12 Volt Auxiliary Battery East Penn Deka AUX18L

[spartacus68]

So couple questions, what's the 40AH version for, and if you fitted would it last any longer, or do these batteries simply fail with age regardless of AH rating.

The 40 AH battery is a larger size, and requires modification of the battery tray and a different windshield washer bottle installed to make room for the bigger battery. It was used as stop-gap alternative replacement to get a car back on the road during a shortage of the 20 AH battery. Longevity would be the same.

Interesting - thank you. I'm not contemplating adjusting the battery tray or washer-bottle, the 20Ah will do!

[jadnashuanh]

Do you happen to know what software version made this change? And how to check which software version you have in your car?

No, I read it somewhere on the forum. You can probably get an answer from the Genius line or from your service manager. Someone may remember, and post it (again).

[alohart]

It used to be, if you wanted to trickle charge the battery, you had to pull the HV disconnect first. Supposedly, that changes, depending on what system software is in your vehicle. Because the vehicle disconnects the 12vdc sockets in the vehicle, you can't use them to maintain the battery...you have to go to the battery terminals themselves unless you wire in a path specifically for that that might be more accessible.

Do you happen to know what software version made this change? And how to check which software version you have in your car?

According to BMW's TIS:

"If the integration level in the vehicle is up to and including 14-03-504, then the high-voltage system must be deactivated.
If the integration level in the vehicle is 14-03-505 or more recent, then it is not necessary to deactivate the high-voltage system."

This is the system software released in March, 2014, so very few i3's ever ran this version and fewer yet still do.

Even though our 2014 BEV was delivered with July, 2014, system software that has been updated to later versions several times, I still disconnect the high-voltage disconnect prior to disconnecting or charging our 12 V battery. It's easy to do and isolates the high-voltage system from the 12 V system, so I do it to be extra cautious with expensive components.

The Integration level is the value of the <i-step> tag in the driver profile backup. Just open this backup in a text editor to find the integration level.

[Fisher99]

Thanks Art. Good info.