1st Person Experience with depleting the 12v battery
Was working on getting the garden ready this weekend and had the 12v battery go dead. Since I was actively present while the whole thing unfolded, I though I'd pass along the experience.
I had the back doors and the lift gate open, the switch was in the ACC position and the radio was on. No other drains except at the beginning when the interior lighting was on from closing/opening doors. I listened to the FM radio for at least 2 hours and then it acted as it if were losing the station's signal. This lasted for about 5 seconds and then everything went black. I opened the front door and turned the key off/on. No clicks from the relays, no pressurizing from the brake system, and no display on anything. same thing on a few more key off/on cycles. I went inside and grabbed the plug-in battery charger, attached it to the battery. Cut the switch off/on and nothing. Off/on again and the relays clicked and the FEH started right up. I promptly disconnected the charger. I let the FEH run, it went though several ICE-ON/EV cycles as I finished up my work and listened to the radio. After about 30 minutes, I turned the switch off. Let it sit for 5 minutes and then restarted without an issue. It has restarted at least 5 times since then without issue. During this whole process (from the radio cutting out until after the last restart) the battery indicator (little glass eye on the battery itself) was a dim RED. I remember it being dim GREEN earlier in it's life. I've had my FEH since August 2007. So the battery is over 42 months old. I'm betting once you factor in lead time from the battery manufacturer and shelf/build time at Ford, the battery is about 4yrs old. In any case, I'll keep an eye on it and know that a replacement 12v is in my near future. Fair enough. I also need to check the water fill level in the battery. I'll do that this afternoon when I have access to the vehicle again. I'll also check the RED eye/GREEN eye situation. |
Re: 1st Person Experience with depleting the 12v battery
I just had to replace mine. No issues starting mine. I was driving up into the mountains and it started hesitating like it was missing. Turned around and when to the dealership as I thought it was fuel related since i had just changed the fuel filter. Service Dept.checked the codes and said it was the 12v battery. I was quite surprised.
It's been about a month and no problems and it runs like a top. |
Re: 1st Person Experience with depleting the 12v battery
This is a fascinating process for me. Thanks to the
two of you for sharing your experiences. IMO as an old engineer the 12vdc low voltage battery in the FEH is being used in a different set of circumstances then it was primarily designed to do. And that being supplying a big surge ( 100's of amps ) to turn a large DC motor to crank a flywheel to start a car. All of us have experienced the dying car battery syndrome. Over time the cranking gets slower and slower telling us that it's time to change the battery. But in the case of the FEH the lead acid battery goes over the edge of it's power curve quickly and you don't know it's coming till it happens. IMO I would suggest that as your battery gets to 36-months of age that about every 6 months just take it into any of the auto parts stores and they can check your battery. It's all usually free. If you have your FEH maintenanced on a regular basis checking the battery under a load should be a check off item. The last check for my 06 FEH was at a Ford dealer and they certified it to 500A cranking power. And they also confirmed that the charging system is working. My battery is about a year old. Just in case I purchased a Peak Portable Power System 450 Plus. http://www.peakauto.com/electronics-..._systems.shtml An extremely useful device not only for starting the neighbor's car when his battery died, but it powers lots of other things. Along with the jumper cables it includes 115VAC, USB and +12vdc outputs. |
I gotta start reading the manual better
I had thought that the switch in the floor well was for using the traction battery to charge the 12v battery. It turns out that the opposite is true; the switch is used to charge the traction battery FROM the 12v if the traction battery goes flat. I'm not sure how the main battery could go that flat, considering the protections built in.
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Re: I gotta start reading the manual better
Originally Posted by stevedebi
(Post 233706)
I had thought that the switch in the floor well was for using the traction battery to charge the 12v battery.
( traction battery if you wish ) and the LV 12vdc batteries both go dead then if you connect something like my Peak Power Station ( 12dc jumper ) to the LV terminals and go through the 8min recharge process with the switch in the floor well. Then the HV battery will be recharged enough that and you can start the FEH. I think. |
Re: I gotta start reading the manual better
Originally Posted by wilcal
(Post 233712)
I think, and I'm only guessing here, that if the HV
( traction battery if you wish ) and the LV 12vdc batteries both go dead then if you connect something like my Peak Power Station ( 12dc jumper ) to the LV terminals and go through the 8min recharge process with the switch in the floor well. Then the HV battery will be recharged enough that and you can start the FEH. I think. |
Re: I gotta start reading the manual better
Originally Posted by stevedebi
(Post 233713)
Yes, that is the way I read the manual. But I still don't know how the HV battery would go that flat.
the LV battery has some juice in it that it takes very little energy from the HV battery to spin up the ICE. |
Re: I gotta start reading the manual better
Originally Posted by stevedebi
(Post 233713)
Yes, that is the way I read the manual. But I still don't know how the HV battery would go that flat.
I've also found that an AGM (dry-cell) 12v battery solves these types of issues since they can be deep discharged repeatedly. |
Re: I gotta start reading the manual better
Originally Posted by D-mac
(Post 233737)
I found with about 3 weeks' of storage it will go pretty flat. It probably goes even faster in cold climates.
I've also found that an AGM (dry-cell) 12v battery solves these types of issues since they can be deep discharged repeatedly. Here is what the 2008 Owners Manual States: "Low and high voltage battery – storage Your vehicle must be started and run for a minimum of 10 minutes once a month in order to maintain the high voltage battery charge. This will maintain the high voltage battery but it is not enough to maintain the low voltage (underhood) battery and additional low voltage (underhood) battery charging may be required after 60 days. If your vehicle is to be stored for 30 days or longer, the low voltage (underhood) battery negative terminal must be disconnected. Failure to do this could damage your vehicle’s batteries." I don't know if this means it will be depleted, or just begin to lose charge. |
Re: I gotta start reading the manual better
Originally Posted by stevedebi
(Post 233741)
Here is what the 2008 Owners Manual States:......
"Low and high voltage battery – storage... I don't know if this means it will be depleted, or just begin to lose charge. I doubt there is much draw from the LV battery when the FEH is off. I typically can go a week or more without using my FEH and don't seem to encounter a problem. 60-days of storage or beyond I would certainly start that storage period with a fully charged LV & HV batteries. |
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