About to change battery for first time

[Nytimes770]

I bought an agm battery from Walmart mart and plan to change the battery today.

What are the steps I need to follow after changing the battery? The manual says something about applying the parking brake and putting in park or neutral, and eventually driving for 10 miles.

I also read in forums about flashing the high beam and tapping on the brake x number of times.

Are both sets of instructions necessary?

 

[Dice Roll]

I let mi e sit for 24 hours, way longer than the manual states is necessary to reset the bms. No dice. Only after the Hokey Pokey dokey dance of flashing lights etc did it reset. Be sure you see the battery icon flash. Instructions are widespread. I don’t recall the exact combination.

That resulted in the auto stop working again. It was locked in the “vehicle charging” loop so I knew it wasn’t registering the new battery. If you let it go, it will hurt your new battery as it starts a process called shedding.

 

[99WhiteC5Coupe]

I bought an agm battery from Walmart mart and plan to change the battery today.

What are the steps I need to follow after changing the battery? The manual says something about applying the parking brake and putting in park or neutral, and eventually driving for 10 miles.

I also read in forums about flashing the high beam and tapping on the brake x number of times.

Are both sets of instructions necessary?

I would follow the instructions in the vehicle owner’s manual.

 

[Danm355]

You can also use a battery memory saver which maintains power to the system when you unhook the battery.

 

[Fizzy]

You can also use a battery memory saver which maintains power to the system when you unhook the battery.

I used my Noco battery charger/maintainer in 12v supply mode connected to both terminals to keep the memory saved whilst the battery was disconnected. Just don't do anything silly like trying to lock/unlock the car. You want the absolute minimum draw for the 30 seconds it takes to switch out the batteries.

Then once the battery is replaced, follow the BMS reset procedure. I don't buy the story about the "sit for 8 / 12 / 24 hours", and even so, why wait when you can just spend 11 seconds doing the reset procedure.

 

[East-TN]

I bought an agm battery from Walmart mart and plan to change the battery today.

What are the steps I need to follow after changing the battery? The manual says something about applying the parking brake and putting in park or neutral, and eventually driving for 10 miles.

I also read in forums about flashing the high beam and tapping on the brake x number of times.

Are both sets of instructions necessary?

Use the BMS reset procedure and you will be fine. I just changed the battery in my 2019 using the BMS reset with no problems.

 

[Danm355]

I used my Noco battery charger/maintainer in 12v supply mode connected to both terminals to keep the memory saved whilst the battery was disconnected. Just don't do anything silly like trying to lock/unlock the car. You want the absolute minimum draw for the 30 seconds it takes to switch out the batteries.

Then once the battery is replaced, follow the BMS reset procedure. I don't buy the story about the "sit for 8 / 12 / 24 hours", and even so, why wait when you can just spend 11 seconds doing the reset procedure.

Correct me if I'm wrong but I thought I read somewhere that if you maintain the power to the system when changing the battery you won't need to do the BMS reset. Does anyone know this for certain.

 

[Dice Roll]

You need to reset it so it will charge the battery correctly. It can hurt the battery through a process called shedding if the computer doesn’t know it’s a new one.

 

[Fizzy]

Correct me if I'm wrong but I thought I read somewhere that if you maintain the power to the system when changing the battery you won't need to do the BMS reset. Does anyone know this for certain.

The BMS tracks all kinds of parameters and behaviours for your old battery. How quickly it charges. How rapidly it discharges. How much charge it will hold. Using all this, it determines a battery management strategy to extend the life of for your battery, which changes and evolves over time as the battery gets older and weaker.

The reset tells the BMS there's a new battery, and it should forget all the charge/depletion/capacity parameters it was tracking for the old aged battery under its care, and to start fresh.

At least, that's my understanding of what's happening. And again, for the 11 seconds it takes to do the reset procedure, why wouldn't you do it?