Dead 12v battery before taking ownership of New 2023 Mach E and effect on HV battery life?

[andy12171]

Hey guys so I'm close to taking possession of a 2023 Mach E extended range up here in Canada, but just the other day when I went to see the car the ford dealership said the 12v battery was completely dead when they inspected the car, and that they were currently trickle charging it.

From every source I've seen online I see that the HV battery is supposed to top up the 12v when it gets too low, and the only time when the 12v is left to die is when the HV is also critically low or dead. This being a 2023 model and it having sat through the coldest of the Canadian winter season out at the dealership (periods of lower than -30c temps), should I worry about the time the HV lithium ion traction battery may or may not have sat completely dead, reducing its health despite this being a new car? Unfortunate that it seems even an ODB reader cannot get an accurate read on the battery health, so it wouldn't be easy to check the % health before taking ownership.

This is my first car purchase and I'm just looking for some knowledgeable reassurance. Thanks.

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[McLotus]

The 12V battery is not charged by the HV battery when the car is sitting idle. IMO it would be a good idea, but as far as I know this is the norm for most all EVs in the market.
I would not be worried about the HV state based on the 12V battery.
BTW: I am in Norway. Winters are on the same level as you experience. We have LOADS of EVs on our roads. Been driving my 23' GT for a full winter season. It performs very well indeed, also when temperatures are dropping below -20C. Range is of course effected, but as a car it works great!

 

[EMachE]

Hey guys so I'm close to taking possession of a 2023 Mach E extended range up here in Canada, but just the other day when I went to see the car the ford dealership said the 12v battery was completely dead when they inspected the car, and that they were currently trickle charging it.

From every source I've seen online I see that the HV battery is supposed to top up the 12v when it gets too low, and the only time when the 12v is left to die is when the HV is also critically low or dead. This being a 2023 model and it having sat through the coldest of the Canadian winter season out at the dealership (periods of lower than -30c temps), should I worry about the time the HV lithium ion traction battery may or may not have sat completely dead, reducing its health despite this being a new car? Unfortunate that it seems even an ODB reader cannot get an accurate read on the battery health, so it wouldn't be easy to check the % health before taking ownership.

This is my first car purchase and I'm just looking for some knowledgeable reassurance. Thanks.

My 12 v battery was dead as well and after charging I’m still using it after 3 years of ownership

 

[4sallypat]

12V battery is under new car warranty so I wouldn't worry.

When you get it, drive it alot. Driving it will recharge the 12V.

It won't recharge when its not being driven...

 

[grein002]

My only concern would be that the battery could have sulfated. Sure, it's under warranty, but if it strands you somewhere, it will still suck.

 

[macchiaz-o]

The 12V battery is not charged by the HV battery when the car is sitting idle.

It won't recharge when its not being driven...

I left my vehicle in an airport parking lot for over a week. When the LVB level fell below 40% or so, the vehicle began refilling it from the HVB. So I think the LVB is maintained while the car is parked, but perhaps only if the HVB is itself at some minimum required fill level.

 

[CameraCarl]

When I bought my 2018 Edge it had a bad cell within the 12V battery. I didn't find out until the car left me stranded while camping 50 miles from the nearest Ford dealer. I was only gone for four days but the battery was so dead that the power door locks would not open. A tow truck driver jump started the car and I took it to the nearest dealership. They could not determine why the battery had died. It was only when I got home to the selling dealership that they diagnosed the dead cell and replaced the battery. Sorry for the long story, but if it were my car, I would strongly ask the dealership to put a new battery in the car. No sense in taking chances with your very first new car, and a rather expensive one at that.

 

[Motomax]

Try to Get them to replace the 12v battery. Draining this type of battery has detrimental effect on battery health.

 

[johnnycombo]

Hey guys so I'm close to taking possession of a 2023 Mach E extended range up here in Canada, but just the other day when I went to see the car the ford dealership said the 12v battery was completely dead when they inspected the car, and that they were currently trickle charging it.

From every source I've seen online I see that the HV battery is supposed to top up the 12v when it gets too low, and the only time when the 12v is left to die is when the HV is also critically low or dead. This being a 2023 model and it having sat through the coldest of the Canadian winter season out at the dealership (periods of lower than -30c temps), should I worry about the time the HV lithium ion traction battery may or may not have sat completely dead, reducing its health despite this being a new car? Unfortunate that it seems even an ODB reader cannot get an accurate read on the battery health, so it wouldn't be easy to check the % health before taking ownership.

This is my first car purchase and I'm just looking for some knowledgeable reassurance. Thanks.

Not an unusual thing for the Mach E, when not in use the car needs to stay plugged in. A trickle charge won't do it, I use a 15 amp/3amp trickle automatic charger and it should be good in a few hours.

 

[Jerrytball]

I’ve read sometimes it’s hard to find a replacement battery for the MME, and I was going to ask, if that’s gonna be an issue down the road and you see something like the attached picture I have here, would you buy it and if you did, how long could you leave it sitting around without it becoming a paperweight or would you put a battery maintainer on it?

 

[RickMachE]

I’ve read sometimes it’s hard to find a replacement battery for the MME, and I was going to ask, if that’s gonna be an issue down the road and you see something like the attached picture I have here, would you buy it and if you did, how long could you leave it sitting around without it becoming a paperweight or would you put a battery maintainer on it?

Buy a spare for when you might need it? That's ridiculous. It has a 3 year warranty,

 

[Jerrytball]

Buy a spare for when you might need it? That's ridiculous. It has a 3 year warranty,

Yeah, I realize there is a three-year warranty. It’s just I was watching that one girl YouTube blog. She just couldn’t find a battery anywhere even though it was under warranty and just sucks if the battery is completely dead that’s all I’m saying.

 

[RickMachE]

Stop watching Youtube.

 

[Jerrytball]

Stop watching Youtube.

Yeah, I better just stay on TikTok. There’s only like one or two people out there with an MME!

but I will be making the easy access to the positive and negative terminals tomorrow.

 

[Teslaeata]

I left my vehicle in an airport parking lot for over a week. When the LVB level fell below 40% or so, the vehicle began refilling it from the HVB. So I think the LVB is maintained while the car is parked, but perhaps only if the HVB is itself at some minimum required fill level.

Yep!

That’s how the car’s designed to work.

It’s not true to say car don’t charge 12V battery when “idle”, not driving or not charging.

If 12V battery drops to 40% charge rate, charging should begin within 48 hrs if HV charge is >15% whether idle, driving or not, or on charge or not.

If 12V charge level drops to 30% charging starts immediately.

So, no need to worry about 12V charge level and be constantly checking and panicking even if it drops to 40% or less and then unnecessarily take over management of its charging.

If I were buying a car where the battery is known to have been caused to become entirely discharged I’d be changing it.

Wouldn’t care about at whose cost because I just wouldn’t let myself be left at risk of being stranded for the minimal cost of a 12V battery which became entirely discharged previously due to a condition outside that to which the car’s designed to cope with and might be due to a defective battery which the dealer will argue was not the case………because they are the motor trade and ADR - always deny responsibility to protect their profit margin at our cost and to our risk!!

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