car, and put a charger on the battery.
 
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2021CSGTJH12

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Leaving the car unlocked, and the key fob near the car, will drain the battery very quickly.
As an example, my car is always locked, always on a battery tender, and the key fob far away from it. If my car isn't started for 2 weeks, it goes into deep sleep mode to conserve the battery, Recently I had my car at my detail shop for storage when I was getting a new driveway put in. 4 days after dropping it off, I got the message on my FordPass app, that the car was going into deep sleep mode because the battery charge level was getting too low. When I called the shop, they said they normally keep the cars unlocked, and the key fob on the windshield. I had to tell them they can't do that as it drains the battery quickly. I told them to lock it, move the key fob away from the car, and put a charger on the battery.
Wow! Thank you for this detailed response. I never knew about this. I had a 2003 Mustang GT and always kept my key on the windshield in my garage when parked. But that car has almost no computers lol. So I did the same. I am hoping there is no electrical draws I don’t know of and just my operator stupidity.

I was able to find a BATTERY VOLTAGE on my Mustang and it read 9.5!!! That’s low but I was able to start it every time.
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