Slow draining battery on Subaru Forester 2005

[RonC6]

Yea, my problem was I left it on for a few months (forgot about it over winter) and it ran out of electrolyte .. and then whole garage smelled like rotten eggs. I believe it was on the 2 amp setting.

 

[Dick Foster]

As with almost anything, you want to get a tool designed for the purpose. Clearly the charger you used was okay for topping a battery up, say overnight but it wasn't a tender or maintenance charger.
There are a lot of batteries used in applications that see infrequent or seasonal use so naturally there are chargers designed for those applications. Boats etc. They all are programmed to top up then shut down so are safe to leave connected for extended periods of time.
Some even do preventative maintenance like occasionally checking for and desulfacaing the battery by applying rapid pulses which helps break down the sulfer crystals that coat the battery's anode plates.
The leading cause of battery failure is sulfication. The rotten egg smell is from the sulfer and sulfuric acid used in car batteries. As the coating builds up, the battery's internal resistance increases, which then decreases the current the battery can supply. It gets worse and worse until it eventually reaches the point of not having enough capacity to start the car.

 

[bmay10]

My 2005 Forester's battery drains slowly over several weeks. I put a slow charger on it to recharge, but it continues to slowly drain its charge. I read that the car has certain electrical functions with its computer that continue working even while not running. However my 2010 Forester doesn't have this same problem, so I suspect there is some short somewhere in the system that is causing a greater drain on the battery's charge. Any suggestions on how to diagnose this issue or how to locate a short?

You also might want to be sure the auto off is not ever turned on. I had to call roadside assisance becasue of this auto off button. Mine was same senerio wasnt driven much which the alternator did not run enough over time to charge battery fully. I bought a device that now leaves the auto off switch where I put it either on or off and stays that way when restarting

 

[Dick Foster]

You also might want to be sure the auto off is not ever turned on. I had to call roadside assisance becasue of this auto off button. Mine was same senerio wasnt driven much which the alternator did not run enough over time to charge battery fully. I bought a device that now leaves the auto off switch where I put it either on or off and stays that way when restarting

Autostopeliminator is a very good thing, not only for cars but for thier owners too. Auto stop is hard on batteries, engines and people.

 

[Raymond3006]

My smart Tom Tom charger (which I love) is switchable for cars/bikes and battery type/chemistry. It has a "program" to charge each after reading the battery. Pretty cool stuff.

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CAUTION !
Some of the "information" contained in your above EXCELLANT posting has been known to get some Members of these various "S" Forums "excommunicated" for violating the FAITH portion of being a "S" operator .... !!!!
I was kicked off for similar "unacceptable" postings , which they call SPAM , for an excuse to bring the hammer DOWN !!!

 

[bmart]

?

 

[Raymond3006]

I wrote that "S" Alternators should be quickly set to 14.0 Volts by the ECM for quick re-charging after Starting a "S" vehicle , especially while the Vehicle is in PARK , or in NEUTRAL , or even while first driving : so the Battery would stay in a High State of Charge , instead of slowly degrading due to Sulphation of the battery Plates caused by Chronic Under-Charging ....... : for that I was "excommunicated" for a while ..... !!!
The Above Post shows exactly that Charge Profile .... 14.xyz Volts (which is higher than my 14.0-Volts recommendation !!!!!)

 

[Raymond3006]

As PER the Tom-Tom info (above) you can safely TRICKLE CHARGE you battery all the way to 14.1-Volts ... INDEFINATELY !!!

 

[Dick Foster]

It runs out there was a flaw in the starlink system where by Starlink drains car batteries constantly attempting to call on an obsolete, outdated and inactive cellphone system.

From what I've seen Starlink is plagued with design shortcomings and design flaws, so I've discontinued mine.

I suggest they scrap it and start over with a clean sheet of paper.

 

[Raymond3006]

It runs out there was a flaw in the starlink system where by Starlink drains car batteries constantly attempting to call on an obsolete, outdated and inactive cellphone system.

From what I've seen Starlink is plagued with design shortcomings and design flaws, so I've discontinued mine.

I suggest they scrap it and start over with a clean sheet of paper.

For those who are first starting with this Starlink MESS, there are several ( 3 ) solutions
(#1) Pull the DCM Fuse , but you will loose some features most people still want ;
(#2) RE-POWER the DCM FUSE from a SWITCHED (not alive when vehicle is Not Running !) . This change seems daunting, but is actually simpler than ...
(#3) rewiring the inside of the DCM-System ... !

The Re-Powering consists of removing the DCM-Fuse from the Factory Position , and not using the Origional Power Source, but shunting its Power-Source from the near-by Relay-Switched-Source (thru an ADD-A-FUSE dongle) , which Output-Contact ( "b"-contact ) is DEAD when the Vehicle is OFF ... ! This Switched Voltage is available on/from ANY of the Fuse Positions coming from the Relay, these have a BROWN Plastic Shroud , compared to the Origional one being GRAY; the relay described is the one immediately at the Head of the BROWN Group of Fuse Positions.
Your actual Wiring Technique is left up to you , I used several of those Add-A-Fuse devices , but any combination of them (to hold your DCM Fuse) and simple wiring shunts will also do the Job ... ! GO FOR IT ... !!!!!

By not giving The "S" System a chance to be kept on-line while the Vehicle is NOT RUNNING , you forever remove it from being able to KILL YOUR BATTERY , while your Vehicle is Parked ... at Home , a shopping Mall , the Airport , or at a remote location FAR AWAY FROM ELECTRIC UTILITY LINES .... like while Trout Fishing in the Mountains !!!

Now , go OUT and Enjoy the Real Reliability that you thought you had already Purchased !

PS : You might also want to replace your "OEM" Boat-Anchor "battery" with one having an 800-CCA Spec ... as there are still OTHER GREMLINS awaiting to attack your "S" Electrical System .... !!!
And ALSO , add a Battery Maintainer to your Vehicle's Parked-At-Home Proceedure ...

 

[Raymond3006]

For those who are first starting with this Starlink MESS, there are several ( 3 ) solutions
(#1) Pull the DCM Fuse , but you will loose some features most people still want ;
(#2) RE-POWER the DCM FUSE from a SWITCHED (not alive when vehicle is Not Running !) . This change seems daunting, but is actually simpler than ...
(#3) rewiring the inside of the DCM-System ... !

The Re-Powering consists of removing the DCM-Fuse from the Factory Position , and not using the Original Power Source, but shunting its Power-Source from the near-by Relay-Switched-Source (thru an ADD-A-FUSE dongle) , which Output-Contact ( "b"-contact ) is DEAD when the Vehicle is OFF ... ! This Switched Voltage is available on/from ANY of the Fuse Positions coming from the Relay, these have a BROWN Plastic Shroud , compared to the Original one being GRAY; the relay described is the one immediately at the Head of the BROWN Group of Fuse Positions.
Your actual Wiring Technique is left up to you , I used several of those Add-A-Fuse devices , but any combination of them (to hold your DCM Fuse) and simple wiring shunts will also do the Job ... ! GO FOR IT ... !!!!!

By not giving The "S" System a chance to be kept on-line while the Vehicle is NOT RUNNING , you forever remove it from being able to KILL YOUR BATTERY , while your Vehicle is Parked ... at Home , a shopping Mall , the Airport , or at a remote location FAR AWAY FROM ELECTRIC UTILITY LINES .... like while Trout Fishing in the Mountains !!!

Now , go OUT and Enjoy the Real Reliability that you thought you had already Purchased !

PS : You might also want to replace your "OEM" Boat-Anchor "battery" with one having an 800-CCA Spec ... as there are still OTHER GREMLINS awaiting to attack your "S" Electrical System .... !!!
And ALSO , add a Battery Maintainer to your Vehicle's Parked-At-Home Procedure ...

Small "mistake" , in above Info : The Output of the Relay actually is on a point electrically described as "a2" instead of "b" ;
"a" being a Normally Open Contact , "a1" being the "+12" coming to that "a" Contact , and The Switched +12-Volts coming out of the Relay on its "a2" position.
Remember to use a Digital DC Voltmeter to confirm all wiring BOTH "before" , and "after" to assure that you have the right changes before permanent usage