Main Battery Replacement
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Joined: Aug 2011
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From: Highlands Ranch, Colorado
2014 BMW M235i
Main Battery Replacement
I had my battery load tested at the dealership and they said everything was fine with the main battery, so I am good for a few more years but just so I have this information ahead of time, how much should I expect to pay for a W211 main battery change?
I ask this because out of curiosity I was searching the forums and there were figures mentioned for the pre-facelift that also had an auxiliary battery quoted at around $350-450 for both, installed. They also mentioned the battery should be an AGM battery, for the pre-facelift at least, and that these were usually more expensive (most said something about either a Bosch or Optima brand name). In the manual it says "depending on the production date" the battery is a VRLA battery. When I was at the dealership the service adviser mentioned that my car has "newer style of battery that does not need to be replaced/updated"... does this mean a VRLA or an AGM?
Finally, if the car ever loses power do I have to do any special code entry or computer reset?
Thanks.
EDIT: Upon further research I found that VRLA batteries can actually be classified as AGM or Gel batteries. Is this the most current battery technology you see in high-end cars (obviously not hybrids) in this segment? Is this the older "style" you think the dealer was mentioning?
I ask this because out of curiosity I was searching the forums and there were figures mentioned for the pre-facelift that also had an auxiliary battery quoted at around $350-450 for both, installed. They also mentioned the battery should be an AGM battery, for the pre-facelift at least, and that these were usually more expensive (most said something about either a Bosch or Optima brand name). In the manual it says "depending on the production date" the battery is a VRLA battery. When I was at the dealership the service adviser mentioned that my car has "newer style of battery that does not need to be replaced/updated"... does this mean a VRLA or an AGM?
Finally, if the car ever loses power do I have to do any special code entry or computer reset?
Thanks.
EDIT: Upon further research I found that VRLA batteries can actually be classified as AGM or Gel batteries. Is this the most current battery technology you see in high-end cars (obviously not hybrids) in this segment? Is this the older "style" you think the dealer was mentioning?
Last edited by AMGAffalterbach; Sep 3, 2013 at 01:27 AM.
I replaced both batteries earlier this year, I just went to Wal-Mart and bought two batteries from them and swapped them out. Nothing needed to be re-synced or entered in. I just made sure to replace each individually so there's always power to the computer systems.
replaced both of my batteries from advance auto. As far as resynching, its easy.
Windows, lift up on the control until you hear a click, hold for 3 seconds. Do for each window control.
Sunroof, pull down until you get a click, should automatically open the cover just like before.
Windows, lift up on the control until you hear a click, hold for 3 seconds. Do for each window control.
Sunroof, pull down until you get a click, should automatically open the cover just like before.
From the CarsDirect website : (http://www.carsdirect.com/car-mainte...s-and-cons-faq)
ie...go AGM.
VRLA/Gel--You will have to charge them at a slower rate to prevent excess gas from forming and collecting inside the battery. They cannot be fast charged on automotive chargers due to this problem. They also have to be charged at a lower voltage (2/10ths less) than ordinary batteries. Overcharging will cause the gel to become permanently porous. This will affect the life of the battery and will cause a loss in power.
Is There a Better Variety of the Gelled Battery?
In hot weather, the gelled battery can lose water resulting in permanent damage. "Absorbed Glass Mats" or AGM between the plates is a far better variety that you can use now.
Is There a Better Variety of the Gelled Battery?
In hot weather, the gelled battery can lose water resulting in permanent damage. "Absorbed Glass Mats" or AGM between the plates is a far better variety that you can use now.
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You're welcome. It's also noteworthy to mention that when reconnecting the main battery, turn on some electricals first.
I disconnected my main battery for about an hour ( I forget why) without doing that. When reconnected, I lost all of my Keyless Go functions.
That was a year ago.
I disconnected my main battery for about an hour ( I forget why) without doing that. When reconnected, I lost all of my Keyless Go functions.
That was a year ago.








