Typical discharge rate for a stored battery

[CBL302@xxxx]

The Golden rule to remember about automotive batteries(lead acid 
batteries)is that they discharge at the rate of 1%(one percent)(for a 
good,fully charged battery)a day,that means that if you let your car 
sit for a typical month(31 days)your battery is 31%(thirty one 
percent) discharged,after 100 days of sitting unstarted your battery 
is 100 percent discharged.It also depends on your climate,the colder 
the climate(the lower the temperature) the more CCA's(Cold Cranking 
Amps) you will need to crank over your engine,(meaning that a battery 
in a cold climate fifty percent discharged may not be capable of 
starting up a car) vs someone in a hot climate,their car would most 
likely crank over and start even if their battery had been sitting 
unstarted (discharged)for 90 days (ninety percent discharged).
Hope this helps,when you go trying to take your Deloreans out of 
Hibernation,and the battery is appox.90 percent discharged(90 days).

Claude
000570

To check a battery, disconnect a
cable, charge it up and see if it holds the charge for a day or two 
(charges
usually tend to leak off with a bad battery)( Or just take it into a 
local
garage they'll usually put a tester on it and tell you, free of 
charge). Try
your meter again and see if it's holding around 12.5 volts or so.