Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.

New Posts Contact us

Just Commodores Forum Community

It takes just a moment to join our fantastic community

Register

How to interpret Battery Voltage reading vs. battery life

diysv6

Active Member
Joined
Dec 17, 2005
Messages
547
Reaction score
28
Points
28
Location
SEQ
Members Ride
VF S1 SV6 STORM A6: VZ S1 SV6 A5
Hello all,

My battery is approx 4.5 years old, (SV6 Auto - Build date July 2015) never been flattened, and driven in mostly south east Qld weather conditions.

I usually check the Battery Voltage screen every few week to see if the battery is "behaving" eg. after a long trip 100/300km, on the next start after the trip, the battery shows as a lower charge voltage eg. 13.x volts. After a few days of normal suburban driving, the battery runs at about 14.8V which is the "normal" voltage under most conditions. My HVAC runs all the time. I don't have any fault indications on the dashboard display.

Today, I noticed the battery voltage was 12.6V after start up, and stayed for a short trip of 7 kms. HVAC was running OK. At about the 6 kilometer point in the trip, I turned on the headlights and the voltage dropped to 12.4V. Turned off the headlights, and the voltage went up to 12.6V. Evidently there was some ECU/regulator function response when the load increased/decreased.

Upon restarting, the initial voltage was 14.8v and dropped within a kilometer to 12.6v again and stayed there.

Is this a conditioning cycle by the ECU to maximise battery life/performance to some preprogrammed voltage/load curve, or is this the pretesting sequence which indicates a battery failing sometime in the near future?

I am happy to buy the designated Holden/AC DELCO battery, as I still have Holden warranty until September 2020. I don't look forward to arguing any MyLink/ECU/HVAC/battery/alternator issues with Allianz who seem to manage the extended Holden warranty now.

Thanks for your thoughts in this one.
 

stooge

Well-Known Member
Joined
Apr 3, 2014
Messages
2,287
Reaction score
1,848
Points
113
Location
wa
Members Ride
ZB Rs V6
First off i feel sorry for you that they sold you a 3rd party extended warranty, lets hope you never have to claim.

With the battery normally a load/stress test is performed to check its life which really just measures the rate of discharge and you cant do this with the alternator putting charge back in so if you want to check it look around for a auto store that does testing like supacheap or goto batteryworld or a store like it and get a test done.
The tests are cheap and doing one may save you forking out $$$ for a battery or save you getting stuck somewhere with a dead battery.
 

lobbie

Member
Joined
Jun 29, 2015
Messages
104
Reaction score
23
Points
18
Location
lambton
Members Ride
vf sv6
First off i feel sorry for you that they sold you a 3rd party extended warranty, lets hope you never have to claim.

With the battery normally a load/stress test is performed to check its life which really just measures the rate of discharge and you cant do this with the alternator putting charge back in so if you want to check it look around for a auto store that does testing like supacheap or goto batteryworld or a store like it and get a test done.
The tests are cheap and doing one may save you forking out $$$ for a battery or save you getting stuck somewhere with a dead battery.
I doubt he had to pay for the extended warranty holden did a 5 year warranty in mid 2015 which would mean it runs out 2020
 

stooge

Well-Known Member
Joined
Apr 3, 2014
Messages
2,287
Reaction score
1,848
Points
113
Location
wa
Members Ride
ZB Rs V6
I doubt he had to pay for the extended warranty holden did a 5 year warranty in mid 2015 which would mean it runs out 2020

If his "extended" warranty is being handled by a 3rd party it means he was not given a 5 year "factory" warranty so whether he paid extra or not it is a bad thing.
just ask the plethora of people that have had to make claims with a 3rd party warranty provider...

the horror stories are mind blowing.
 

lobbie

Member
Joined
Jun 29, 2015
Messages
104
Reaction score
23
Points
18
Location
lambton
Members Ride
vf sv6
If his "extended" warranty is being handled by a 3rd party it means he was not given a 5 year "factory" warranty so whether he paid extra or not it is a bad thing.
just ask the plethora of people that have had to make claims with a 3rd party warranty provider...

the horror stories are mind blowing.
Yes understand that .
In diysv6's post he mentioned holden warranty till 2020
 

stooge

Well-Known Member
Joined
Apr 3, 2014
Messages
2,287
Reaction score
1,848
Points
113
Location
wa
Members Ride
ZB Rs V6
Yes understand that .
In diysv6's post he mentioned holden warranty till 2020
Yep he also said it is being handled by allianz which is what normally happens when it switches from the 3 year factory into the 2 years 3rd party extended.

So it is all a bit confusing because a 5 year holden factory warranty should be handled by holden/gm.
 

Trevor loves holden.

Well-Known Member
Joined
Jun 6, 2019
Messages
3,508
Reaction score
745
Points
113
Location
Victoria
Members Ride
vs commodore
14.8 will be your bcm charging rate so your Alternator is fine, anything over 12.7v will be the charging system, a good battery should rest at 12.7, so I say its on the way out but get the load test done to see if it passes if its close to death then buy a new one to specs..
 

smurfmeister

New Member
Joined
Nov 30, 2016
Messages
17
Reaction score
11
Points
3
Age
52
Location
sunshine coast
Members Ride
vf redline
I wouldn't be too concerned diysv6, if it makes you feel better, my 2014 redline has original battery 5 1/2 yrs old seq weather, low k's going strong. Had tested this year all good. Also had warranty claims through allianz, again no problems. Can't believe how long a battery will last by being in the boot away from engine bay heat. Only got 2yrs out of the collie battery.
 

Holden17

Well-Known Member
Joined
Dec 17, 2016
Messages
596
Reaction score
417
Points
63
Age
62
Location
NthBris
Members Ride
MY16 SV6 ute/MY17 LMF SS wagon
I wouldn’t be too quick to change the battery at 4.5yrs if use has been normal and there are no real signs of it letting you down.

My original VE battery lasted 6.5yrs until I changed it. Still hadn’t let me down but it was winter & I felt it hesitated ever so slightly a couple of times when turning the ignition key. I was on hols so thought it was more convenient to have it changed at the time rather than getting stuck one morning when back at work.

Dad’s VF CalaisV (purchased Dec’16) hadn’t been started since Easter this year. A month ago I replaced the key pod battery and as expected still couldn’t even open the boot. I called the RACQ with the intention of buying a battery from them. The RACQ techie insisted on checking it out properly and got 1.5V but it started to recharge so quickly from his heavy duty pack that he suggested I just put it on a smart charger for 24hrs....ended up taking closer to 36hrs to read fully charged but hasn’t looked like missing a beat since (admittedly I haven’t even bothered reading the dash voltmeter but must have a look now that it is being mentioned here). BTW, he told me the new Commie batteries they carry cost $240 (2yr wtty from memory).

So the Calais battery is now 6yrs old and continues without any issue.

My half dozen previous Commies were all traded in around 3yrs or less so never had to replace batteries with them...
 

Big Red VF-SII Go-kart

I love puddles.
Joined
Aug 3, 2010
Messages
1,166
Reaction score
389
Points
83
Location
Darwin NT
Members Ride
VFII MY17 SV6 (LFX) Sportwagon (SOLD)
Fluctuations in battery voltage under load are normal and recoverable. Pronounced drops not under load or before starting and during running are not. Maybe have your alternator checked out before finger-poking the battery. Just as a passing mention, I and others were amazed that the battery in my much-travelled (now traded off) VZ lasted all of 8 years, finally showing some ill health in May this year when it was replaced.
 
Top