Replacing battery in 2014 / 2015 Mazda3s

[blondee_yvr]

I have watched a few youtube videos and it appears some have struggled to remove the housing bracket for the battery.


Nothing much was mentioned on using a battery tender or something like an AC battery charger or how to use to preserve your infotainment settings and preventing your ECU, PCM from "re-learning". For this reason, I take whatever I see on youtube with a grain of salt as it's always incomplete.

From previous experience on older Mazdas and other vehicles, a battery tender is needed, not so much to preserve the radio settings, but to prevent the ECU from re-learning.

Any tips?

[concept]

When I had my 2001 Corvette, I could plug a 9-volt battery adapter cable into the cigarette lighter receptacle before disconnecting the old battery. This would preserve the radio and other settings. However, it may not work in other vehicles. I would not connect a battery tender to the battery cables and then disconnect them from the old battery unless this was shown in the BT manual as acceptable.
But really, how often do you change your battery? Is it really a major pain to reset some things? 10 minutes every 5 years is nothing, at least in my book.

[blondee_yvr]

But really, how often do you change your battery? Is it really a major pain to reset some things? 10 minutes every 5 years is nothing, at least in my book.

I guess you missed the part where I mentioned the issue was not preserving the battery, but the engine (ECU) needing to re-learn how when to shift. Had you experienced this, you would know how much of a nightmare this is and the premature wear on the components. Dealers do use a battery tender or a battery backup when they change the batteries, for this very reason.

[concept]

So you're saying that the relearning process creates premature wear? Where did you read that? I have replaced dozens of batteries in ECU-equipped vehicles and never had a wear issue that caused problems. You may be overthinking this.

[negusm]

They use a battery tender to not lose those settings but it's not going to cause undue wear. They should just stop building new cars if they are so fragile.

[blondee_yvr]

So you're saying that the relearning process creates premature wear? Where did you read that? I have replaced dozens of batteries in ECU-equipped vehicles and never had a wear issue that caused problems. You may be overthinking this.

I wish I was. From experience when a battery tender or OBDII memory/ECU setting saver were not used, the car had to re-learn the IDLE. In some cases, and it's not consistent, the power window and sunroof controls needed to be re-learned too. The latter are described in Mazda's tech manual, but not the idle re-learn procedure.

[negusm]

I wish I was. From experience when a battery tender or OBDII memory/ECU setting saver were not used, the car had to re-learn the IDLE. In some cases, and it's not consistent, the power window and sunroof controls needed to be re-learned too. The latter are described in Mazda's tech manual, but not the idle re-learn procedure.

But none of that produces undue wear.

[blondee_yvr]

But none of that produces undue wear.

I don't know. At the very least, the drive would be terribly uncomfortable especially from people not used such rough idling.

[concept]

Simply driving your car a minimum number of miles allows the ECO to relearn. Every time I replace the 12V battery in our Lexus RX400h, I have to relearn the windows and moon roof. It takes me 3 minutes and there is no rough idle.