Battery Failures

[FrankB]

The Battery failed in October, I found flat at 5v one morning with the boot lid open. The night before had been Halloween so not sure when or how the boot lid became open or was left open.  Either way the courtesy light should not have drained the Battery after only 8 to 12 hours.  Got a jump start and took it to the local deler.  The Battery was replaced free although it was just out of warranty.  That was nice.  But then it was the 4th Battery on ths car.  The 3^rd was shortly after I bought the car, the 2^nd I found out about when discussing the failures, it was shown on the maintenance records.  The dealer cannot explain what is happening with the battery failures. The charging system is fine. There is no obvious drain on the battery.  The dealer did say that they had other Subaru batteries fail.  Is this a common issue with Subaru batteries?

[Delta Mike]

You say "There is no obvious drain on the Battery."

How did you come to that decision please?

Did you, for instance, measure the IOD?

IOD = Ignition Off Draw, which is notoriously difficult to measure. 

 

[Tidgy]

Gone through a few on mine in the past 18 months and turns out there was a fault on the charging circuit.

[FrankB]

"There is no obvious drain on the Battery." - I am relying on what the garage told me.  I don't know if an IOD test was done.

Thanks for the replies.  The dealer said the car was charging OK.  An intermittent fault?  I'll have to keep an eye on it.

Thanks again.

[Justin Time]

Battery drain issues on late model Subarus is a very common issue (see various threads on this site and many others internationally).  A few key suggests for you:

1. Never leave the boot lid open for more than 10 mins. and if you do need to (say you're camping or loading lots of stuff etc.), then do the 'carabiner trick'.  Works with mine and easy to fix. or do this: 

2. Always drive with the sidelights on and NEVER in auto light setting, unless you do decent mileages and avoid lots of short journeys.  The charging algorithm on modern Subarus is designed to flatter the mpg figures so doesn't engage the alternator to recharge the Battery (thus less load on the engine so better mpg) unless it really needs to (which is never enough!).  Driving with side lights on (or AC, etc.) over rides the algorithm and forces constant alternator charging.

3. Go through all the car settings and switch off auto downloads and wifi connection, etc. as the car will keep searching for updates even when switched 'off' and parked on your drive etc....draining the Battery.

4. Lots of OB owners, like me, tape the boot roof light 'off' so it can't be accidentally knocked on.

Hope you get it sorted.

[FrankB]

Thanks very much for the sound advice which I will follow. Also bought a jump start Battery pack – belt and braces.  A bit disappointing to hear it is common issue.  But I have some good news about the loss of my satnav maps which you can see in my other post.

[Justin Time]

28 minutes ago, FrankB said:

Thanks very much for the sound advice which I will follow. Also bought a jump start battery pack – belt and braces.  A bit disappointing to hear it is common issue.  But I have some good news about the loss of my satnav maps which you can see in my other post.

I'm not sure if this is new information, and if it's useful for you or not, but you can access the dealership mode and also the factory mode on your Outback.  It's a little bit different to access on my Gen5, where I press and hold the home button while simultaneously pressing the tune button 6 times to get factory mode.  You are then able to access a range of menus. 

I forget which one of the menus, but it's easy to find once you're in, that has a read out of the Battery health in volts, when the car has either the engine running, or when not running but with the ignition on.  I find this is an easy way to quickly monitor the health of my Battery, both on start up and/or just after the car has been stationary for a few hours to see if there's any drain.  It saves the hassle of getting a multimeter out, popping the bonnet and connecting the leads to the Battery, etc.

Here's a relevant thread from the US OB forum which describes the access to the dealership mode in a Gen6 OB. 

 

https://www.subaruoutback.org/threads/how-to-access-service-menu-gen6-outback.548488/

 

Ah.... looks like I've posted this info before:

https://uk.subaruownersclub.com/forums/topic/27361-secret-factorydealer-settings-access/

[FrankB]

Thanks again.  I will have a look but I am a bit distracted and very pleased to find today that the self levelling and Steering Responsive Headlight (SRH) warning lights have disappeared.  See my post on this - briefly, they came on after the Battery failure, the dealer couldn't reset them and quoted £800 to replace a headlamp control module.