Do I need to replace my 12v battery?

[Pierre44]

I woke up this morning to a dead car (Fusion 2014 Hybrid SE)

I could not open it with the key fob and could not even activate the code on the door.

Somehow it seemed like there was not enough power to do anything.

I called AAA and they jumped started it.

 

After using it for a little while I parked it again in my driveway.

I tried using it again this afternoon and same thing.

This time I jumped started it myself by connecting the 12V battery in the left side of the trunk to my other car.

 

My question:

Can someone confirm that I need to replace the 12v battery?

I read stories about replacing the big hybrid battery and I am getting scared because this would be in the 1000's dollars....

 

Thank you for any input.

Edited October 23, 2019 by Pierre44

[3clusterliver9]

Not knowing the model year of your FFH, it’s hard to say. From what I’ve read 4-5 years is a normal lifespan of the 12v battery.

[Pierre44]

It is a 2014 Fusion Hybrid SE.

So the 12V battery is what starts the car?

[mwr]

So the 12V battery is what starts the car?

No, but it's what provides the power to activate the pre-start procedure. I'm sure someone else can explain that better, but that's the gist of it. Sounds to me like you definitely need a new 12v battery.

 

Also, I'm curious if you noticed anything odd before your experience this morning, any warning that the 12v battery was about to fail.

Edited October 24, 2019 by mwr

[murphy]

The fact that the 12 volt battery has been completely dead means you need a new 12 volt battery. Wet cell lead acid batteries shed material from the plates when completely discharged. This material collects at the bottom of the cell. When it reaches the bottom of the plates it shorts out the cell.

 

The engine is started by the high voltage battery using one of the electric motors. 12 volts must be available to connect the HVB to the car.

The car does not have a traditional starter motor or an alternator. The 12 volt battery is charged by a DC to DC converter that only operates when the car is on.

 

Personally I got rid on the inappropriate wet cell battery and installed an AGM battery which is much more suitable for the application where many microprocessors are never turned off. An AGM battery costs a lot more than a wet cell battery which is probably why Ford didn't put one in the car.

 

If you drive at least 25 miles every day you shouldn't have a problem. If the car sits for a week without being driven you will have a problem. Put a 12 volt battery charger on the 12 volt battery in that case to keep it charged.

[jnissen]

Recently replaced the 12V battery in the 2013 FFH. Thanks for all the prior posters the correct battery was fairly easy to source. Seeing the old one lasted over 7 years I just put in another lead acid.

 

BTW - The only real signs it was going was some times the door locks would not correctly unlock and the radio would shutoff almost immediately after the vehicle was shutdown.

Edited April 19, 2020 by jnissen

[klatoo]

Mine is currently 7 years old..so looking forward to fixing something else.

Just replaced the cruise control and audio module on both sides of the steering wheel since the LED's went out.  Very easy fix...thank GOD someone on YT had the videos.

[2014FordFusionSE]

My 2014's battery is 6 years old. I wonder if I should replace it early without being stranded somewhere.

Any brand recommendations?

[DJ15]

How do you open the trunk if the 12v battery has gone dead? (2014 Fusion Hybrid SE)

[murphy]

Before the battery goes dead tie a small rope to the trunk emergency exit handle.  Fold down the right rear seat and tie the other end to the latch bar for the seat.

When the battery goes dead open the car using the hidden key slot, fold down the seat and yank the rope.

[MrSquash]

I'm a brand new member reacting to the post from murphy dated Oct 24/19.

 

My wife has loved driving her 2010 Fusion Hybrid in Toronto for 12 years now, and would keep it forever if not for frequent 12V battery failures and SYNC speakers that have been randomly on/off since 2016.

 

Her first 12V battery lasted over 7 years, but the five since have lasted only 3 months, 16 months, 1 month, 30 months and 1 month in that order! They have failed in both summer and winter, always with no warning whatsoever. Admittedly she averages only 2500 miles a year, but she consistently drives it every other day.  The latest battery is actually totally dead, with my trickle charger failing to get any juice back into it whatsoever.

 

These batteries have mostly been replaced free of charge by Ford under warranty. But not the same day, and the unpredictable hassle and inconvenience has been soul destroying for both of us.

 

Our local Ford dealer, the Canadian Automobile Association and an awesome independent service guy we use have all invariably said we’re stuck with the OEM BXT-67R battery. So I’m incredibly intrigued to see you indicate an AGM replacement is an option!  Could you please provide the AGM manufacturer/product# or specifications I should pursue, and whether you would expect that Ford would be prepared to install it for me. Ford is ditching sedans and doesn’t seem to know its own products very well so I’m happy to go out on a limb here and get the potential fix done elsewhere.

 

We’d be very happy to pay a significant premium to avoid the dead battery issue in future. We finally bought a compact jump starter last year, but the hood froze up a couple of months ago and therefore my wife needed roadside assistance anyways!

[mwr]

On 2/21/2022 at 8:26 AM, MrSquash said:

I'm a brand new member reacting to the post from murphy dated Oct 24/19.

 

My wife has loved driving her 2010 Fusion Hybrid in Toronto for 12 years now, and would keep it forever if not for frequent 12V battery failures and SYNC speakers that have been randomly on/off since 2016.

 

Her first 12V battery lasted over 7 years, but the five since have lasted only 3 months, 16 months, 1 month, 30 months and 1 month in that order! They have failed in both summer and winter, always with no warning whatsoever.

My non-expert opinion is that your problem is with something other than the battery. Why? Because I can't imagine that you would have received five very bad ones in a row.

Edited February 22, 2022 by mwr

[MeeLee]

Best would probably be to replace it with a 12 V lithium battery, for longevity.
Although I'm not sure if the charging circuit will work properly, as it disconnects when the battery has sufficient charge.
And Lithium batteries generally keep sufficient voltage, until the whole unit is near to empty.

 

Other than that, you can always replace the 12V battery with a 12V battery that's larger in size.
For instance, my stock 500CCA Subaru battery was replaced with a slightly larger F150 battery which had 800CCA, and as a result, also runs the electronics for longer.
The subaru is notorious for the electronics draining the battery over a time of 2 weeks.
With the F150 battery, it now can last a good 2-3 months.

 

I think similarly you'll be able to find some very affordable value batteries in Walmart stores.
Just make sure the battery dimensions will fit.

[MrSquash]

Many thanks for these ideas! 

 

In the meantime our vehicle spent 6 days of testing at the Ford dealership with the month old 67R battery and a brand new one, and the service folks concluded once again that it was a bad battery. So we have our car back and a no charge invoice. Fingers crossed!

 

I love my lithium jump starter which fits into the glovebox and takes only 2-5% of the charge to start our Hybrid on the coldest days. But I had no idea they could be used as a regular starter battery.

 

As for using a larger battery, I believe the current 390 CCA is more than ample to start a hybrid when the battery is healthy since the HVB kicks in almost instantly to assist.

[Skifast]

 For those of you having constant battery failures, check the inside of the power plug in front of the shift knob.  I found some coins in mine shorting the system. Unplug all chargers to phones that are left in the car.