Hello,
This is probably too late to be of use, but I will always buy the biggest battery that will fit and go for one that has the highest cold start torque value - that is the amount of power it will produce when you turn the key to start it. Out of interest, the last battery I bought for my Bi-Turbo actually came from BMW themselves. It's a monster battery and the price was pretty good!
Hej hej!
Dave.
This is probably too late to be of use, but I will always buy the biggest battery that will fit and go for one that has the highest cold start torque value - that is the amount of power it will produce when you turn the key to start it. Out of interest, the last battery I bought for my Bi-Turbo actually came from BMW themselves. It's a monster battery and the price was pretty good!
Hej hej!
Dave.