New member. Have continuing problem with 06 XLR battery drain since new, Have gone thru 4 batteries (#5 this week). That is the usual dealer fix. Obviously continuing drain when car shut down. Dealer says normal but car does not sit for extended periods. Appears to me to be a transient in the system but does not appear when dealer tests. Anyone else with similar probs??

New member. Have continuing problem with 06 XLR battery drain since new, Have gone thru 4 batteries (#5 this week). That is the usual dealer fix. Obviously continuing drain when car shut down. Dealer says normal but car does not sit for extended periods. Appears to me to be a transient in the system but does not appear when dealer tests. Anyone else with similar probs??

Mine gets driven alot but if the weather is bad it has sat for 2 weeks before and never a hint of a low battery.

There are a number of different ways to isolate a constant draw. I don't know your abilities or access to test equipment (like a multi-meter) so I'll toss the easiest method(s) I know into the Realm of Uncertainty:

Unless you posess a photographic memory, you need to keep detailed notes when you do any of this:

With a multi-meter, measure the voltage across the battery every 6 hours for a day and-a-half to determine the amount of drop. Let's say you see 14.3 vdc the first day (a good nominal charge) and 12 volts 18 hours later. That would be a 16mV drop every hour which is your baseline. Remove ten fuses to start and measure the battery voltage every 6 hours. If you still get another 1 volt drop after 6 hours time, re-install the fuses, charge the battery up to 14.3 and pull another set of fuses, repeating this process until the voltage doesn't drop anymore. When you get to that group, insert one fuse at a time, wait, take a measurement until you get a voltage drop, and you'll at least know what circuit to start troubleshooting.

If you know how to measure current, it's faster to put the multi-meter in the main circuit and measure the current draw while systematically removing and replacing fuses until it changes appreciably. Under normal conditions, there will always be a current draw due to some circuits that are continuously monitored, but if your car is pulling a pretty heavy load, you'll usually recognize a big change when you see it. Pulling certain relays will cut all power, so you really need to have a firm understandng of the functions of the components you're working with.

If you have a shop manual, plenty of beer in the fridge and understand the circuit diagrams, you can have a fun weekend project on your hands. --Otherwise, you're pretty much dependent on the dealership's tech. The Tech 2 scan tool they use can detect shorts that can cause your symptoms. I would assume they ran a complete XLR diagnostic when you took it in, but . . .

Also, ensure your software has been updated to the lastest revision as there was a circuit (RCDLR) causing parasitic drain that had it's firmware changed to effect a fix.

I know this is pretty generic troubleshooting guidance, but without being there and poking around myself, I'm totally reliant on the sympyoms you describe. If you come back with more info, maybe I can offer better advice.

Hope this helps a little,

CC :cheers