So I Had to Replace My Battery!

[Happy Jose]

The yellow battery icon light kept showing up when I put a light load on the car's electrical system, like using a scanner. I checked the battery's age, and it was 3 months short of being 7 years old. I didn't think it was a senior citizen yet, since I can usually get 10 to 11 years out of a battery.

I decided to replace it with an AGM battery from Advanced Auto Parts:

Autocraft Platinum H6-AGM
CCA 760
CA 950
AH 70
RC 170
Core $22
$138.34 including tax

The OEM battery was a flood battery, so I had to first have the battery coded and then registered. If the replacement had been identical to the OEM, I could have just registered in with my Icarsoft Multi-system Scanner BMM V2.0 for BMW/MINI.

For the heck of it, I decided to check out the registration functions to see if it worked. Indeed it did. BTW, the purpose of registration is to notify the DME that a new OEM battery is installed which doesn't need to be charged as aggressively as an older battery.

Anyway, I took the car to an independent to have it coded and registered. This cost a hundred bucks, rats! Interestingly, the idle was slightly lower for the new battery than the old.

If you want to be sure you need a new battery, perform a load test:

[Mr Gasser]

so if your battery is weak, you get a yellow dash icon? good to know!

[ejm3]

I asked this question after my water pump failure left me high and dry and in need of a tow.

I have a 2012 and never replaced the battery so I know its coming and didn't want to be stranded on the side of the road somewhere.

SA laughed and said I would get a yellow warning light beforehand the battery is dead so I shouldn't have that problem.

[Matticus91]

Look at this post, it's always worth searching before you dump a bunch of money on something: http://www.1addicts.com/forums/showt...=battery+carly

[captain slowly]

when the battery went in my car, there was no yellow warning, ever. It just started cranking slower over the course of a few weeks, and eventually wouldn't start at all.

RootyTootyFruity, if you start getting weird electrical issues here and there, know its because the correct battery isn't installed. Hope it works out.

[Zombie_Head]

Originally Posted by Mr Gasser

so if your battery is weak, you get a yellow dash icon? good to know!

When i test drove my car from the previous owner, there was a dash icon "low charge" indicated.

After a 15-20 minute drive, we restarted the car and the warning never showed up. The previous owner rarely drove the car, he totalled 3,000 kms in 2 years of ownership, so i thought the battery was just sitting being drained and not allowed to get charged correctly.

After owning the car i never saw any warnings and no signs of a bad battery for 5 weeks. Then, as we saw -12c winter and lower, cranking started to start funny.

So i bit the bullet and replaced it with the same exact unit, for it for €103 from the dealer and coded it myself with carly app.

[04mazdaspeed]

Originally Posted by Happy Jose

The yellow battery icon light kept showing up when I put a light load on the car's electrical system, like using a scanner. I checked the battery's age, and it was 3 months short of being 7 years old. I didn't think it was a senior citizen yet, since I can usually get 10 to 11 years out of a battery.

I decided to replace it with an AGM battery from Advanced Auto Parts:

Autocraft Platinum H6-AGM
CCA 760
CA 950
AH 70
RC 170
Core $22
$138.34 including tax

The OEM battery was a flood battery, so I had to first have the battery coded and then registered. If the replacement had been identical to the OEM, I could have just registered in with my Icarsoft Multi-system Scanner BMM V2.0 for BMW/MINI.

For the heck of it, I decided to check out the registration functions to see if it worked. Indeed it did. BTW, the purpose of registration is to notify the DME that a new OEM battery is installed which doesn't need to be charged as aggressively as an older battery.

Anyway, I took the car to an independent to have it coded and registered. This cost a hundred bucks, rats! Interestingly, the idle was slightly lower for the new battery than the old.

If you want to be sure you need a new battery, perform a load test:

I just looked up the battery on advance and its 199.99? How did you get it for less?

[Happy Jose]

Originally Posted by 04mazdaspeed

I just looked up the battery on advance and its 199.99? How did you get it for less?

They have sales on everything. I believe I got a 25% or better discount. Anyway, it's a matter of timing.

[icegrill]

Did you smell it to know it was time for a new battery?

[Moooshay]

Week 2 of ownership. Had to drive through light rain coming back from a trip and picked up debris on the rocker panels and decided to run to a wand wash at lunch to get the debris off. Pulled into the bay and it turns out the bay was out of service. Got back in, and nothing but a couple clicks. Dead battery, now I have a AAA battery that I need to go get coded. /sigh.

[jlc45]

The 135I and maybe other models have a complicated battery usage/charging system.
Maybe someone can correct this if I don't have this perfect but roughly here is how it works. The charging system does not attempt to keep the battery fully charged at all times. It lets the battery partially "run down" if the system is all good and the car is driving well. I guess this saves wear and tear on the charging system and saves a tiny bit on gas mileage. In effect, the car's electrical load is running off the battery at times. Once the battery charge level gets "too low" then the charging system (alternator) runs and charges it back up close to max. charge. It keeps cycling like this until eventually the battery can't operate under this routine as it gets old (sulphated?)
My car was operating more or less normally but when I put a battery minder on it (12V, 1.25a) it took about an hour to bring it up the actual full charge. FYI, I have left the car on three different occasions (once was 1 month, once was 2 months, and once was 4 months) without any battery charger accessory, and the car started right up for me every time! But now I have bought a trickle charger ($72) for the coming winter so even though I didn't have a problem (to my knowledge), I'm not pushing my luck any further.

[Zombie_Head]

Originally Posted by Mr Gasser

so if your battery is weak, you get a yellow dash icon? good to know!

When i first saw the 125i for sale, on start up the battery light (yellow) came on.

After a 30 minutes test drive and restarted the car, the light never came back on.

About 4-5 weeks after purchase during cold starts every morning, the car would struggle cranking, and no lights were coming on. It was evident that the battery was weak, got a new one from dealership for €120 and they took my old one.

Weak/bad batteries are weird sometimes, lights come on or off or just clearly weak cranks.

[JimD]

BMWs do weird things from low voltage. My wife's 128i battery failed, it developed a very weak connection between plates inside the battery, at less than 4 years old. A AAA tow truck jumped it at the battery and I jumped it under the hood and we got it started. But the wipers came on and the dash was all lit up. It settled down a bit and she drove it straight to the dealer and paid for an expensive battery replacement. But before it died, it gave no signs.

My battery is now 9+ and I get an occasional battery symbol but it came on and stayed on a few months ago on the way to work. I thought it was the battery but it was really the alternator. When I went less than 10 miles, the car started to light up all the warnings on the dash and then started the windshield wipers (which my wife's car did too). I think these antics are programmed into the car by the same dim witted engineers who gave us an inaccurate, cannot be code fixed, speedometer.

So I believe after these experiences that the battery symbol can mean a weak battery but it can also mean your alternator has failed. If it is the latter, the voltage stays low and the symbol stays on. If the voltage goes down further, the car starts freaking out. That programming is not my favorite feature of the cars.

[Olgeezer1]

Originally Posted by jlc45

The 135I and maybe other models have a complicated battery usage/charging system.
Maybe someone can correct this if I don't have this perfect but roughly here is how it works. The charging system does not attempt to keep the battery fully charged at all times. It lets the battery partially "run down" if the system is all good and the car is driving well. I guess this saves wear and tear on the charging system and saves a tiny bit on gas mileage. In effect, the car's electrical load is running off the battery at times. Once the battery charge level gets "too low" then the charging system (alternator) runs and charges it back up close to max. charge. It keeps cycling like this until eventually the battery can't operate under this routine as it gets old (sulphated?)
My car was operating more or less normally but when I put a battery minder on it (12V, 1.25a) it took about an hour to bring it up the actual full charge. FYI, I have left the car on three different occasions (once was 1 month, once was 2 months, and once was 4 months) without any battery charger accessory, and the car started right up for me every time! But now I have bought a trickle charger ($72) for the coming winter so even though I didn't have a problem (to my knowledge), I'm not pushing my luck any further.

Hopefully you mean "smart charger", not "trickle charger" as the latter will result in overcharge. The smart chargers from BMW, Deltran, C-tek are what you want.

[Gangplank]

Originally Posted by Olgeezer1

Hopefully you mean "smart charger", not "trickle charger" as the latter will result in overcharge. The smart chargers from BMW, Deltran, C-tek are what you want.

Or a $25 black & Decker. I got one at Home Depot, works just fine

[jlc45]

Yes, I bought the so-called smart charger from BMW dealer. It has an official BMW sticker on it! Interestingly, it indicates that my battery is not fully charged after normal driving. But I guess the charger is only "adding" 1.25 amp-hours of energy every hour since it applies 1.25 amps of current to the battery terminals, which isn't very much relative to the total capacity of the battery.

I=Q/t Q=It Charge (in amp-hours) = current (in amps) x time (in hours)

[Happy Jose]

Trickle, maintenance, or smart chargers generally mean the charger will bring the battery up to its full or 100% electrical capacity and keep it there. My C-Tex chargers do a marvelous job of maintaining the batteries in my BMW and Benz. In fact, they are so good they'll bring a totally dead battery back to life within 24 hours.

Anyway, I keep my cars in a garage, and I hookup the C-Tecs even for short periods of time. Cold weather can deplete an older battery over a weekend of sitting unused.

BTW, the yellow battery symbol refers to the battery while red to the alternator.

[________]

Originally Posted by Happy Jose

Cold weather can deplete an older battery over a weekend of sitting unused.

BTW, the yellow battery symbol refers to the battery while red to the alternator.

If your battery depletes in a weekend or even in 1 week, your battery needs to be replaced.

Cheers

[ultimated]

Originally Posted by Matticus91

Look at this post, it's always worth searching before you dump a bunch of money on something: http://www.1addicts.com/forums/showt...=battery+carly

Thanks for the link; I installed the new battery today and registered it with Carly, but a yellow warning light saying the adaptive steering was initializing came on. No error codes came up when I ran the Carly diagnostic again. Any ideas? Disconnect battery for overnight and try again?

[JimVonBaden]

I had mine done on Friday. Pep Boys installed a Bosch Premium, coded it and out the door for $185.

[Matticus91]

Originally Posted by ultimated

Thanks for the link; I installed the new battery today and registered it with Carly, but a yellow warning light saying the adaptive steering was initializing came on. No error codes came up when I ran the Carly diagnostic again. Any ideas? Disconnect battery for overnight and try again?

Doubt it's related, did the light go away?

Originally Posted by JimVonBaden

I had mine done on Friday. Pep Boys installed a Bosch Premium, coded it and out the door for $185.

That's insanely cheap! Did they have a deal running? The local PB quoted me way more when I was calling around.

[gjm120]

Originally Posted by JimVonBaden

I had mine done on Friday. Pep Boys installed a Bosch Premium, coded it and out the door for $185.

Are you sure they coded it? I'd be surprised if they could do coding. Registering is easy with most any good scan tool.