I'm wanting to attach my CTEK battery tender to my XKR battery, and noticed there is an extra set of threaded posts attached to the battery terminals without a nut on them. I really want to attach me CTEK to those but don't know what size nut will fit. Does anyone else know what size they are?

 

I know this is an old post but for anyone that's interested the answer is an M6 hex nut.

 

I use the alligator clips - easy on/off, and no problems.

 

There is always a chance that the alligator clips can come loose and get dislodged in the boot. Connecting the rings to the screw down posts is more secure and worry free in IMHO.

 

If I'm not mistaken there is an easier way to do this than exposing the batt. I think there is an access panel on the left side of the boot . I saw an 07 XK with a dead battery started from this panel at a dealership last week.

 

Yup but the problem with that approach is you still need to access the negative which is located in the spare tire well. Once the remote extension leads are connected to the terminal posts you don't need to remove the battery compartment cover again excpet of course to service the battery if necessary.