I've noticed lately on my '03 X5(newer version) that my engine seems to be turning over a bit slower. The truck has 82K and though I did not look, I would guess the battery is OEM factory. I'm not getting any faults or codes etc. Everything is working fine otherwise.

But now and then, when I turn the key, it just seems to turn over slower than it did before. Weather is just a bit cooler at 60 degrees F.

If I have to change out the battery, when I do the swap, what will happen? Will I lose any functions such as radio lock out b/c I don't have the radio code(I bought my X5 used) or other "memory" features? Could I use jumper cables up front to keep the power going while I change out the battery--being careful not to touch the cable ends to anything of course.

Ideas? Thoughts?