[apexit4]

Originally Posted by Welcome to NBA Jam

You can get some pretty sweet deals at autozone on occasion.

I've found that Pep Boys carries Bosch batteries, which come with a 3 year warranty. They even offered a $40 discount if you bought online and picked up at the store.

[arkie6]

Heat accelerates battery aging. Cold temperatures extend battery life. Heat accelerates internal plate corrosion which cannot be recovered. Cold temperatures reduce battery capacity, but the capacity returns when the battery returns to normal temperature.

[BMWs4ever]

I replaced my battery finally after 10 years. It was working perfectly although it did not have the green colour in the window. It might have lasted longer but I did not want to take the risk of having it die in the middle of nowhere. :-)

[vilord]

There are 3 different batteries that fit in our E9x's. I'd suggest getting the biggest one (Group 49 / 80AH+). Some of the auto parts stores only listed the smaller size batteries for my E91, but the bigger ones fit fine and last longer.
I would not expect to get the same 10 year life out of an autozone battery that you got from OEM.

[GoRomeo]

My original battery lasted about 8 yrs.

[feuer]

The battery in my BMW lasted almost 10y. Engine started every time but when car sat for day or two the clock and mirror and seat settings will vanish. It became annoying and I knew is just matter of time before it completely fails so I replaced it with Benz battery since was considerably cheaper. The battery in my VW lasted for over 10y, almost 11y. VW doesn't have IBS so the battery one day just didn't crank the engine. I always turn off everything, like radio, lights, seat warmers, HVAC blower motor then let engine idle a little before shutting it off.

[Bilbofraggins]

My son drives a 2008 323i, driven daily. Parked outside last 4 years. Original battery still delivering here in Canada’s maritimes. On the other hand, I just replaced the battery in my 2013 X6M as I was sick of increased discharge messages even though it’s garaged. Never experienced any noticeable problems though...

[e90yyc]

Nice!

My original battery lasted 11 years too! And 275,000 kms, no less!

I was shocked when I went to register the new battery, and saw it had never been replaced. I had all the service records too; same verdict.

Frankly I probably could have stretched it even further, but it was clear the batt was starting to go and I thought it best (for my mobility and the charging system) to bite the bullet and replace it.

Went with OE myself. Got a good deal so it made sense.

Good luck

[Bob Shiftright]

Originally Posted by MGT81

Just wondering what the rest of you have experienced in terms of battery life on your E90s?

My original battery was replaced by the dealer under the "courtesy" warranty program over 8 years ago. Since that time, I've been careful to use a trickle charger.

Last year the trickle charger gave me an error code and shut itself off, as did a second trickle charger. My big charger charged up the battery but the next morning the voltage was under 12 volts.

If it looks like a duck, right? No big deal, the battery was over 7 years old by then.

I dropped the car off with my indy for battery replacement and when I picked the car up, he told me that the car had had a lead acid battery, but it had come from the factory with an AGM battery -- I thought only 'verts and M Cars came with AGMs but apparently my car is heavily optioned and so it did.

But the interesting info was that my BMW dealer gave me a lead acid battery but hadn't changed the coding so the car was coded for an AGM battery.

The coding was wrong and the replacement battery still lasted more than 7 years.

No, I'm not shocked that a BMW battery can last >10 years, but battery failure is probably a bell curve distribution.

[BimmerNugget]

Originally Posted by apexit4

Not everyone has access to batteries that cheap. I think the price you paid for yours is more of an outlier rather than the norm. Warranties that long are becoming more common though.

Does your car have an IBS? If so, did you code it to account for the higher AH rating?

LOL...$130 for a car battery is not an "outlier" price. It's a normal price for a battery. A $55 battery from Walmart is an outlier price.

Autozone, Pep Boys, Advanced auto parts, Sears etc. all sell batteries for $100-$180.

Only reason to pay more than that is if you want an AGM battery which is OE on our BMWs. But to be honest, a regular lead acid is fine. You can get the same exact size battery with same CCA rating and all that but just lead acid instead of AGM at Walmart for $110-$140. If you got BMW INPA or Foxwell NT510/520 you can even register it yourself

[apexit4]

Originally Posted by BimmerNugget

LOL...$130 for a car battery is not an "outlier" price. It's a normal price for a battery. A $55 battery from Walmart is an outlier price.

Autozone, Pep Boys, Advanced auto parts, Sears etc. all sell batteries for $100-$180.

Only reason to pay more than that is if you want an AGM battery which is OE on our BMWs. But to be honest, a regular lead acid is fine. You can get the same exact size battery with same CCA rating and all that but just lead acid instead of AGM at Walmart for $110-$140. If you got BMW INPA or Foxwell NT510/520 you can even register it yourself

I didnt see any at the local Pep Boys, Autozone, etc for below $150 that matched my specs. There were certainly cheap batteries at those stores, just non that matched what I needed. Ended up getting an OEM battery for $180 (thats including a core charge).

Keep in mind not all E90's came with a lead acid battery. And dont forget that switching from a lead acid to AGM will require coding to get the most out of it. Neglecting to do the coding is just throwing money away since the car wont properly adapt to efficiently use the AGM. Conversely, if your car came with an AGM, its probably best to stick with it and not "downgrade" to a lead acid. It is my understanding that some of the more highly optioned/equipped cars were fitted with an AGM due to the additional load on the battery.

[arkie6]

Note that an Absorbed Glass Mat (AGM) battery is a lead-acid battery. It just has acid suspended in the fiberglass mats between the lead plates. And it has a sealed case with pressure relief valves intended to limit release of gas/vapors. AGM type batteries are also sometimes referred to as Valve Regulated Lead Acid (VRLA) batteries and they are also referred to as non-spillable batteries. This is in contrast with a conventional flooded lead-acid battery that freely vents gas/vapors. AGM batteries typically also have a slightly higher specific-gravity electrolyte (stronger acid) which generally requires a slightly higher float voltage to maintain the cells fully charged. This higher specific gravity electrolyte also provides the extra fuel for higher capacity for a given size battery.

[Sayek]

Looking for some feedback here guys
My 8 year old battery is giving signs on it last legs. At times the battery sign appears on dash so not sure how long i have left.

The car is fitted with AGM. I have seen the same Varta 80AH AGM for for £150. But similar spec acid battery can be picked up for £80.

Is there any advantage of fitting an AGM.. Will it last twice as long as the Acid battery.
I read that AGM are good for Stop/Start but i have disabled that function.

I dont have any issues with the coding as the BMW Carly app allows the switch.

Thanks in advance.