12v drain when leaving L2 EVSE plugged in??

Hey guys and gals,

I had my 2014 FFE for a little over 2 weeks now and twice the 12v battery died on me. A jump was all it took but I couldn't find anything that could have caused it.

I work from home most of the week and only get to drive my FFE maybe 2-3 times a week and have an outdoor EVSE installed (Leviton EVB40). Normally, the car doesn't stay plugged in for more than 12hs without driving, but on the weekends, I was leaving it plugged in the whole time. and Sure enough, twice on Monday, the 12V was dead.

I made sure I put it in Park before turning it off (and opening the door), I checked all the internal switches and left nothing on or plugged in inside the FFE. The only "pattern" I found was that leaving the L2 plugged in after the HVB is fully charged for more than a day or so will cause the 12v to drain.

I called Ford and they said that they don't recommend leaving the car plugged in if it's already fully charged (although that was an EV Specialist on the phone, so I'm not sure how reliable that info is since nothing on the manuals say anything about not leaving it plugged in). I called Leviton and they said that other owners leave their EVs plugged in all the time and have no issues.

I saw a few posts about the 12v draining and one of them talked about a Leviton L2. Can anyone confirm whether or not they were able to leave the FFE connected to a L2 EVSE for over 24-36 hours without turning it on at all and had no issues with battery drain?

Regards,

DudeFromBrazil

Left mine plugged into a GE EVSE L2 for 2 weeks while I was on a trip - no problemw

I went out to my car one day and I could not get it to start. I checked MFM and I got a notice saying my 12 V battery was low. Yikes. I plugged in the car and after a few minutes the car was able to start and all was fine.

I saw a post and it seemed to be what happened to me which was that leaving items plugged into the USB ports seem to drain the 12 V battery. So ever since I dont leave stuff plugged into the USB ports. Something to check. Also check any other lights, etc to make sure nothing else is left on.

John

Sounds like time to visit your dealer. That doesn't seem normal. Even with something plugged into your USB port, the battery shouldn't drain in that little time (yeah, sorry if you have a laptop charger plugged into it, well that might drain the battery).

My car hasn't been plugged in for over two weeks - it is sitting at a garage. The 12V battery is perfectly fine.

I have the same issue as Dude (OP). Brand new (fleet/work) car. Drove it last Friday, returned, plugged it in, and left work. Monday morning, I unplugged the charger, but 12v battery was completely dead. Key fobs were not funtional, nothing in car was responsive in any way. Called roadside assistance, who sent a tow truck. Upon arrival, the technician jumped the 12v battery, and the car immediately "turned on", and was able to start and drive. I immediately drove to the dealership. Surprise! They could not duplicate the problem over two days at the shop.

Thanks for the post regarding leaving the car plugged in after it's fully charged. I'll try to monitor that, to see if I can isolate the cause here.

Overall, I like the car and it's design. This is our first negative, but it's a pretty big one...

This is a touch concerning for me now. I get "It's hot outside plug me in". A lot. I really wouldn't want to plug it in all the time to have it kill the battery.

Those that have had it drain the 12v are you by chance on 3.5?

I commonly leave my Focus plugged in to a L2 EVSE over the weekend and have not had a problem. I often drive on Saturday and plug in in the afternoon, using the car again on Monday morning. I have also had the car plugged in for over 48 hours with no ill effects. I am leasing, so I don't worry about battery capacity issues.

Oilman

johnny said:

I saw a post and it seemed to be what happened to me which was that leaving items plugged into the USB ports seem to drain the 12 V battery. So ever since I dont leave stuff plugged into the USB ports.

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Leaving a phone plugged into the USB would have no affect on the battery because the current draw is minimal. Unless plugging something into the USB when the car is off somehow keeps relays open, a 12 volt car battery would have to have a phone attached for several weeks for it to even begin to draw down the battery. A search of the FFE manual shows no caution against leaving your USB devise plugged in when the car is off. (Although I did find that you should NOT adjust your device while driving because you may injure yourself or others.)

az erik said:

I get "It's hot outside plug me in". A lot. I really wouldn't want to plug it in all the time to have it kill the battery.

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Ah, this is the dilemma. The Captain Kirk "Kobayashi Maru scenario" of the electric vehicle: It's not good to let your battery stay hot, but it's not good to keep it fully charged. What to do. What to do.

I would hazard a guess that it is less harmful to your battery to keep it plugged in during especially hot times. Heat will kill a lithium battery faster than keeping it on charge. And if you can't plug it in (or even get to the car), one of our forum members starts the car to cool down the battery. Apparently this works. (If you have the luxury of wasting a few kW's.)

unplugged said:

Leaving a phone plugged into the USB would have no affect on the battery because the current draw is minimal. Unless plugging something into the USB when the car is off somehow keeps relays open, a 12 volt car battery would have to have a phone attached for several weeks for it to even begin to draw down the battery. A search of the FFE manual shows no caution against leaving your USB devise plugged in when the car is off. (Although I did find that you should NOT adjust your device while driving because you may injure yourself or others.)

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Perhaps a phone that, once charged, stops drawing much power, wouldn't kill your battery very quickly, but a car battery can be drained faster than one might think. And, they don't necessarily need to be fully drained to cause problems.

The typical small car battery energy capacity is 50 amp-hours (Ah), more or less. So, if you leave a device connected that continually draws the maximum standard USB hub port power, which is 500 milliamps (mA), a simple calculation tells us how long until the battery is completely drained:

50Ah / 0.500A = 100 hours = ~4 days

Even a half-current device would kill a 50Ah battery in just over a week:

50Ah / 0.250A = 200 hours = ~8 days

Coconut Joe the battery man! I checked out my battery and see that it is not charging unless you are driving a bad thing for a lead acid battery. The voltage for a lead acid for a charge is 14 to 15.5 volts at 65F more or less, as temps go up voltage goes down. I found a 400ma draw on battery if left plugged in lets say 4days it would more then likely kill the battery. After a battery had been drained slowly for a long time the plates in the battery get calcifaied/carroded and needs( EQUAlization). The battery voltage at 15volts will knock crud off plates but that crud is some of your plate's and the first time you killed your battery drop its/the battery Life$$$ by 1/2 .The EQUALIZATION part of the charge is about 15minute then trickle charge for 12 hours battery temp 100fmax and voltage 15.5 max trickle around 14volt let battery cool/ unplug battery time to time from charger. Even when I'M pugged in my 12volt battery never charges, I see that is a Big design problem for Ford.

Just reading all of the posts on battery issues on the FFE, along with my failing battery, I am of the opinion that:
1. The battery in service on the FFE and the Hybrids is suspect;
2. The trickle charge when plugged in is suspect (mine is only reaching 12.66v which is low for 12v charging), the amount of time the trickle is on versus the time the HVB charges may be insufficient over a number of days to keep the battery at its peak;
3. whether there is a problem with charging from the HVB;

All in all, I am going for a battery replacement and a verification of charging voltages both in operation from the HVB and during plug in.

As for leaving the vehicle plugged in, there should be zero negatives from maintaining AC to the vehicle's systems. Remember the smart safety switch we refer to as a level 2 charger only energizes the cord to the FFE when the car requests it. In hot weather, the car will request a connection to run the battery fans. It also requests connection to trickle charge the accessory battery. Of course it requests a connection to charge the HVB. It requests connection to remote start your car for go times. It is expected to be plugged in when not in use. A properly functioning car should not have any trouble being connected to the EVSE. Once charging is complete the EVSE disconnects. When mine began kicking on more than normal I became concerned.

Good luck to all of us fighting the only negative I have to report on my gasless wonder...

LJ

I got home yesterday at 5 PM and plugged in the eFord. Fully charged, I unplugged it at 7 PM to get the Jeep out for my neighbor. The eFord stayed off the charger overnight. This morning about 5:30 AM, it was dead. No power at all. No lights. Had to jump start the electric car from the pickup. It wasn’t like the 12V low voltage battery was dead because the eFord lit up about the time I touched the jumper cables to the battery. More like a relay somewhere was sticking. It drove to work like nothing happened.
Had you ever had that happen? Does it sound like that issue with the 12V battery not charging that a couple of folks had?

Update 8/19/14
Had this issue a couple of times. When unplugged, the car would not 'start' or respond to the key fob. Monday I drove it to work after jumpstarting from my pickup. At work I plugged in to 120V A/C and put the 12V charger on the battery. After 2 hours I went out to take the 12V charger off and measure the voltage. With the 120V A/C charger plugged in I got 13.3 volts. Unplugged, I got 10.5 volts. So the 28 month old 12V Battery was not able to hold a charge.
The shop manual says:. When the vehicle is parked, shut off and plugged in, the Secondary On-Board Diagnostic Control Module A (SOBDM) charges the 12-volt battery directly without using the DC to DC Converter Control Module (DC/DC). Once the car is 'started' the DC/DC converter can take over using the high voltage batteries.
So I plugged the 120V charger back in, got in the car and 'started' it, got the "still plugged in" idiot message, while still 'on' got out again and unplugged the charger cord. So the charger cord is one way to 'jumpstart' these cars when the 12V battery goes dead.
I made arrangements with the Ford dealer in Huntersville, NC to swap out the battery at the 'quick change' bay at lunch time. They test the battery to get a code confirming that the battery won't hold charge for warranty exchange. I asked the manager if he had many other electric focus's come in and he saw only one other from a couple who moved to Huntersville from California and they needed the 12V battery replaced.
The size 67R battery is very small and almost exclusive to ford. Per the Ford battery table provided by Trilotus it is 8.27” (210 mm) Long;
6.90” (175 mm) Wide; 6.90” (175 mm) High; With the terminals swapped like a style “R”. Optima does not have one that small. But if they die every 28 to 35 months, I can go back for free replacements at Ford!

whitgallman said:

I got home yesterday at 5 PM and plugged in the eFord.

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What's an eFord?

WattsUp said:

What's an eFord?

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The same as a "Fo-Fo" I do believe.

WattsUp said:

whitgallman said:

I got home yesterday at 5 PM and plugged in the eFord.

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What's an eFord?

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Did you read my update?