chuckm
Posts: 6
Joined: Wed May 31, 2017 12:31 pm

intermittent 12 volt battery drain

Mon Nov 20, 2017 6:34 am

    Occasionally overnight the 12 volt battery looses all its charge, rendering the car inoperable. The last time this happened I had to have the 12 volt battery jumped. The external charger would not charge the car. I had checked to be sure all the lights were out the night before when I shut it down.

    campfamily
    Posts: 438
    Joined: Tue Apr 21, 2015 8:07 am
    Location: Southern California

    Re: intermittent 12 volt battery drain

    Mon Nov 20, 2017 6:49 am

    Lots of threads on this subject......but first question, how old is your 12V battery? If more than 3 years, it's time to replace it.
    GONE - 2015 FFE, Magnetic with leather interior, debadged & tinted
    38,500 miles (since May 2015), average 246 Wh/mile

    REPLACED WITH - 2018 Tesla Model3, LR RWD, Obsidian Black
    11,000 miles (since Nov 2018), average 235 Wh/mile

    NightHawk
    Posts: 535
    Joined: Fri Sep 26, 2014 10:20 pm
    Location: Southern CA

    Re: intermittent 12 volt battery drain

    Mon Nov 20, 2017 1:21 pm

    Yep thats a longstanding weak link of the FFE.
    I learned to use a 12v battery maintainer overnight and get a plug in 12v meter accessory to plug in the accessory port to monitor it.
    Also I got a 12v Lion battery emergency jump unit to carry in the car.
    2014 Ford Focus Electric - Oxford White, Cloth Seats (Lease ended 9/28/2017)

    triangles
    Posts: 1056
    Joined: Tue Aug 16, 2011 11:40 am
    Location: Toledo, Ohio

    Re: intermittent 12 volt battery drain

    Tue Nov 21, 2017 9:18 am

    Hate to be the bearer of bad news but I hope you are still under warranty. I consider it a design flaw that the FFE does not log when something doesn't shut down like it is supposed to. Either that or have it designed such that one module controls access to the 12V battery. Your problem is some module is not shutting off when the car turns off. Unless it is repeatable or the mechanic happens to catch it in the act of misbehaving it is impossible to troubleshoot the cause. If you just replace the battery you may be wasting money as a strong new battery may mask the problem as it may be strong enough to keep from going dead as quickly. Search my other posts for information on this problem.

    Carbuff, I respectfully disagree. My last two Motorcraft batteries lasted 9+ years. 1 died after 9 years. The other I replaced after 9 years and ended up going into my '68VW when its battery died. That motorcraft was still working at 10+ years old when I sold my VW. I speculate it's the over abundance of electronics in modern vehicles are what's killing the batteries after only a few years. Although I'll admit it also could very likely be a case of they don't make em like they used to.
    2014 Blue Candy FFE
    http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

    campfamily
    Posts: 438
    Joined: Tue Apr 21, 2015 8:07 am
    Location: Southern California

    Re: intermittent 12 volt battery drain

    Tue Nov 21, 2017 9:52 am

    triangles wrote:Hate to be the bearer of bad news but I hope you are still under warranty. I consider it a design flaw that the FFE does not log when something doesn't shut down like it is supposed to. Either that or have it designed such that one module controls access to the 12V battery. Your problem is some module is not shutting off when the car turns off. Unless it is repeatable or the mechanic happens to catch it in the act of misbehaving it is impossible to troubleshoot the cause. If you just replace the battery you may be wasting money as a strong new battery may mask the problem as it may be strong enough to keep from going dead as quickly. Search my other posts for information on this problem.

    Carbuff, I respectfully disagree. My last two Motorcraft batteries lasted 9+ years. 1 died after 9 years. The other I replaced after 9 years and ended up going into my '68VW when its battery died. That motorcraft was still working at 10+ years old when I sold my VW. I speculate it's the over abundance of electronics in modern vehicles are what's killing the batteries after only a few years. Although I'll admit it also could very likely be a case of they don't make em like they used to.
    Triangles - I believe it is the over abundance of electronics. On all of my modern cars, batteries are only lasting 3 years maximum. Notice how hard it is to get a battery with a warranty longer than that? The battery manufacturers have figured it out!! The battery in my 65 Buick lasted ten years. That battery never failed to crank the engine, even if it sat for weeks between starts. I think I hastened it's demise by allowing one of the cells to go dry. Ditto for the batteries in my f-in-law's classics. Never a problem.

    Keith
    GONE - 2015 FFE, Magnetic with leather interior, debadged & tinted
    38,500 miles (since May 2015), average 246 Wh/mile

    REPLACED WITH - 2018 Tesla Model3, LR RWD, Obsidian Black
    11,000 miles (since Nov 2018), average 235 Wh/mile

    campfamily
    Posts: 438
    Joined: Tue Apr 21, 2015 8:07 am
    Location: Southern California

    Re: intermittent 12 volt battery drain

    Tue Nov 21, 2017 12:03 pm

    Carbuff wrote:65 buick
    Carbuff - I have a 65 Buick Skylark Gran Sport Convertible. What do you have?

    Keith
    GONE - 2015 FFE, Magnetic with leather interior, debadged & tinted
    38,500 miles (since May 2015), average 246 Wh/mile

    REPLACED WITH - 2018 Tesla Model3, LR RWD, Obsidian Black
    11,000 miles (since Nov 2018), average 235 Wh/mile

    triangles
    Posts: 1056
    Joined: Tue Aug 16, 2011 11:40 am
    Location: Toledo, Ohio

    Re: intermittent 12 volt battery drain

    Tue Nov 21, 2017 12:06 pm

    Keith,
    That makes sense both my long lived Motorcrafts were on an 80's and a 2000 Ford both with minimal electronics. Since I plan to keep my FFE until it rusts out we'll see how long I can get the Motorcraft battery that Ford replaced under warranty 2 months ago to last! :lol:
    2014 Blue Candy FFE
    http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

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