I have a few of these Battery Tender Juniors http://amzn.to/28VMCYc and I've used them on my other vehicles no problem.

Here is my question since I'm new to Jags. Can I pop the trunk, hook up the battery tender, and not disconnect the battery from the car? I would very much prefer to keep the battery connected but I don't want to cause any problem.

Thx.

 

I use a Ctek battery tender all the time permanently connected to my battery with no problem at all.

I do not use my car as a daily driver so it can sit for a week without use.

I do not disconnect the battery when using the Ctek.

 

+1 on Ctek. I do the same. No disconnecting the battery...

 

I guess another question would be can I just leave the trunk open to run the wiring out? How do you run the power cord?

 

With Ctek they sell an adaptor that hooks direct to the battery and then you attach the unit to the liner of the trunk and connect the Ctek to that. (No worries about clips falling of the battery posts)

Either way the wire is thin enough I run mine through the trunk with a bit of slack then close the trunk.

You don't want to leave the trunk open. That would defeat the purpose of charging.

 

Is there not a power save relay that shuts off the power to things like the trunk light after a time (as there is on my car)?

 

Here is my CTek hookup, with the trunk slightly ajar. It's been charging for >2 weeks now. Never a problem.

 

I do what you do Wolfy however I actually let my trunk close all the way. The thin wire, red/black does not leave an imprint in the rubber around the boot.

 

+1 on charging with tender connected to still installed battery.
+1 on leaving boot lid slightly ajar as the lights power off automatically after a short period of time.

 

+1 for Ctek.

(Jaguar actually sell Cteks but they're labeled 'JAGUAR' and are twice the price. Ditto RR, and other quality car manufacturers)

 

I already have a Battery Tender Jr so that's what I'm going to use.

 

I too leave my Ctek connected to the car with the battery connected. Just don't forget to unplug it before you pull out of the garage like I just did 30 minutes ago... I had it on top of the toolbox too so it jumped to the ground and made a terrible sound, thought I blew a shock or something and had a mini panic-attack

 

Loop the extension cord over the driver's side mirror so you don't forget.

 

That's a really good idea, but sadly I have to back my car into the garage (Front lip hits concrete step otherwise) so the tender is behind the car a few feet away from the trunk.

 

Just to be sure, there's no harm in charging the battery for days/weeks on end. Correct? I drive the car maybe 1, 2 times a month.

 

As long as we're clear on the difference between a trickle charger and a battery tender.

The tender will have a voltage trigger. When the battery voltage drops below XXX volts, the tender begins charging the battery. When battery voltage reaches XXX volts, the tender will stop charging the battery. Different brands have different voltage triggers for on/off. When using a tender, you can always plug it in.

A trickle charger, though low voltage, never stops sending voltage to the battery. You can, over time build up gasses in an enclosed space such as a trunk. When using a trickle charger, use less often, maybe every other week and set a meant timer to monitor it and disconnect.

Wolfy, your set up is the model for others.

 

I had what was supposed to be a "battery tender" from Harbor freight on my seldom driven 86 DD6 battery and over 8 months or so it ran the battery dry and ruined it. Guess you have to be careful about the claims of these Chinese units.