Battery Options Revisited?

[FogCityM3]

Know there have been prior posts about lighter weight battery options (Braille) and MINI/CSL, but from prior posts both options seem to be problematic due to low amp-hours (55 or lower). I have noticed that the M3 GT4 (motorsport car) and a few other BMW OEM batteries (for several 5 series) gave almost same power as the stock M3 battery, are lighter and seem to be cheaper on various internet parts lists. While 12-15 lbs is nothing in terms of any perceivable weight loss, was thinking that when my battery needs to be replaced (typically 4 years), why not go for a cheaper option with lighter weight, especially in warmer climates (think these other battery options have lower CCA lowest at mid 600s ratings vs original 900, but may not be as much of an issue in warmer climates).

Does anyone know/have experience with the following battery options /part numbers and whether would fit in existing battery cradle/bracket?.

Original Battery: 6121 6924023 90 Ah (57.6 lbs)
GT4 Battery: 6121 8376451 80Ah (45.7 lbs) – most likely fits with no mods?

Other part number options for 9x/5x series
6121 8381786 90 Ah (52.6 lbs)
6121 7555719 80 Ah (41.6 lbs)
6121 8381730 70 Ah (41.2 lbs)

[THE TECH]

Originally Posted by mhabs

Know there have been prior posts about lighter weight battery options (Braille) and MINI/CSL, but from prior posts both options seem to be problematic due to low amp-hours (55 or lower). I have noticed that the M3 GT4 (motorsport car) and a few other BMW OEM batteries (for several 5 series) gave almost same power as the stock M3 battery, are lighter and seem to be cheaper on various internet parts lists. While 12-15 lbs is nothing in terms of any perceivable weight loss, was thinking that when my battery needs to be replaced (typically 4 years), why not go for a cheaper option with lighter weight, especially in warmer climates (think these other battery options have lower CCA lowest at mid 600s ratings vs original 900, but may not be as much of an issue in warmer climates).

Does anyone know/have experience with the following battery options /part numbers and whether would fit in existing battery cradle/bracket?.

Original Battery: 6121 6924023 90 Ah (57.6 lbs)
GT4 Battery: 6121 8376451 80Ah (45.7 lbs) – most likely fits with no mods?

Other part number options for 9x/5x series
6121 8381786 90 Ah (52.6 lbs)
6121 7555719 80 Ah (41.6 lbs)
6121 8381730 70 Ah (41.2 lbs)

People have been using the batteries from other BMWs with success. I don't see the real reason to though.

[Grail05]

They should but if you have Idrive or other electronics i suggest stick with whatever you got..

idrive cars recommended at least 70ah... but thats if you dont have any other electronics stuff running.

below that non idrve cars

I recently purchase a battery from Sears.. heres the reason why..

1. warranty is 3 years
2. i dont drive that often 7 miles everyday
3. sears will honor warranty no matter how you drive unlike BMW if you dont drive enough they will not replace the battery..

SPECS on sears battery

AGM 49 battery
850cca
92ah..

[kawchkjf]

Maybe BPM can chime in and explain why a battery needs to be coded to the vehicle as well?

I'm guessing a Sears AGM won't be able to be coded...?

[mdefalco25]

The battery needs to be coded so the car draws the proper amps from the new battery and doesn't try to overcharge it. At least that's my breakdown of it. While you can go w/o coding (not recommended) it is widely stated this will reduce the life of your battery.

[nmehta211]

Originally Posted by Sean05

They should but if you have Idrive or other electronics i suggest stick with whatever you got..

idrive cars recommended at least 70ah... but thats if you dont have any other electronics stuff running.

below that non idrve cars

I recently purchase a battery from Sears.. heres the reason why..

1. warranty is 3 years
2. i dont drive that often 7 miles everyday
3. sears will honor warranty no matter how you drive unlike BMW if you dont drive enough they will not replace the battery..

SPECS on sears battery

AGM 49 battery
850cca
92ah..

My thoughts exactly. I had my Sears battery installed today, it was half the price of the lowest quote on an OEM battery, and some dealers told me that if the battery wasn't installed at the dealership, it would have no warranty at all!

[nmehta211]

Originally Posted by kawchkjf

Maybe BPM can chime in and explain why a battery needs to be coded to the vehicle as well?

I'm guessing a Sears AGM won't be able to be coded...?

Sears battery (or any comparable battery) can be coded.

[tom @ eas]

Originally Posted by kawchkjf

Maybe BPM can chime in and explain why a battery needs to be coded to the vehicle as well?

I'm guessing a Sears AGM won't be able to be coded...?

The battery itself isn't coded, the vehicle is coded to accept the new battery.

Originally Posted by tom @ eas

Absorbent Glass Matt Battery (AGM)

In contrast to conventional lead-calcium batteries, the sulfuric acid in an AGM battery is not held freely in the battery housing. The sulfuric acid is instead entirely bound into the mats of the glass-fiber fleece. For this reason , no acid can escape if the battery housing is damaged. In addition, the AGM battery is a sealed, airtight unit. This is possible because the gasses are converted back into water by the permeability of the separators.

Construction
AGM batteries differ from conventional lead-calcium batteries in the following points:

- Larger plates which allow a power density some 25% greater
- Glass-fiber-fleece separators which enable a cycle consistency up to 3x greater improving cold-starting ability, current consumption and service life
- Airtight housing with pressure relief valve
- Inspection plugs sealed and cannot be opened
- Acid bound in glass-fiber fleece

How AGM Batteries Work
AGM batteries differ from conventional lead-calcium batteries in their environmental compatibility and their retention of gases during charging. When a vehicle battery is charged, the electrolysis process emits the gases oxygen and hydrogen . In a conventional lead-calcium battery, these two gases are released into the atmosphere. In an AGM battery, the two gases are converted back into water: The oxygen created at the positive electrode during charging moves through the permeable glass-fiber fleece to the negative electrode, where it reacts with the hydrogen ions that are brought in with the electrolyte, to create water (oxygen cycle). In this manner, the gases, and thus the electrolyte, is not lost.

Only when the gas production is excessive, that is when too much pressure is generated (20 to 200 mbar), does the pressure-relief valve open, thereby allowing gas to escape while also preventing entry of atmospheric oxygen. Because the pressure in the battery is regulated by a valve, the AGM battery is also known as the VRLA battery (valve regulated lead acid).

Service Instructions for AGM Batteries
When handling AGM batteries, certain special factors must be taken into consideration with regard to battery renewal and installation location:

Do not charge AGM batteries with 14.8 volts or use use rapid charging programs
When charging batteries in the "stand alone" mode, the maximum charge voltage of 14.8 volts must not be exceeded. Even briefly charging an AGM battery with a charge voltage of more than 14.8 volts (voltages usually used in rapid charge programs) will damage the battery

Do not install AGM batteries in the engine compartment
Because of large temperature variations, AGM batteries must not be installed in the engine compartment. This would result in a significant reduction in the service life of the battery

Do not open AGM batteries
By no account should AGM batteries ever be opened, as oxygen from the atmosphere would cause the battery to lose its chemical balance and cause it to fail.

Battery Replacement
An AGM battery, when installed as original equipment, must always be replaced with an AGM battery. In special cases, where a customer's driving profile (e.g. short distance driving), results in a discharged battery, the AGM battery is a recommended replacement.

Note that replacement batteries resulting from a customer's driving profile cannot be claimed under warranty.

Battery Replacement Registration

This Service Function informs the PM that the battery has been replaced. It completes the following operations:

- Battery capacity is set to 80%
- Current Odometer reading are stored. The odometer readings at which the last seven battery replacements took place can be read off from the Diagnosis Requests of Control Unit Functions
- Stored battery statistics (current, voltage , battery charge level) are deleted
- Stored temperature statistics are deleted

Hope this helps.

[thorny]

I run CSL/Mini battery with zero issues. I dont drive daily and it is Californian winter here i got iDrive and every other power hungry acccessory, except upgraded sound system.

It fits like OEM, it is just smaller, so you can use remaining space to store bags of peanuts for example, just in case your battery dies and you get stranded in a wild

[tom @ eas]

Originally Posted by thorny

I run CSL/Mini battery with zero issues. I dont drive daily and it is Californian winter here i got iDrive and every other power hungry acccessory, except upgraded sound system.

It fits like OEM, it is just smaller, so you can use remaining space to store bags of peanuts for example, just in case your battery dies and you get stranded in a wild

Same here, shaves about 30lbs from the stock unit in the process.

[Crypty]

My understanding is the battery is not coded per se. The coding is the reset of an internal timer in the car. The car uses this timer to determine how much to charge the battery. Older batter = more charging.

[Dellort_M3]

Does this coding need to be done for every car receiving a new battery? i.e honda, merc, chevy etc

[Crypty]

Originally Posted by Dellort_M3

Does this coding need to be done for every car receiving a new battery? i.e honda, merc, chevy etc

No. Maybe some cars, but this is definitely a non-standard "feature."(Pain in the ass/price gouge opportunity)

[FogCityM3]

Good to know....was worried in doing it because of auto start/stop, but looks like you also have the feature in your 2011?

Originally Posted by thorny

I run CSL/Mini battery with zero issues. I dont drive daily and it is Californian winter here i got iDrive and every other power hungry acccessory, except upgraded sound system.

It fits like OEM, it is just smaller, so you can use remaining space to store bags of peanuts for example, just in case your battery dies and you get stranded in a wild

[FogCityM3]

Thx tom, do you have the auto start/stop on your car (was worried about this using MINI battery setup)?

Originally Posted by tom @ eas

Same here, shaves about 30lbs from the stock unit in the process.

[apecush]

how does the cost of the mini csl battery compare to the bmw oem one?

[pbonsalb]

Not much difference when I checked. I bought a Mini battery for my 99M3 a couple of years ago for about $145 and I priced an AGM battery for my 08M3 recently for about $160, both at Autozone.

[Grail05]

Originally Posted by apecush

how does the cost of the mini csl battery compare to the bmw oem one?

EAS sells it

[shendrick]

Using batteries with lower AH specs means less wiggle room when the battery needs to be replaced. My 08 was very unforgiving when I got to the point of needing a new battery - to the point where the car was almost undrivable. For the limited weight savings and risk of being stranded down the line - I would stick with the stock BMW battery - coding and all.

[aus]

Is the Optima Yellow or Blue top batteries AGM and compatible with BMW's?

Originally Posted by thorny

I run CSL/Mini battery with zero issues. I dont drive daily and it is Californian winter here i got iDrive and every other power hungry acccessory, except upgraded sound system.

It fits like OEM, it is just smaller, so you can use remaining space to store bags of peanuts for example, just in case your battery dies and you get stranded in a wild

Do you have start/stop? I know these cars have a larger battery.

[thorny]

Originally Posted by aus

Is the Optima Yellow or Blue top batteries AGM and compatible with BMW's?




Do you have start/stop? I know these cars have a larger battery.

I do, but have not tried it yet.

[SHADY1]

Originally Posted by nmehta211

Sears battery (or any comparable battery) can be coded.

Originally Posted by nmehta211

My thoughts exactly. I had my Sears battery installed today, it was half the price of the lowest quote on an OEM battery, and some dealers told me that if the battery wasn't installed at the dealership, it would have no warranty at all!

Sears warranty is better than BMW anyway

Originally Posted by Sean05

They should but if you have Idrive or other electronics i suggest stick with whatever you got..

idrive cars recommended at least 70ah... but thats if you dont have any other electronics stuff running.

below that non idrve cars

I recently purchase a battery from Sears.. heres the reason why..

1. warranty is 3 years
2. i dont drive that often 7 miles everyday
3. sears will honor warranty no matter how you drive unlike BMW if you dont drive enough they will not replace the battery..

SPECS on sears battery

AGM 49 battery
850cca
92ah..

I have a Sears battery now and I am very happy here is my nightmare with the Stealership

I do not daily drive my M3 and I replace my original battery after about 3yrs it went dead in Nov. 2011. I paid 300+ for a new bmw battery plus another 200+ to have it reset the total was almost $600.00 only to have the new battery start going dead again in less than a year Aug 2012. The battery would still hold a charge but if I turned the car off and left anything going such as the radio for 5 min the car would not really want to start. Took it to the Stealership they said the computer says I left the radio on. I was like WTF I don't even daily drive my M3. They charged the battery 100 %. I take a 3 hour road trip sit in the car with it off for 5 min car went dead and needed a jump Called Service Rep he said they are not going to replace under warranty because the car is saying I left the radio on I can either buy a new BMW battery (yeah right another $600.00) or a battery charger. I bought a battery charger since I don't daily drive the car, that still did not really make a difference because the battery would still go dead. If you sit in the car for 5 min or less with anything on . So I did some research on this post about the Sears battery. So I fully charged the BMW battery one last time and I went to Sears and bought a new battery and replaced it. The funny thing is I guess my car did not notice I changed the battery because it never threw a code to reset or anything I called my service rep and told him and he was like but I am happy I had no other problems ever since. I guess since I charged the Old battery just before I changed it, must be the reason the car did not notice the change or anything oh well save me some money from getting it coded at the Stealership sorry for the