I remember seeing older cars and trucks with a copper strap that always trailed on the ground
attached to various parts of the car. My father informed me that it was a ground strap that
prevented or possibly reduced rust and helped prevent corrosion in various electrical components.
It was also installed by some to prevent static electricity from building up on the chassis. I always
thought there had to be a better way. The best idea I could fabricate was sacrificial anode, although
the complex electrical routing on our Ladies makes such an endeavor challenging. This approach,
however, has a long standing reputation for not being terribly effective.

 

I ran a few tests today as a check on the battery health (Battery health, cranking test, and charging test). Screenshots of the tests are below.

 

Battery health of 80% and state of charge of 57% will hopefully improve when the battery is fully charged, but are currently no good for a Jaguar.

The 10.98 volts while cranking is borderline for a Jaguar. If the voltage sags to about 10.5 volts while cranking, the ECM will not trigger the ignition to fire.

Cheers,

Don

 

"Battery health of 80% and state of charge of 57% will hopefully improve when the battery is fully charged, but are currently no good for a Jaguar. The 10.98 volts while cranking is borderline for a Jaguar. If the voltage sags to about 10.5 volts while cranking, the ECM will not trigger the ignition to fire."

I'll charge the battery to "Full" today and retest. It's 3+ yrs old now with little use, so it might be on the way out. If it's still borderline, I might replace it with the Diehard AGM battery (https://shop.advanceautoparts.com/p/...rchTerm=ulbatt) as they have come down in price to just a few dollars more than flooded batteries, and are a better fit for this car the way I'll be using it (intermittently, and never in winter).

Anyone here have firsthand experience with the AGM technology in this car?

 

I use AGMs in my X308 and X100 with not problems, but I also keep battery tenders on both cars when I'm not driving them.

BTW, there are only three battery manufacturers left in the U.S., Johnson Controls (may be going by a different name now), Exide, and East Penn/Deka. Those three companies make virtually all the brands available here, Advance (formerly Sears) DieHard, GM ACDelco, Ford Motorcraft, Walmart Everstart, NAPA Legend, AutoZone Duralast, O'Reilly Super Start, Optima, etc. I look for the highest CCA and Ah ratings I can find. AGM batteries usually have slightly lower CCA ratings, but better tolerance of being deeply discharged.

Cheers,

Don

 

I use the AGM style in the Duchess with no significant difference from
the regular batteries. The one difference that may be merely perception
is that it seems to charge faster. The other thing I noticed is that it cost
more.

 

Test results improved when the battery was fully charged. I'll be traveling next week for 8 days, so we'll see where it sits when I return.

 

With the battery Cold Cranking Amps capacity at 84% after being charged, it's tired. Probably time to replace it.

 

New Diehard 900 CCA AGM battery is now installed. We'll see how this holds up over a week of my absence without a trickle charger.

 

Sometimes, a new battery can really make a difference in the way
we perceive the operation of these fine ladies.

 

Today the car is in the shop having the transmission fluid and filter changed, and the main pressure relief piston upgraded and replaced. Then, it's back to my garage for more primping until the snow melts and the snow goes away.

 

Back home now, and the old droopy headliner is gone, and a new one is installed. Also, replaced the front swaybar bushings to vanquish a clunk in the font end. Easiest and cheapest suspension work ever! Lastly, replaced the front engine protection pan, as the passenger side was missing.

 

Dang. The car is stuck in park. The "P" is illuminated. Pumping the brake has no effect. Car starts and runs normally, no codes. Nothing appears amiss with linkage underneath. But, that shifter won't budge. So, popped out the little star-drive screw in the face-plate, inserted a small screwdriver, and tripped the latch holding the shift lever in place. It's off to the local mechanic to diagnose. Hopefully, no big deal.

 

Bet that's the brake light switch failed. You've probably got no brake lights either as the ECUs use that signal to know the brake pedal has been depressed to allow you to select any gear positions.

 

Gentlemen... place your bets.