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Hi everyone,

I am seeing some conflicting information online and while searching the forums. I need a new battery in my 2015 L405, is there anything special that needs to be done when changing the battery? I've seen some talk saying that the battery monitor module needs to be reset after being changed, and that all memory may be lost. Do I need to take it to the dealership? I can't find much beyond that online for L405 battery replacements.

Thank you

 

[BLUESURF]

Get one of these and you should be set.
https://www.amazon.com/Powerbuilt-648539-Computer-Memory-Keeper/dp/B004BW9J1Y

 

[ASGIBM]

I don't think there is any socket that is "on" when the "key" is not in ACC position...so I am not sure it will back flow the 9V into the vehicle...Did you check the owners manual to see what it said about the battery?

 

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I don't think there is any socket that is "on" when the "key" is not in ACC position...so I am not sure it will back flow the 9V into the vehicle...Did you check the owners manual to see what it said about the battery?

Yes I checked it, there was nothing in the replacing the battery section beyond a notice

Does anyone know if the battery monitor module actually needs to be reset when battery is replaced?

 

[bWiLKINS]

I have replaced mine twice myself with no issues in my 2014. Disconnect the old one, remove, put the new one in and reconnect. You will need to cycle all 4 windows fully up/down is about the only thing I noticed needs to be done after you reconnect the new unit. I did not do this the first time and the rears refused to go down, had to disconnect/reconnect and cycle them to get them working correctly again.

 

[OldScoolFool]

I have replaced mine twice myself with no issues in my 2014. Disconnect the old one, remove, put the new one in and reconnect. You will need to cycle all 4 windows fully up/down is about the only thing I noticed needs to be done after you reconnect the new unit. I did not do this the first time and the rears refused to go down, had to disconnect/reconnect and cycle them to get them working correctly again.

Well first thing I have to say is that an AGM battery is good, if properly cared for, for 6 years plus, to have replaced 2 in 4 years (2014 model and a 2018 post) suggests an issue beyond a battery. Not too mention that would have been covered under warranty so why would you change it yourself?
Secondly, the battery module should be reset at every battery change otherwise the alternator and battery module will destroy a new battery because if the system is unaware it is a new battery, it will continue to treat the replacement battery the same way it was last treating the replaced battery. So if the battery was low and the system is telling the alternator to pump amps in, then that new battery will be overcharged and its life expectancy dramatically shortened.
It's more than just keeping memories alive when changing, it's just like your oil service indicator it has to be reset to work.