One of our most commonly asked questions is……
Well, what battery do we need fitted?
There’s typically 2-3 choices for normal vehicles. Is it a conventional battery (lead acid) or an AGM (absorbed glass mat) battery? Seldom does our client know the answer & often we don’t either as particularly on BMW’s there is often no rhyme or reason for fitment of which style battery at the factory. Typically as the car has more features, which by the way means more modules (which are just more computers). These require more electrical power current to support, thus more amp hours are required for your replacement battery. So higher spec’d vehicles (more features, higher end models) typically require AGM batteries to carry the load.
An AGM battery is a high capacity battery capable of supporting this additional load. Think of it as a modern version of a deep cycle battery which are commonly used in RV or marine applications.
OK so I have an AGM Battery, so how much?
Now that said, if you have an AGM battery which style of AGM is it? H6, H7, H8 or the elusive H9? They are all a bit different in size and amp hour rating. AGM batteries are not only rated in cold cranking amps, but an amp-per-hour rating which is its reserve capacity or its ability to maintain a continuous current level for a specified time. Think of it as a garden hose vs. a firehose. One can maintain a much more significant volume for a much longer period of time. If the incorrect battery is fitted, it can allow both current & voltage to fall below minimum required which will result in damage to modules, loss of coding or programming of said module. Or quite possibly charging system failure.
Yes, modern BMW’s require a process called battery registration. Why? They have an advanced charging system that is controlled by the engine control module (DME for you techies). He’s the theory behind it.
As a battery ages, the plates will sulfate. Think of it as hard water deposits on your sink faucet. This coats the plates and in turn makes it harder for the battery to accept the charge from the alternator. The result is shorter battery life & lowered performance as it ages. The solution BMW has come up with is achieved by the registration process. Through the use of ISTA (BMW factory scan tool) we are able to effectively reset module. Telling the module a new battery is now fitted, charge it as such. Now as battery ages, it will monitor both current from alternator & retained voltage within the battery. Retained voltage will begin to dip slightly as battery ages. When the module see’s this behavior it will increase alternator output, bringing it back to specified voltage. This keeps battery to peak performance & extendeds its life.
Now had you had your cousin, you know the one with a driveway full of cars that don’t run. Fit a battery, without first verifying that replacement was required. Further not registering it. Or worse yet not correctly torquing connections at intelligent battery sensor (IBS). Here’s what will happen. The module will continue to pump an elevated charge rate at this brand new battery that has no sulfation on it’s plates so it really takes the charge. Which increases the temperature of the battery, resulting in off gassing. Yes even on an AGM. It will in a few short weeks or months if you’re really lucky. The battery will boil itself dry. Best case your vehicle just won’t start. Worst case it can damage modules. All that said It’s not just a matter of going to local parts store & fitting it yourself in the parking lot. And no batteries don’t cost $69 anymore. Not even for a motorcycle. I believe a lot of it is the cost to ship, but mostly the fact that batteries are doing twice or more the work they once did. Your basic vehicle (read 1986 Buick) requires sufficient current for lighting, radio, ignition system. Todays cars need all that and current for more than 50 modules. Think of it as running 50 laptops all the time. No small task. It is imperative that the modules have clean consistent power.
If you’re still with me and feeling a little frustrated; we get it! We have this conversation with our clients constantly.
So that’s why we’ve done it. That is flat rate battery pricing. We have all the possibilities on the shelf & we’ll determine what is correct for you particular application.
So here’s the break down;
AGM battery fitted. $352** + tax & disposal fee(s). Vehicles that have batteries in particularly difficult location to get to. That is most ML’s, GL’s & some x5’s have a slightly elevated labor charge. This includes charging system analysis, battery registration, teach in process for windows, sunroof(s) cabrio tops, etc. These batteries carry a 30-36 month warranty depending on specific model fitted.
**Cannot be combined w/ any other offers
Lead acid battery fitted. $297** + tax & disposal fee(s). Again vehicles that have batteries in particularly difficult location to get to. That is most ML’s, GL’s & some x5’s have a slightly elevated labor charge. This includes charging system analysis, battery registration, teach in process for windows, sunroof(s) cabrio tops, etc. These batteries carry a 24-36 month warranty depending on specific model fitted.
**Cannot be combined w/ any other offers