Replacing battery - do I need a "keep alive" tool?

[M37owner]

I'm replacing the battery in my 2011 M37.
Am I supposed to use one of those "keep alive tools" (like the kind with a 9V battery that plugs into 12v Acc plug - or something similar to keep power on the car) when I disconnect the battery so that I don't lose anything stored in memory, like programmed radio stations, comfort settings, keyfob link, etc.?

[silberma]

You don't save money by changing the battery yourself. Went to Walmart which has good batteries at excellent prices and they plugged a voltage retainer while changing the battery. Many other places will do it for you for free. No point going the DIY route

[M37owner]

So the answer is " a voltage retainer (keep alive tool) is used.

It's not about saving money. It's about the quality of the work. I will not let anyone else work on my car (if I can help it) unless they are the Dealer and ASE certified (even then I don't like it). Too many shops (especially like Walmarts, PepBoys, Sears, and Quick Change Oil places) don't have real mechanics, they have the HS drop out- minimum wage- employees that haven't a clue as to what quality work is.
Sorry for rambling - don't get me started on this subject.

[Debonair]

You don't save money by changing the battery yourself. Went to Walmart which has good batteries at excellent prices and they plugged a voltage retainer while changing the battery. Many other places will do it for you for free. No point going the DIY route

Personally, the last place I would let touch my car is Walmart. The DIY route gives me the peace of mind that the job was done correctly by someone who has cares.

I never use a "keep alive" tool. I do own one which now that I think of it is pretty funny since I do not use it. I think the only programming I have ever lost is the radio stations.

[Ilya]

I didn't lose anything when I switched mine right in the Sears parking lot (it died at an opportune time lol). At least I don't recall losing anything. If you have the tool, it wouldn't hurt to use it though. If I did lose anything, it wasn't a big deal since I don't remember lol.

[Debonair]

I didn't lose anything when I switched mine right in the Sears parking lot (it died at an opportune time lol). At least I don't recall losing anything. If you have the tool, it wouldn't hurt to use it though. If I did lose anything, it wasn't a big deal since I don't remember lol.

I have had my battery disconnected for long periods of time for various project, so this may be what I am remembering.

[Ilya]

I was referring to the OP...hah

[Debonair]

Fine.

[silberma]

Why do you need a delaer or a certified mechnaic to loosen a battery bracket and disconnect the battery leads. This is not rocket science and any 18 year old (even a HS dropout) should be able to do it without damaging your car.

[Debonair]

Why do you need a delaer or a certified mechnaic to loosen a battery bracket and disconnect the battery leads. This is not rocket science and any 18 year old (even a HS dropout) should be able to do it without damaging your car.

I don't think M3owner said he or anyone NEEDS a dealer or ASE mechanic to change the battery. He said no one other than HIM touches his car unless they are a dealer or ASE mechanic. I'm pretty sure he was implying that he changes his own battery.

And for me the "should" is the key work in your statement above. I know I CAN (not should) and will do it correctly without breaking the panels and clips that have to be removed to get the battery out of this car - yup, it's more than just a bracket and leads. It's not hard, but I choose to not to gamble on should. Plus I personally enjoy working on my cars. Saving money is not the reason I choose to do my own car maintenance.

What we have here is a simple difference of opinions, that's all.

[Ilya]

I know guys who can't change a headlight bulb (on older cars where they are easily accessible). Not everyone is handy around a car...I'm sure the OP can handle it but perhaps his time is more valuable (lets say he's a CEO or something).

[BlackCat81]

Why do you need a delaer or a certified mechnaic to loosen a battery bracket and disconnect the battery leads. This is not rocket science and any 18 year old (even a HS dropout) should be able to do it without damaging your car.

What about pulling half the wiper cowl out or re-learning auto window features? I wouldn't want some random dude fumbling around my car.