On 12/11/2014 11:37 PM, micky wrote:



snip


I felt guilty about ruining a new battery. I could return it and pay
little for a replacement, but with Priority Start, I've gone almost 2
years, never wasting more than 10 seconds in the morning. (Once the
car starts in the morning, I have no more problems that day, even in the
winter.)




It's not likely that you "ruined" a new battery, even if you
over-discharged it.


When a battery is discharged so completely that it will not recover to a
point anywhere near 12 volts...it /can/ be recovered.

One problem often seen is that automatic battery chargers need to see at
least 10 volts or so in order for them to start.


What needs to be done with an over-discharged battery is to place in on
a manual charger or a variable voltage charger.

With a manual charger, some current will flow and though the ammeter may
initially show almost no current, eventually the battery will /usually/
recover. In some cases I've seen batteries run so low that it was
required for me to crank the voltage up rather high in order to get the
current to start flowing.

If using a variable voltage charger, it's important that the current be
closely monitored because as the battery begins to recover, the current
will initially rise.


In all the years I was in the battery industry, I was able to recover
all over-discharged batteries if they had not been sitting in that state
too long.

Should a battery sit over-discharged too long ( 3 -6 months) stage
three sulfation will inevitably have set in and any such battery would
only be partially recoverable at best.