"Grant Erwin" wrote in message
...
Tom Gardner wrote:

Mom's car, sitting for 2.5 years had to be moved. The Interstate 72 mo.
battery that was put in just before storage won't take a charge...no
surprise, I put another new one in. Rather than turning in the core for
$12
I will get it replaced under warranty. Is there any way to keep a new
battery on the shelf for extended periods of time? Should I keep it on
a
trickle charger? Is it an urban myth that sitting on concrete will kill
it?

I use (and love) a device called a "Battery Tender" when I let my
motorcycle sit
over the winter. It's about the size of a big wall wart and has lots of
ways you
can configure the end that attaches to your vehicle. My bike has a power
plug
that's always connected to the battery (intended for heated clothing) so I
just
plug it in there. The unit is completely intelligent and flat out works.
Every
guy I know that has a big motorcycle has one. It's exactly what you
need. - GWE

I have one called a "Battery Minder" for my motorcycle and it works well.
They have some additional circuitry in them that is supposed to help prevent
sulphation in the battery. So far, it seems to work very well (I also have
a
6 volt version I use for my gel-cell for my digital camera (I use external
power
when shooting the kids soccer games)). All secondary batteries will self
discharge over time -- some faster than others. One important detail to
remember (does not apply if you live in Florida etc.). A fully charged
car battery (lead acid) freezes at something like -70 F, HOWEVER,
a dead battery will freeze at about 32 F -- it is almost straight water
when it is dead. It will freeze and split the case so keep those batteries
charged in colder areas !!

mikey