The battery goes dead in my 2006 cady xlr after not driving it for 2 to 3 weeks, is this normal?

anon
steps
1: remove battery neg lug now or blow to H3LL the ALT 100 amp huge fuse, making ALT OFF LINE, , never skip step one,.
2 remove alt ,unplugged and new put back all wires, and big one
3: put back battery NEg lug. on my car honks fast, normal. bcm act on mine.
if you drive with ALT off line (dead) the battery drains out fast
even 1/2 hour and now battery voltage goes way too low
and which computer fails first nobody knows, (chaos)
just like TV clicker goes nuts battery weak, same goes here.

but if BCM fails at 10vdc , what fails are BCM devices.
any lamps or even hazards. dead or stuck on.
normal; voltage driving or idling is 13v to 15vdc, never lower
your module is called FLSH , and can be reset pulling 2 fuses
fuse GAGE and HAz both are 10amps
HAZ fuse is most important to pull key off.

anti theft? bad starter?

Someone will need to check the electrical system on the car for a drain such as a small light or other electrical component.

duplicate question

probably your battery cant conform minimum requirements of digital circuits used to drive starter motor in high tech cars. that is why it works only with external charger. measure your abttery. it should be showing at least 12.4 volts. normally battery should show 12.5. to 12.65 volts. probably your battery has sulfation. end of its life.

alternator diodes is most common cause

Sounds like the battery is a drain on it, check with an ammeter on the red or black wire to see how much. Shouldn't be over .2 A normally.

Also can try changing batteries, as when some batteries get old they do not hold a charge.

If you have the original battery, it's 5 years old.

Typically, batteries last 3 years on average.

matches

In that case, whenever u take it for a ride and return to your nest, lift the hood and disconnect the battery terminal which I would recommend having a clip(spring loaded clamps with metal jaws) removed from the battery. Next time you use it, first reattach the clamps to the batter, and start normally.......sodeep

it is possible with clocks and such to drain the battery after 2 weeks. if you can't let it run for a while during that time, just unhook negitive battery cable untill ready to use.