Memory saver for battery swapping

[sarujo]

Re all,

Factory battery is getting tired and it's time to replace. Anyone use one of those "memory savers" that plug into a live cigarette power port or ODBC port and use a 9V battery or other 12V power source? I want to retain computer settings to avoid re-learn issues and potential t-body/MAF sensor re-clean. I don't care about the radio settings.

Any particular models that worked for you - would love to hear about.

Thanks!

[dentinger]

I want to retain computer settings to avoid re-learn issues and potential t-body/MAF sensor re-clean.

um, what?

[sarujo]

um, what?

Umm..when you disconnect the battery the PCM loses settings and engine must re-learn idle etc after battery is re-connected. If your throttle body is too dirty you may be forced to re-clean so it can re-learn properly before idle etc is restored. I want to avoid this potential hassle and retain computer settings while changing the battery.

[SonicBoy]

I have both a 9V one (http://www.amazon.ca/gp/product/B00DVHL184?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00) and one that plugs into your ODBC port (http://www.amazon.ca/gp/product/B002J8LMZS?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00)and into one of those portable power units via a Cigarette lighter.

I have not used them yes so cannot provide any real feedback.

Picked them up on Amazon.ca

[dentinger]

I have changed hundreds of batteries in my life, and I've never had to relearn anything. Don't know where you're getting this information from but you'll be fine.

[SonicBoy]

With clean air, it now tests the car's computer for any codes. These devices can be used to minimize the re-learn process that happens when you disconnect.

For some cars, it can take days for the relearn to happen and reset the codes for clean air test to be performed.

[sarujo]

I have changed hundreds of batteries in my life, and I've never had to relearn anything. Don't know where you're getting this information from but you'll be fine.

With over 6000 posts here I am surprised you are not that intimate with the MZR motor.

I cannot speak for the new Skyactiv power plants, but the MZR is quite unique and sensitive when the computer has been cleared (ie when a battery is disconnected or changed) and must re-learn. It typically involves extensive idling and/or re-cleaning of the tbody and MAF sensor followed by a reset.

This thread is about what memory saver devices people have used successfully. Let's keep this on track...

[sarujo]

I have both a 9V one (http://www.amazon.ca/gp/product/B00DVHL184?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00) and one that plugs into your ODBC port (http://www.amazon.ca/gp/product/B002J8LMZS?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00)and into one of those portable power units via a Cigarette lighter.

I have not used them yes so cannot provide any real feedback.

Picked them up on Amazon.ca

Which ODB one do you have?

[Flagrum_3]

With over 6000 posts here I am surprised you are not that intimate with the MZR motor.

I cannot speak for the new Skyactiv power plants, but the MZR is quite unique and sensitive when the computer has been cleared (ie when a battery is disconnected or changed) and must re-learn. It typically involves extensive idling and/or re-cleaning of the tbody and MAF sensor followed by a reset.

This thread is about what memory saver devices people have used successfully. Let's keep this on track...

I respect that you're worried, but seriously I don't think you'll have an issue. Once you've replaced the battery just take the car for a nice long drive, maybe an hour or so and drive as you normally do. Take it for a nice jaunt on the highway and get the rpms up there also.. It should relearn everything fine and I don't think the TB will be an issue whatsoever. When I replaced my oem battery not long ago, I hadn't had the battery disconnected for quite a while and had never cleaned my throttle body either, and I had no issues whatsoever.


_3

[SonicBoy]

Provided links to both items in my post: one that plugs into your ODBC port (http://www.amazon.ca/gp/product/B002J8LMZS?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00) <== clicky




Which ODB one do you have?

[rajin929]

i used one of those portable power booster packs and connected to the terminals before disconnecting the battery to swap it out.
i lost the radio security code on my accord and didn't want to disconnect the battery completely

i've heard of people using the 9V battery, but never tried it myself

found this online...


https://www.youtube.com/watch?v=9HREVVZAqNI

[SonicBoy]

You cannot simply hook up a 9V battery to your existing battery. You must have a diode in the mix.

[Cab0oze]

I'm almost positive that you have to have your battery disconnected for quite a long time to lose your ECU maps. It's not something that happens as soon as the battery disconnects. A simple battery swap (battery disconnected for a few minutes) will only clear your radio presets.

Back a few years ago on my old 2004 mazda3 I was trying to force it to relearn, and I had to leave the battery unplugged for like an hour or so to get it to work.

[FD22]

ryan2.3 sounds about right huh lol


OP, as others have mentioned, its not a necessity to do. If however you're doing it out of personal preference, then that's totally fine.

I don't have suggestions on where to find what you're looking for, but just wanted to chime in here in case you thought you "had" to do this. My TB was cleaned only about 1.5-2 years ago, and I've never cleaned my MAF. I had my battery disconnected for about an hour or so when replacing my alternator a few weeks ago, and didn't do anything special to the car after starting back up. Simply let it re-learn itself. Took about a day or two to get back to smooth sailing. It was idling extremely rough at first, and even in first gear it felt very sloppy. Higher gears/speed weren't too noticeable of a change. It may have taken my car longer to re-learn due to my tune though, but it was definitely quite a rough idle for the first few hours after.

[ryan2.3]

haha forgot to ask you if that cleared up eventually.. glad it did

Regarding memory saver, just hook up a trickle charger to the battery leads so you have no power loss while you swap out the battery?

[r4BBiT]

Umm..when you disconnect the battery the PCM loses settings and engine must re-learn idle etc after battery is re-connected. If your throttle body is too dirty you may be forced to re-clean so it can re-learn properly before idle etc is restored. I want to avoid this potential hassle and retain computer settings while changing the battery.

FYI. The only thing that the car needs to re-learn is the fuel trims (Short Term Fuel Trim and Long Term Fuel Trim). There is absolutely no learning involved with Throttle Body, MAF, or idle.

Throttle Body has a simple 2D translation map where one value converts into another (e.g. 10% is 7.5% in ECU's eyes). The same story goes for MAF; i.e. certain volts translate to some g/s of air. The idle is "hard-coded" with certain value based on the Engine Coolant Temp (and maybe atmospheric pressure; I don't remember of top of my head).

Just so you know you car is constantly changing STFT and LTFT so you are really overthinking this thing.

[SonicBoy]

Had a chance to use my memory saver yesterday while replacing the battery in our 5. Plugged the cable into the OBD2 port then into my CdnTire battery pack 12V outlet.

This is the best method as the ones that plug directly into the cigarette lighter may be switched which mean you turn the key to Acc and other items are on in the car drawing electricity. The other ones pictured above that connect via clips to the battery cable are prone to fall off while wrestling with the heavy battery removing and installing.

Disconnected the connections from the battery wrapping them in cloths to insulate and prevent them from touching each other or body parts. Swapped out the battery and reconnected everything. Unplugged the Memory saver and fired up the car.

Clock was right and all memory presets still there. Car idled just the same as when I parked it before the swap. No rough idle or any notice driving afterwards.




Provided links to both items in my post: one that plugs into your ODBC port (http://www.amazon.ca/gp/product/B002J8LMZS?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s00) <== clicky


Wow! the price has really gone up. I paid only $19 for this last year.