Changing battery
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Joined: Aug 2023
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From: Austin, Tx
Changing battery
Ive done some research and cant find a definite answer so looking for that here.
Do I need to have a 120 to 12v converter connected to the obd port on my 991.2 to prevent loss of settings, etc. while changing out the main battery?
Do I need to have a 120 to 12v converter connected to the obd port on my 991.2 to prevent loss of settings, etc. while changing out the main battery?
Last edited by Kilo Papa; Oct 12, 2023 at 10:17 PM.
Racer
Joined: Jun 2021
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From: New Orleans, LA
I changed my battery with no loss of settings. I did it quickly. If you're going to another heavy AGM battery have an assistant because of the weight of the battery. A long piece of wood through the battery straps allows you and your assistant to stand at each side of the car to lift it out and replace it quickly.
There's a simple device you can purchase at an auto parts store, one end plugs into your cigarette lighter socket and the other end has plugs for a 9V battery. Maintains a 9V charge to the car when the battery is out. A further safeguard for keeping your settings. If you can afford the cost of a lithium battery you can lose 40lbs. from the weight of your car. That is what I did.
There's a simple device you can purchase at an auto parts store, one end plugs into your cigarette lighter socket and the other end has plugs for a 9V battery. Maintains a 9V charge to the car when the battery is out. A further safeguard for keeping your settings. If you can afford the cost of a lithium battery you can lose 40lbs. from the weight of your car. That is what I did.
Last edited by straka; Oct 12, 2023 at 11:03 PM.
Racer
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From: WI
Theres some controversy with powering your car without a battery in it.
Theory being the battery acts as a filter smoothing out any voltage fluctuations. Without that protection you risk smoking some sensitive electronics.
Theory being the battery acts as a filter smoothing out any voltage fluctuations. Without that protection you risk smoking some sensitive electronics.
Racer
Joined: Jun 2021
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From: New Orleans, LA
I've had an Antigravity brand battery for a year. No need to change settings. There is charging protection built into the battery. Lots on rennlist about their batteries. Their website is very informative.
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I swapped out to a new AGM battery (there are three sizes for our cars, I got the largest because that's what was locally available and other factors were more important to me than weight). I did not have power connected during the swap and had zero issues. I also programmed the car for the new battery, something I'm still not sure is really necessary (see the many threads about this).
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From: Austin, Tx
I swapped out to a new AGM battery (there are three sizes for our cars, I got the largest because that's what was locally available and other factors were more important to me than weight). I did not have power connected during the swap and had zero issues. I also programmed the car for the new battery, something I'm still not sure is really necessary (see the many threads about this).
Seems most say no need to run aux power while changing the battery. I was planning to simply plug the ctek into the 12v power outlet until I read abt the possibility of frying some component by providing direct power without the battery to modulate it. While I need to think about that notion a bit more, Ill probably swap it out without any aux power like I have done many times on other cars.
For those of you that did a direct swap for another AGM, which is what I plan to do, 2 quick questions: (and I AM aware of the discussion here about whether entering the new battery info into the pcm is nescessary)
1- did you enter the new battery info into the system (even though you hafta lie to it re SN, model etc., if you buy non Ppart)
2 Did you swap for a similar size battery or a smaller agm version with similar power specs?
Thanks for the input.
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From: Canada & the Alps
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From: Canada & the Alps
Racer
Joined: Jun 2021
Posts: 345
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From: New Orleans, LA
All I know is the cigarette lighter switches OFF after 6 minutes. Will that still work with that device connected? I have that device as well but I have never used it. My damn factory installed batteries last the life of my car.
But $1200 vs maybe $250 or less for an AGM. If weight is that important, fill your boots, but it won't last any longer than an acid battery.
But $1200 vs maybe $250 or less for an AGM. If weight is that important, fill your boots, but it won't last any longer than an acid battery.
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From: Austin, Tx
My current AGM is at 5yrs and showing no sign of weakness but Id like to swap it now and get that box checked off.
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From: Canada & the Alps
I'm not worried about weight and don't want to further upset an already tail heavy bias.