Car Battery Shenanigans ... Do you know your battery date stamps?

How many people know how old their car battery is?

They are expensive and to many a little mystical - they work one day and not the next - but when you go in for a routine service, how would you know if you came away with the same unit? What if one of the boys out the back decided your battery was newer than his and did a ‘midnight spares’ ? Would you know the difference after the shop pressure washed your engine bay and everything looked new again.

I’ve heard two stories recently about this kind of thing - maybe conspiracy theorists, but who knows …

One of the signs might be the codes stamped into the battery - I’ve checked two of mine, a Century with D21BB and some distance over, a Q in the middle of the top of the battery - another, some noname brand has D1JA and a C on the negative terminal. One wonders if there is rhyme or reason to these and to that end Century publish as somewhat helpful chart like this:


Which isn’t entirely clear given most of the month has more than one digit. I’ve read elsewhere that the years roll over every 10 and they miss letter I (India) so as not to confuse with numeral 1 (one), as no battery is likely to last that long I guess. So maybe my Century battery is Day Shift, 21st of February 2018?

Secret decoder ring anyone?

I wonder how many people get a surprise when they are told their battery is 3 years older than their receipt says?


Shouldn’t be an issue if a flooded Lead-acid battery is stored dry since manufacture.
It will be more of an issue with sealed and vented, Gel, AGM etc type batteries which are shipped from the factory with acid already in them.


True, but my understanding from what I’ve seen done is the dealer stamps at time of sale - thats what they did with my Century - so my receipt and my battery say the same thing today, but if I get an oil change and George Shonk & Co and Johnny the apprentice decides his failing battery might be easily swapped for mine - when I go back for a warranty claim, my dealer will say “your receipt doesn’t match the stamp” …

I know the people I buy Century from receive their batteries dry and get them on acid as needed … gee, sounds like some of those old Uni parties … ahem …


From what I understand there is no standard as to how the date of manufacture is stamped/printed/written on a battery. Century may have a system but another may use their own. Some include codes to tell which actual factory or assembly line the battery came from (sometimes to do with quality control or stock control).

Exide Battery date coding:


Typically the last couple of batteries purchased here have come off the shelf.

No delay as acid filled and raring to go!

No magic codes stamped at purchase, just a store receipt at Mitre 10 or SuperCheap.

How long were they on the shelf before sale?
Perhaps the codes help. Suspicion is up to 6 months, but who knows?

I simply write the installed dated in marker pen on the top of each battery just in case I forget.

A while back a tyre shop sold batteries with three different warranties. 12 months, two years, or extended. Same battery, different pricing. Oh, and Yes, no delay to acid fill! They were ready off the shelf.


I’d like to see them try to do a sneaky swap of my battery. It’s a Japanese domestic market battery. It would be very obvious if they replaced it during a service. I’ll add that based on previous experience, it’s likely to last a lot longer than a local.


Same anecdote here.

The challenge would be to get the inside low down on what it is that makes all the difference. The cynic in me says that the local manufacturers and importers of cheap product from OS are driven by turnover, rather than product quality.

Are Aussies paying premium prices for minimum quality products. Car batteries would seem a great Choice product test?


Yes, our last battery (a Japanese one new with the vehicle) lasted over 9 years. The local RACQ didn’t believe us until he looked under the bonnet to check and saw that it was a OEM one. He indicated that most vehicles don’t get anywhere near the same battery life.

Our second battery has been going since March 2012…(and touch wood), still going strong.


Choice’s US sister, consumer reports (member content) tests and reports on car batteries as well as publishes a buying guide.

Unfortunately their results are not applicable to our market but their methodology could be used by Choice to ‘hit the ground running at full speed’. It could be another organisation here does similar testing where a collaboration might result? I’ll link this in ‘request a test’ to formalise it.


We had an expert from a major battery manufacturer come and talk to our group. It was most interesting. We asked why car batteries no longer last like they used to and he said back then they used lead. Today it is a lead alloy of some sort.


I still have the original battery, in my I Load diesel, 2009 model. A no brand, OEM, CCA 720. Every winter I trickle charge it over night. All other batterys I have date marked with a paint marker, I always forget the purchase date. So far no attempt has been made, at services, to interfere with it.


I’ve also asked the question about how long the batteries last.

The answer I got was something to the effect of: Vehicles have more and more electronics which (almost constantly) draw power from the batteries. They need longer trips to fully recharge and refresh. Most people don’t do the longer trips often enough to keep their batteries in peak condition.


My mechanic suggested I take my car for a drive at least once a week for one hour.
My first Toyota battery lasted 8 years, and it’s now nearly 4 years into the second one.


It’s probably a lot less expensive to put a trickle charger on it for a day if not driving for any length of time. Running a large engine just to charge the battery is a very inefficient use of fuel.


Thank you @gordon.
My parking space at the Flats is open to any one coming in off the street, and I’d be uncomfortable leaving a charger unattended for any length of time.

Usually I drive from StKilda to Mordialloc
without stopping, I take it slowly and make it in about an hour, round trip.
It’s a 4 cylinder car, the cost of petrol is about a cup of tea or coffee I’d be having at the local coffee shop anyway.
And the drive along Beach Rd is a very beautiful one. :slightly_smiling_face:


Has anyone noticed how expensive car batteries have become since the carbon tax was introduced (I realise it has been repealed since), anything that produced energy went up in price.
I found a battery in an auto store recently for a 2009 Mazda3 without i-stop, $469.95.
Someone is making lots of profit from car batteries.
I would welcome a Choice test or investigation.


After this therefore because of this?


The old trick is to mark your battery, and any other parts like spark plugs, oil filter, air filter etc before you deliver the car for service. Use some liquid paper and put a spot in a secret place on any parts. Even if it can be seen, it’s a signal to service staff that you are checking up on them so they are less likely to try and dud you. I always check the dipsticks too and if the oil is dirty the car goes straight back. You only need to do it once and they are very careful after that. One Ford dealer used to give me the old alleged parts, except that I checked on one occasion and they weren’t from my car. It’s actually theft, so don’t hesitate to get legal with them via your auto club. Regarding the battery, they do have serial stamps, but are difficult to find sometimes. Good luck.


Usually I drive from StKilda to Mordialloc
without stopping

If I’m ever driving in your area I’ll be sure to cross intersections very cautiously :wink:


No worries,@slb, I’ll make sure to stop for you!:wink: