[sismy]

I'd like to thank all the previous posts from E90Post members regarding to DIY battery change.

I just got my battery replaced and the result is, in one word, fantastic! Everything on the car is just much smoother than before! And the revving is significantly quicker and smoother and make the gear change much connected! Originally I had to touch/tap the throttle a little bit when shift up because the rpm used to drop quicker than a normal gear shifting once I release the throttle. I'd like to list some pieces of information as follows for people who may need a battery replacement in the future.

Car: E92 2008 335xi 6mt
Originally battery: lead acid 90ah 720cca (it's been lasting 8 years, 4307!)
Replaced battery: lead acid AAP Autocraft gold 49h8 900cca
Backup power during change: No
Registration: Carly with iPhone

Note: I'm not an expert and I don't have a clear evidence about the benefit of battery registration. But I seemed observe the different charging pattern after battery replacement and registration.
I got an aftermarket HUD that shows several information including voltage.
Before the replacement, when I was driving the car, it was usually somewhere around 14.6; and 14.8-14.9 if the weather is very cold. Also the voltage will keep dropping (12.8, 12.7, 12.6, ...) after I shutdown the engine.
After the replacement, during the test drive today, it's around 14.1. After I shutdown the engine, the voltage was holding on 12.7-12.8.

I got the feeling that the alternator is using less power to charge the battery now and the battery holds the power very well.

Overall, I'm very happy with the DIY replacement. Thank you all people on E90post who shared so much information.