Subaru Outback Forums banner
1 - 20 of 23 Posts

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #1 · (Edited)
My 550 CCA battery was getting weak over time with short trips. I had it tested and it was at 309 CCA. I charged it up and had it tested again at 511 CCA. I then had the ECM update done at the dealer yesterday. It's the one that supposedly fixes the battery getting weak over time with short trips. Anyway, the battery is from Advance Auto, two years old, and is rated at 550 CCA. The dealer tested the battery and said it failed. The report says it tested at 423 CCA. The exact wording on the report says "Battery fails to meet industry accepted standards." But, if I remember correctly, the OEM battery was rated at 360 CCA. So how can 360 be ok but 423 fails? If it is because the test rates batteries on a percentage of what it's SUPPOSED to be, I can understand the "fails" statement. But if 360 is deemed good when the car is new, 423 should be good now, right? In other words, just because the battery isn't what it was when new (550), doesn't mean it should get a "fail" mark. My thinking is that now that the ECM update has been done, my battery will be fine. I might buy a CCA testing meter so I can monitor it myself.
 
  • Like
Reactions: Dantrax

·
Registered
2010 Outback 3.6R 2014 Legacy 2.5i
Joined
·
3,326 Posts
CCA is directly related to temps and most ratings are at 0F.

I am not aware of Subaru batteries being so low on CCA rating. The min that I know of is

SOA821B100 at 525CCA
 

·
Registered
2015 3.6R Limited w/ES
Joined
·
4,460 Posts
My 550 CCA battery was getting weak over time with short trips. I had it tested and it was at 309 CCA. I charged it up and had it tested again at 511 CCA. I then had the ECM update done at the dealer yesterday. It's the one that supposedly fixes the battery getting weak over time with short trips. Anyway, the battery is from Advance Auto, two years old, and is rated at 550 CCA. The dealer tested the battery and said it failed. The report says it tested at 423 CCA. The exact wording on the report says "Battery fails to meet industry accepted standards." But, if I remember correctly, the OEM battery was rated at 360 CCA. So how can 360 be ok but 423 fails?...
You're correct, early 4 cylinder Gen 5s came with 356 CCA batteries. Apparently Subaru determined that figure was sufficient (although feedback was mixed on how they did in single digit temps) but those batteries were notoriously short-lived. IIRC, Subaru eventually started replacing them with 490 CCA batteries, which I believe was what they were using all along in the 6. Anyway, sounds like you should let AA test your battery to see if it's eligible for replacement.

CCA is directly related to temps and most ratings are at 0F.
All CCA ratings are for 0F, that's how the figure is defined.
 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #4 ·
it’s a two year warranty so AA won’t replace it. My 3 year warrant F150 battery is 7 years old and my Volvos is 10.
 

·
Registered
2012 OB , 2017 Impreza
Joined
·
3,968 Posts
CCA is directly related to temps and most ratings are at 0F.
AGREED!!

CCA (Cold Cranking Amps) can ONLY be accurately tested at 0F. Any test for CCA at other ambient temperature is an estimate.

There are other metrics for a battery which can be measured.
  • CA (Cranking Amps) measured at 32F
  • HCA (Hot Cranking Amps) measured at 80F
  • Ah (AmpHour) Essentially how many amps which can be drawn for an hour (Folks who go camping should pay attention to this one)
  • Internal resistance... the lower the resistance, the faster a battery can release its power into a load
  • ...etc

Also, beware that a battery is like a steel-chain, it is only as strong as its weakest cell. A car battery contains SIX cells. (~2v each) There is always a 'lazy' cell. With normal usage, this 'lazy' cell may never get fully recharged so it reduces the capability of the entire battery.

It is recommended that a car battery is "equalized" on a regular basis. (Essentially a controlled overcharge which does not overheat the battery) This will bring ALL the cells up to a fully-charged state so they are all working in unison again.

Back to the subject:
My recommendation would be to "equalize" the battery by trickle-charging a minimum of 8 hours. Then use the battery normally for several days. Finally, re-evaluate the condition of the battery.

ADDITIONALLY:
Most autoparts stores will be happy to test your battery at any time using a handheld gizmo. (battery remains in vehicle) Just beware their agenda is to sell you a battery.

If you still wish to get your own battery tester, I have this one and with regular use, you can graph the condition of your battery. (it even tests Internal Resistance)

 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #6 ·
That’s the exact tester I’m looking at getting. Thanks.
 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #7 ·
UPDATE: Ten days ago I had the dealer do the ECM update according to the TSB. When I left there, the CCA were 509 (550 is marked on the battery). Not bad for a two year old battery I guess. Anyway, we've driven the car at least 20 miles everyday since then and 2 days were over 100 miles. I just now went to Advance Auto and it tested at 404 CCA. So is the battery just old? And if I did buy an Optima AGM Red Top, how would that help? I mean if there's a draw somewhere, that one is going to slowly lose strength too, right? What is going on? I have it on a charge now. Not a trickle charger, a regular charger. When I hooked it up, the needle went up to "battery assist" which means the battery is very weak. I will bite the bullet and buy a $225 Red Top if it will be the answer but I'm skeptical that it is.
 

·
Registered
Outback 2017
Joined
·
56 Posts
I would recommend replacing the tiny stock battery with a much larger one - the space easily fits one that is MUCH more powerful. Almost like they intentionally designed the car for that size battery and then downsized it later......

I did mine with an almost new battery - went to costco and got the largest one that physicall fits (costco seems to have the best deal for high quality batteries). I vaguely remember buying a size 24? But also be careful which way the posts (positive and negative) are aligned as theres also a reverse size 24 that makes attaching the terminals a bit harder. Batteries perform worse in very cold or very hot conditions and stressing your battery also lowers its life expectancy. If you have ever killed the battery completely or almost completely then it might be dead just from that (can even happen with a new battery if its fully drained)

Anyways best $120 I ever spent (approx). Last thing you want is your battery to die when its negative 10F in the middle of the night and your trying to get to your campground
 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #9 ·
I did replace the stock battery with this one. The OEM was 356 CCA (do you believe it?) and this one is 550. But I’m thinking it’s the RC (reserve capacity) that I need more of.
 

·
Registered
Outback 2017
Joined
·
56 Posts
Must have missed that

I believe the battery I have from Costco is a size 24 or 24F (I went for the one that seemed to have the best balance of reserve and CCA)

I believe this is what I have:

Size 24
CCA 750
CA 935
RC 130
Ah 70 ish
150/160$ approx

I usually go by the Ah size instead of RC - honestly dont even know how they calculate RC or what it means - Ah is the actual capacity of the battery so that seems like a better metric. I put my stock battery that was still good but obviously way, WAY smaller into one of my family members cars. Interstate makes very good batteries and also some mediocre ones but Costco generally only buys the higher end stuff and has a great warranty.

If you are having this many issues though I would think you have some kind of phantom draw or device slow draining - have you added any electronics to the car like a wired in dashcam or a larger sound system? Also if you leave an OBDII reader in the OBDII port it will drain the battery slowly - learned that the hard way killing two batteries in my old Subaru.

edit: Leaving the rear hatch open even with the car locked and everything off will also continually drain the battery
 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #11 ·
I’ve added nothing. It is pure stock. I leave a phone charger plugged into the cigarette lighter but it is dead when the car gets shut off.
 

·
Premium Member
2018 2.5i Limited; "Wanderlust II"
Joined
·
580 Posts
  • Like
Reactions: Pika721

·
Registered
Outback 2017
Joined
·
56 Posts
Could be some other phantom draw then - I believe there are ways to measure draw when the car is fully off
 

·
Registered
Joined
·
72 Posts
I just put in a group 34 AGM in my 2017.
the post are in the right place and it fit In the spot.

Battery Spec: 740 CCA; 925 CA; 115 Minute Reserve Capacity; 3 Year Free Replacement
 

·
Premium Member
2016 Outback Premium 2.5 CVT w/EyeSight+SRVD
Joined
·
7,783 Posts
I usually go by the Ah size instead of RC - honestly dont even know how they calculate RC or what it means - Ah is the actual capacity of the battery so that seems like a better metric.
The two terms ... Ah and RC ... are directly related. Both describe essentially the same battery property, just expressed in different units: Ah in Ampere-hours, and RC in minutes. Apparently, RC was introduced by some marketing genius based solely on the presumption that American consumers would prefer the familiar term minutes over the less-familiar and geeky-sounding amp-hours. (Ah is still more commonly used than RC in most of the rest of the world.) Either way, when it comes to batteries a bigger Ah or RC number is generally better.
 
  • Like
Reactions: Dantrax

·
Registered
2018 White Outback Touring 2.5i
Joined
·
792 Posts
I don't know if this is a recommended test. So ymmv. If I didn't use my car for a weekend or a few days I would do the old push start button twice (no brake pedal) and then hold the home button and 6 presses on the tuning knob to bring up the vehicle monitor menu to check the battery voltage. As the OE battery steadily went down to 11.1 volts after sitting around for a couple of days, I replaced it. (it was maybe a year old) I bought a Walmart Maxx Everlast group 24 battery. Same size and terminals as group 25 OE battery. (group 34 is 1" lower) I brought my battery load tester with me to Walmart and tested the newest date coded battery on the rack. I brought it home and put it on my trickle charger overnight and then installed it. I just checked it recently and it's down to 12.2 volts so I'll have to load test it again soon but at over 12 volts I still trust it to do what it's supposed to do.
 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #17 ·
Ok, another update: Dantrax post made a lot of sense to me. I don't really like Walmart so I looked everywhere else for a group 24 battery that was strong. The best I found was.....Walmart. Got the same one as Dantrax. I bought one, charged it up and installed it. I saw a youtube one modifying the battery wrap so I did that to fit the bigger #24. It is now on a trickle charger until it floats (which shouldn't be too long). I'll keep you guys posted.
 

·
Registered
2016 2.5i Limited, 2013 Tesla Model S 85
Joined
·
1,291 Posts
I do not believe dealer nor battery store can accurately test CCA. Cold Cranking Amps is tested after the battery has sat many hours at 0°F or maybe 32°F. Look it up, for this discussion all that matters is they didn't freeze your battery before testing.

They can test CA, Cranking Amps, at ambient temperatures. However many of these test sets are badly out of calibration so as to give big happy numbers, "This battery is good, no warranty for you!" Or low sad numbers, "Your battery is bad, you must replace!"

Reading this thread I don't really understand the OP's problem. Outback will start with 100A. Batteries usually fail with a dead cell. Easy enough to detect with a voltmeter. If at or near 12V shortly after a proper drive then you have a dead cell.

The OE battery requires maintenance. Every 3-6 months pop the caps and check "water" level. Fill to the indicators with distilled water. It probably will not last 2 years if you fail to do so.

Going through the replacement exercise I observed no vendor offered an AGM replacement for Gen5 Outback unless they were a boutique brand offering nothing but AGM for everything. Ford uses AGM in ASS (Auto Start/Stop) vehicles but wet lead acid without ASS. The ECU is supposed to be coded via OBD port to know what battery is connected. Pb-Acid or AGM, and size H6, H7, or H8. So I installed a wet battery in the Outback rather than pretend I knew better than the battery vendors. My Ford has ASS and AGM.

Something everyone might consider is one of the Bluetooth Battery Monitors you can buy for about $35. Logs battery voltage every 3 minutes. Stores the past 30 days. Samples more often when it thinks the car is being started so it gives a "starting voltage". That is pretty hard to catch with a simple voltmeter. Makes it easy to see what is happening, how your battery is being charged or discharged. You'll see the evaporative emissions test run 5 hours after the engine was turned off. Hits the battery pretty hard for a few minutes running a pressure test of your gasoline tank.
 

·
Registered
2010 2.5 CVT Limited
Joined
·
2,215 Posts
it’s a two year warranty so AA won’t replace it.
That's kind of a crappy warranty.
Batteries typically will have 1, 2 or 3 year free replacement. Then the pro-rated warranty kicks in.
But Advance won't do anything? That's a bummer.
 

·
Registered
2016 Outback Limited
Joined
·
237 Posts
Discussion Starter · #20 ·
N4HHE, thanks for all the good thoughts and info.
I’m the OP and can address some of your issues. I do know that CCA are tested at 0F but that isn’t the point here. With the same test equipment, and the same person, at about the same temperature, the amps are dropping. That’s the real issue. It might not be the correct amperage number, but the fact that it’s lower than before is what the concern is. Also, I do maintain my batteries well. Distilled water as needed, trickle charge but not overcharge. I have 8 batteries here that I maintain as most are only used occasionally. It is very likely that the battery has a bad cell. And an AGM battery, although a great battery, I didn’t think was the answer. I went with a group 24 wet cell. Bigger battery, more CCA, CA, and AH (RC). That Bluetooth thing sounds interesting. I might get it. I do have a meter and check the voltage frequently. And I soon will have a CCA tester so that will give me another way to test.
 
1 - 20 of 23 Posts
Top