29th Jan 2017, 02:11

Well his car was two years old. An original battery should last at least 7-8 years.

29th Jan 2017, 13:44

Anybody that goes longer than 5 years with a battery is rolling the dice with massive inconvenience. Batteries can fail at any time beyond that. Why be out in the middle of the night or have to call for a jump or tow? Going for 6 or more years is not a good move in my opinion. Especially if you can afford a new BMW. I change mine out, even if they show good. In many cases, doing it at home with all the tools present also saves an install fee. And you can shop around vs paying AAA or the like paying full list price. If it's night or foul weather, perhaps you may appreciate this advice vs the alternative.

29th Jan 2017, 14:17

I also consider 5 years as the safe lifetime of a battery. Anything beyond that is a gamble.

There are electronic testers for the state of health of a battery.

When my battery was 5 years old, I went to a guy who tested it and he said that its days were numbered.

I bought a new battery the next day in order to avoid any risks.

29th Jan 2017, 18:19

Buy a 3 AMP battery maintainer for 30.00, which is not a charger. It kicks on and off as the battery dips. A charger goes constant and will cause your battery to fail if left on all the time. Sears has them. It's a very small box with red, yellow and green lights. I fed a charger wire through my grille on all my cars. Add an inline fuse holder. In less than a half hour it was done. I have it on all my cars, boat and tractor. Roll in, plug in in and your battery is always 100%. Walk out, unplug at the grille and take off. The 5 year change out idea is simple. Pay 100.00 for a typical new battery. Costs you only 20 bucks a year - do the math. If you break down year 6 plus, is it worth it to save so little bucks.

30th Jan 2017, 11:03

I also ran my maintainer wire at the rear of the front hood to the side of my wipers. You never see it. You pull it up when needed. The black wire has an attached rubber cap to keep the weather out. You can lift the hood up and use the clamps provided, but that is a pain. The kit includes a few ways to run it. You can plug into the lighter to maintain the battery, but I do not like backfeeding to the battery. A hard wire is the best. It's very simple to loosen the battery clamps and attach the wires. I even wrote on an index card that the wire is attached and lay it over my speedometer when parked. So I don't drive off with it attached. If you see the maintainer lights staying in yellow and not turning green, you know your battery is almost shot. There are other battery life killers like high heat, extreme cold, many devices drawing high amperage. Our Hondas rarely lasted more than 3 years. Between engine heat and having small batteries (my guess to fit under the hood). The other killer is letting a battery go dead such as leaving an accessory dome light on by accident all night. You can charge back up, but the battery is weakened. A boat can endure this with marine deep discharge batteries. But vehicles demands and temperature extremes take a toll on batteries. The maintainer is a cheap investment. You always have a fully charged battery. You can buy larger versions and use multiple wires inside your garage. I like the singles and use them outside. You have to put the maintainer under a cover out of direct rain. I lay mine in top of my tire inside the wheel well. They are weather resistant with a plastic case, but not totally weatherproof. It takes seconds to hook and unhook at home.

4th Jan 2018, 23:03

This is a classic example of a bad(dirty) battery terminal connection.

Simple.

But with this specific issue it's easy to imagine gremlins everywhere. Especially when there is money to be made by mechanics (oh wait... it's a BMW... so they must be called "techs") pointing in other directions. When they know very well how simple the fix is.

5th Jan 2018, 01:25

There are so many cars out there that run 10-12 years on the original battery, and yet there is always someone who knows better. Surely the kind of person who'd change a synthetic oil after only 3000 mikes because he wants the engine to run for 1000000 miles.

5th Jan 2018, 10:45

My original BMW battery (on a 2001 316TI) lasted 12 years, didn't give any warning like longer starting cranks, before suddenly dying one fateful morning when I tried to start the car, and there was absolutely nothing - not a flicker of even the warning lights, like the battery was stolen. Surprised me how long it lasted, as most batteries I had only lasted maybe maximum of 5 years.

8th Jan 2018, 04:05

This is useful to know. So it appears the battery life is the most affected by heat, in particular in very hot climates and for the cars with the battery mounted inside the engine bay (other cars have the battery inside the trunk). Good to know, even though only 12 months seems quite a bit short, perhaps not the best brand quality. I can report that in cold climates, you can easily expect 8+ years out of the original battery. So it seems it depends on whether the weather is very hot (short battery life, 5 years or so) or temperate (8-12 years of battery life).

8th Jan 2018, 12:39

I do my own every 4 years. And even use battery maintainers. Why? It’s not worth the 10 bucks savings a year keeping the old one. Likely failing at night, bad weather, like rain or snow. Or missing an appointment. Last, you are likely away from home and have the tow or paying more for an install. Not all batteries jump. I watch for a battery sale and do it in my garage. With a cold beer. 15 minutes and good for another 4 years. Cheap piece of mind. Keep a $100 battery 10(!) years. How much is your time worth?

9th Jan 2018, 03:04

I live in So. Florida where the weather is hot pretty much year round. IMO original equipment brand replacement batteries seem to last longer. 11 years ago I bought a used Town Car that I still own today; in 2009 I had to replace the battery which was a Motorcraft replacement, and I saw that it dated back to 2001. Ever since then I have used the Interstate brand and have gone through three of them, averaging about 3 years a piece. Another example was my dad's old 2003 Park Avenue bought new; the original Delco failed 9 years later.

12th Jan 2018, 19:39

But why throw away an item that is still good? A battery is easily tested for health, so you don't throw away something that will last another 4 years. A cheap brand may not even last 3 years while a good brand may last 10 years. If you buy the cheapest on the market, it's OK to replace it after 4 years, but if you buy a good brand, replacing it at 4 years is like throwing money by the window.

19th Jan 2020, 18:17

There are so many myths about how long a battery should last. Those who are located inside the engine bay will last less because of the engine heat; those located inside the trunk last longer. A good quality battery located inside the trunk will last up to 15 years - except if the car is driven short distances or is located in very hot regions. Also, what kills a battery real quick is a poor alternator or a parasitic current draw - if there is a short somewhere, when the car is parked overnight the battery will get discharged even just a little - say down to 80% - then next day while driving it's getting charged back again. Charging and discharging a car battery like this will kill it in a matter of months - even a new battery won't last past the year.