+1. I have occasionally left the car sitting for weeks at a time with no need for a tender. The OBD issue created the tender conspiracy theory.

 

I have had a Battery Tender on my F type for 3 years with no issues. There are instructions on where/how to connect it someplace on the Forum. I have had a Battery Tender Jr on my MGB for decades - every spring, I let the fuel pump pressurize the system, pull the choke and it starts like it was already warmed up. Has paid for itself many times in avoiding new batteries.

 

I have the pig tails on both our cars.

 

I use a CTEK 4.3 charger on my 2011 XK. It is connected directly to the positive and negative terminals of the battery and I have had no problems. In view of the fact that the battery has a BMS attached to its negative terminal, shouldn’t I attach the negative lead of my CTEK wiring harness to a chassis ground instead?

Would I be at risk of damaging any electronics in my car if I do so?

This video seems to explain the charging process clearly. I just want to make sure I'm not going to damage any electronics.

https://fordauthority.com/2022/11/fo...by-technician/

 

Jaguar's instructions for connecting such a charger says to connect to a ground point rather than the battery terminal, so I assume they have a good reason.

 

Thank you for that information.

I will change my connection to a ground point.