Hello All,

I am still running my stock battery (purchased GP2 in April 2013), battery tests as good and I always keep it on a battery tender.

Am I running on borrowed time?

I don't drive it much with only 16K miles on it.

I have the Bavarian technic usb to OBD2 port tool/software that I believe will allow me to update the new battery

Cheers!

 

If you keep it on a battery tender, I would think it should last quite a bit. You'll know when its time to replace when it starts to struggle starting the car, or if you put a load on it without the engine running, the battery will drop too low to start in short order. (like, 5-10 minutes)

For comparison, my 2012 Clubman (with a build date of January 2012) has the OEM battery still. If I let it sit for too long without driving, it will struggle to start the car. But, if I drive it regularly, it still fires up smoothly. Also, if I sit with the engine off and listen to the radio, I can't start the car after 10-15 minutes. I'm about due for a replacement.

 

Thanks forgot to add Production date 09.11.2012.

Also reading that group 34 may fit, may have to rotate the battery due to terminal sides, anyone else confirm?

Have one of these since all my batteries in my vehicles are AGM now.
odyssey obc-20a battery charger

 

Whether the battery starts the car is actually quite a poor test. Why?

As a battery ages it gradually loses capacity to sulphation of the plates. On a battery tender, that's definitely a slower process. But still, at 9 years old I expect you've lost a lot of capacity.

It only takes about 10% capacity to start the car. So the battery capacity is dropping, and dropping, and you think it's fine. But if I sold you a new battery that had 20 Ah instead of 80 Ah you wouldn't be very pleased, would you?

Then one day, probably in winter and on a cold morning, as that's when electrical demand is greatest, and usually when it's the most inconvenient, the capacity dips below what you need and you're stuck.

So how much do you care about getting that last few %, and last year or two, out of the battery?

Personally, I change them at 5 years now as I'd rather be sure of the car starting when I need it.

 

Many new battery charges claim to de-sulfate the battery plates. Buy one and give it a try. What do you have to lose?

 

I use the Midtronics PBT-200 battery tester, same at what some of the battery stores use to test batteries.

https://www.midtronics.com/testers/pbt-series/
Still tests at 100%

 

Those testers test the cranking current, not storage capacity.

The way to test capacity, measured in amp/hours or Ah, is to do a test where a load of C/20 (where C is capacity, so an 80 Ah battery gets a 4 amp load) is applied, and measure the time taken to drop to 50%, which should be 10 hours.

There's no way a 9 year old battery hasn't lost a lot of capacity, and is also aged in other ways. The final end of most batteries is a grid failure where it shorts internally due to deterioration of the grids / plates. Another failure is where the buildup of sulphate at the bottom of the battery reaches the plates.

Again, I'm not saying you shouldn't wait for it to fail, just that might be inconvenient. Who wants to fly in one of those airliners where they wait for the parts to fail, instead of replacing them on an established schedule? Worst case, you waste a year of battery. Good news, sounds like you should get 9 years out of the new one.

If a battery is $100, and you change it prematurely at 9 years, when it could have lasted 10, you are spending $1 extra per year of ownership, to avoid a potential stranding.