Vacation Mode?

[Dag]

When leaving the car sit for a few days, is it best to unplug the charger, or is there a reason to keep it plugged in to help preserve the 12v battery?

 

I don't want to come home to a dead battery, but I also think leaving it plugged in for a few days isn't a great idea either.

 

Thoughts?

[Russael]

it doesn't matter either way.  Think of your car like a giant cell phone.  You can leave your phone plugged in at all times and the car is no different. :)  Unless you live in an area that gets lightning storms this time of year, there is no reason to leave your car unplugged.

[ctwomey]

Hmm, this is import.  Russael, would your advice change after say, 10-14 days of no use?  Does that increase probs for the 14v?  (partic if you left it unplugged).  

 

We don't have the "vamp" drain that other cars have, but there is the occasional 60 watt usage while waiting to charge, no?

 

Plus, worries about either battery sitting at 0% on a regular basis, right?  That isn't good (or am I stuck in NiMH legacy concerns mentality re "memory effect".)

[Russael]

Hello and welcome to the forum!

 

10 - 14 days of no use should have no impact on the 12V or big battery while being left plugged in.  Most people who seem to have had these issues had bought a car that was built prior to the month of May in 2013.  Mine was built May 8 and I haven't experienced any issues.  Yet.  Most people who have had a dead 12v battery did not leave them plugged in, but one person did have it die while it was plugged in... that was pretty bizarre, but the vast majority had their 12v battery wind up dead while it was sitting unplugged somewhere (even only after 9 hours at work).  I left my car unplugged for 7 days, un-driven, as an experiment over the summer and had no problem.

 

If you want to store the car long term (30 days or more, or even a whole season), they say to store the big battery around 60% charged, and to disconnect the 12V battery which will save that too.  The manual describes how to store the car in detail.

 

You definitely do not want to store a lead acid battery at 0% or 'discharged' since they sulfate.  Deep cycle lead batteries can deal with it for a period of time, but starter batteries for cars don't like it and it occasionally kills them.  Same goes for alarm/UPS or other small batteries.  I'm not sure what storing a Lithium ion battery at a fully discharged state would do, but the general rule of thumb is to store the batteries with a charge in them.

 

So far, nobody has completely killed the big battery in the car.  The software that came with the Energi does not allow the battery to be either fully charged, or fully discharged.  It think it only charges to 90 or 95% (your screens will still say 100% charged), but won't go further than 70 or 80% discharged.  The engineers at Ford did every possible thing they could do to preserve that battery and give it the longest life they could.

[ctwomey]

Sorry, I should have been more precise: for work travel, I'll likely want to leave it unplugged for up to two weeks, at an airport long term parking.  Sounds like your experiment of 7 days, Russsael, suggests there shouldn't be a problem.  Looks like FusionEnergi has done similar length experiments successfully too.  I'll report back after the first such trip.

 

I hadn't thought of the "long term storage" option in those terms, and would hate to have to disconnect the 14v and reset all settings (particularly after getting off a 12 hour plane flight or such).  But it was good for me to review what that entails.  Sounds like "fuel freshness mode" is a very rare thing that wouldn't apply in such a case (my hybrid kicks in several days a week), and that must only go on when being operated, I suspect.  And I'll stay away from MFM checks, disable autoupdate there, turn off GO times, etc.  Cross my fingers that i don't have mczajka's fan short (seems unlikely).  

 

My kids regularly kill the Li batteries in their hand me down first gen iPad, leave it dead for a week, and then recharging it.  I haven't done careful time tests, but the battery life hasn't collapsed on it.  I suppose the 300v Energi battery might be a little different though.  :-)  

[Russael]

I think there was one or two people who have left their cars unplugged for that timespan and had no issues.  If you do have an issue, there are 'jump start' posts under the hood which will get you going... just don't store your jumper cables in the trunk. :)

 

Fuel Freshness mode... I thought the car would intermittently run itself monthly or something to keep the motor lubricated, but now I'm thinking that it actually won't activate until it literally hits 18 months with no fuel added, and will at that point run itself down to 1 gallon of gas regardless of how much charge is in your high voltage battery.  So far, I've driven my car solely as an EV (just went over 2k miles) and have not had the motor come on at all.  Winter is probably going to change that though.  Yay for a 11 mile round trip to the office.

 

Go times won't need to be deactivated or deleted since the car won't be plugged in.  Those only work while it is connected to a power source.  If you left the car plugged in, there's a vacation mode for Go Times, but I just delete them all (I don't trust the go time vacation setting as it came out of it once).

 

To my knowledge, lithium batteries come with their own computer controller which keeps them from going totally dead (device just dies) and keeps them from overcharging as well.  They monitor the temperature of the battery and will either reduce or stop charging until they cool.  They're kind of a dangerous battery so they monitor that thing closely.