[vooonoo]

Was just doing a few things on the car and i noticed that my battery's build date is 30/13 so the 30th week of 2013. I threw a trickle charger on it on the jack points under the hood after noticing the date.

Just wondering since my battery is 5 years old... that's about how long normal car batteries last (~4-6 years). I haven't had any issues.

Just wondering how long your guy's batteries have lasted?

[HighlandPete]

6 years 8 months, so far.... I do use a CTEK charger several times each winter, to keep a decent state of charge.

[chiefneil]

Here in Phoenix car batteries typically last around 3-4 years. With the 3 other bimmers we bought since moving to AZ we always had one battery replacement under warranty, so within 4 years. My F30 335i is about 5 months out of warranty and still on the original battery, so it’s a bit of an anomaly but also the first that’s only driven a few times a week vs the others that were daily drivers. I’ll probably do a preventative replacement in a couple months before summer hits.

Anyway, that’s my long-winded way of saying that weather (heat in particular) and usage do factor in to the life of a battery but 3-6 years in general sounds about right.

[bavarianride]

My last bimmer's OEM battery last 8+ years in California weather.

[tex2670]

Originally Posted by vooonoo

Was just doing a few things on the car and i noticed that my battery's build date is 30/13 so the 30th week of 2013. I threw a trickle charger on it on the jack points under the hood after noticing the date.

Just wondering since my battery is 5 years old... that's about how long normal car batteries last (~4-6 years). I haven't had any issues.

Just wondering how long your guy's batteries have lasted?

Mine's 3 days old. I have a '14, which was in for service this week, and a rough idle when cold. Dealer said battery needed replacement, and actually did it under warranty (43,300 mi).

Next time you have your car serviced, I'd have them run a battery test. Getting stuck with a dead battery is rarely fun.

[bimmer456]

I would think AGM batteries and the fact that these are higher output than what you might see in a Ford or Honda and the fact they are trunk mounted should allow them to last longer, so not surprised by the longer life of 8+ years, though there seems to be some variation from people on here. Mine is still strong after 2 years while the flooded cell batteries in my other car often only last 2 years so I get them replaced under warranty. The latest flooded cell battery I've been using the BMW battery tender every couple of weeks and it has made it past the 2 year mark, about 2 years and 4 months still going strong.

[jparnes1]

Check the battery with a volt meter in the morning after it's had a chance to discharge over night. Don't start the engine. You should read 12V or over. Anything less, get a new battery. Weird electrical things happen when the battery is weak.

[adhrp]

Car manufactured in Dec 2011, so 6 yrs and 3 months old and going strong.

Edit: corrected a basic arithmetic error.

[bavarianride]

Originally Posted by adhrp

Car manufactured in Dec 2011, so 7 yrs and 3 months old and going strong.

That would be 6 yeas and 3 months.

[RoundelM3]

5 years as of this past January...zero problems.

[Billfitz]

6 to 8 years if you use a maintainer when it's cold, or if you live where it doesn't get cold.

[evdok]

mines 4.5 years old and currently on 78%, only do 5k a year so not bad considering.

[cfm56d7b]

Originally Posted by bavarianride

My last bimmer's OEM battery last 8+ years in California weather.

This is very encouraging.

[adhrp]

Originally Posted by bavarianride

That would be 6 yeas and 3 months.

Oh haha, yes! Thanks for catching that. Time for me to go back to grade school

[Dirk Diggler]

Originally Posted by evdok

mines 4.5 years old and currently on 78%, only do 5k a year so not bad considering.

What do you mean "currently on 78%"? Do you have a way of knowing your battery's health or something?

[HighlandPete]

Originally Posted by Dirk Diggler

What do you mean "currently on 78%"? Do you have a way of knowing your battery's health or something?

Probably referring to SOC, (state of charge). If so, Energy Management runs the AGM batteries ~80% SOC. Allows for over-run (regeneration) charging.

[evdok]

A friend connected the battery to a reader & checked the condition.

[JJS]

My original battery is 4 months shy of its 5th birthday. My experience with ordinary lead-acid batteries is that they die suddenly; but I can't be sure about AGM types. But I've now noticed that when I (rarely) have ASS in action, the engine restarts much more quickly than it used to. I suspect my battery may be on its way out. The longest I've ever had a lead-acid battery last was 7 years, but most have been between 3-4 years.

I'll hook my battery up to a diagnostic charger and see if I should get it replaced at its next service due in about 2,500km.

[VCuomo]

Mine's the original from the factory, it's a little over 6 years old.

[m_paltik]

Mine is 05/13 production date but I'm the second owner. I bought it CPO. I'd be happy to get another year out of the battery. That voltage drop to 12.35V when it sits overnight.

I live in Nevada and lead acid battery usually last 2-3 years because of the heat and the battery mounted inside the hood isn't helping.

[JJS]

Overnight, my battery measures just on 12.5V. Hooked up to my AGM diagnostic charger, it seemed to indicate 75% charge. It should be closer to 12.8V on a full charge. Anyhow, I let it charge overnight and I will measure it again after a few days of normal use.

[HighlandPete]

Originally Posted by JJS

Overnight, my battery measures just on 12.5V. Hooked up to my AGM diagnostic charger, it seemed to indicate 75% charge. It should be closer to 12.8V on a full charge. Anyhow, I let it charge overnight and I will measure it again after a few days of normal use.

BMW's energy management doesn't run at 100% SOC. Works at about 80%.

If we charge to 100% SOC, after a few days use it will drop back, as the energy management doesn't charge the battery. Leaves capacity for the over-run regeneration. If we don't drive a profile that gets much 'regeneration/harvesting' it is likely it will settle around 80% in normal use. 75 - 80% SOC is not necessarily a sign the battery is on the way out.