I am about to put my new, to me in May of 2020, , 2002 XK8. I have bought a battery maintainer but question the best way to hook it up. In looking at the owners manual, it seems that they recommend attaching the red "+" to the positive post on the battery, and the black "-" cable to the tie down bolt for the spare tire. On my other cars I attach the red to the positive post and the black to either the negative post or to the frame of the car. Also I have always heard that you should attach the negative cable first and the positive cable last, and when disconnecting, remove the positive cable first. Have I been doing it wrong?

 

I think you're overthinking this. Follow the instructions that come with the charger.
I typically charge a battery on the work bench with the charger clamps on the battery posts.
I just installed an electrical panel in the trunk of my car that incorporates a 12 volt socket. I discovered it on this forum.
I found a convenient hot battery positive stud at the fuse box just behind the battery so I connected to that.
There is a ground stud right next to the battery and I used that.
I put a matching plug on a trickle charger and it works great. All I have to do is open the trunk and plug it in.

 

There is no need to connect to the battery. Use the fuse box on the left side of the engine compartment like I do for my CTEK maintainer in the attached pic.

 

Yes, you’ve been doing it backwards.

the reason you remove the negative cable first is that is doesn’t matter if in doing so, you brush it against the frame.. likewise, with the negative disconnected first and out of the way. The positive will not cause a short if it subsequently touches the frame

however, if the negative is connected to the battery and you remove the the positive first and it touches the frame, then you have short circuit.

Z


PS. i would like to know the credentials of the people telling you the back-assward way of handling automotive electrics.

PPS. I have my batter tender pigtail wiring connected directly to the battery and cooled up to the trunk. Whenever the car will not be driven overnight or longer I just open the trunk and connect the pigtail to the garaged tender connection.

The good people of this forum assured me that I can close the trunk on this exiting charger wire without causing any damage to the wire or to the trunk weatherstripping. And they are correct.

 

Perhaps old skool and used to positive ground electrics? When I was a lad...

Another good reason for removing the ground (-ve) connection first is that it doesn't matter if your wrench hits the bodywork. If it does so while removing the positive first then you may end up with an unintentional spot weld or two

 

my first real mechanic job was at the Triumph Motorcycle Dealership in Oklahoma City. At that time
(1969-‘70) ALL of the British motorcycleswere positive earth, not to mention the use WhitWorth and British Standard sized wrenches.


spot welds ? I have to LOL. Sparks a plenty !!

There’s many a 10mm wrench with a tell-tale dark spot on the end where it hit the frame while loosening the positive terminal in the wrong order.

Z

 

My trickle charger instructions say to connect it to the battery before plugging it in so it doesn't matter which order I connect or disconnect because it's not putting out anything when I'm connecting/disconnecting it. But now with the electrical panel in the trunk, I plug the charger into the panel, then plug it into the 115 volt outlet.

 

it would only matter if you brush the frame with a positive connection (Clamp) to the battery terminal at the same time, and the battery’s neg cable is in place.

A old power company lineman once told me to “always make your last connection be the one to the power source, (115-120v in our example) and you'll live a lot longer ...”

although I’ve never smelled any gasoline fumes in the trunk area, I still prefer to avoid the possibility of making a spark inside the trunk when connecting my battery tender by leaving the plug in to 120v power for last just like you do

 

I see what you're saying but I always removed the battery from the car for charging so it's on the workbench.
If you charge the battery in the car, yeah, connect positive last.
Now I just plug the trickle charger into the socket in the trunk panel so no worries.

 

+1 !

Removing the battery for charging is hands down the safest charging scenario, and not bad exercise either. I’m only lacking the willpower to go that route.

 

I'm getting to the point that I can do without the exercise. LOL
Anyway, my trickle charger puts out 13 volts, which is less than the voltage from the alternator so I see no safety issue there.
I wouldn't put the regular 6 amp charger on the battery unless it was out of the car. The trickle charger's job is to make that unnecessary.

 

Have a look at this thread for some photos of how I used the cable that came with the Battery Tender.
https://www.jaguarforums.com/forum/x...estion-203716/

 

Not meaning to hijack the thread,but,,,,, Had to chuckle at your comment. My 59 Austin Healey Sprite was a positive ground, The learning curve was quite spark intensive....