> > So what's the skinny on conventional batteries?? (Let's hear it from an
>> ex-salesman).
>
>Firstly, this applies to almost all battery manufacturers. The ones I sell
>(part time, student job) are manufactured by Exide, which supplies a LOT of
>batteries.
Exide make lots of batteries, under a variety of names. (That
includes the Crappy Tire store brands.) They also don't even make
all of their own batteries. A number of other companies make
batteries for them, including things sold under the exide label.
That's typical of the battery industry; there are many fewer battery
makers than brands, and some former battery companies that only
contract with various Asian factories. Within the products produced
by a company, their is often a wide range of quality.
> Anyways, like anything, they are cost-consciously engineered. The
>plates are thinner and weaker in order to maximise surface area, to boost
>CCA. The electrolyte volume ends up being very small, relative to the
Not exclusively the fault of the battery companies. Automakers are
under pressure to reduce weight and size, which means using batteries
that are more optimized for what their intended purpose is. Don't
forget, the purpose of an automotive battery is starting. Once the
engine is running, the alternator is sized to provide the power for
the entire electrical load. Providing a reserve for leaving the
lights on, using accesories with the engine not running, and so on,
is all secondary.
Starting requires lots of current, for a short period of time. The
rate at which a lead-acid battery provides current is dependent on
the rate the chemical reaction can take place, which is almost
linearly dependent on the surface area of the plates. The problem
with this is that the way you make a plate have more surface area
with the same amount of lead is to make it honeycombed or sponge
like. That means that they're more vulnerable to sulfation, which is
a process in which a sulfur compound fills the voids in the plates.
It's lead sulfate normally, but using tap water can cause calcium
sulfate. It's caused by undercharging or leaving a battery partially
charged for a long time. (and why you should make sure that the
batteries you buy aren't more than a couple months old.) The
batteries are also more sensitive to temperature changes -- which
speed plate flaking. The most common cause is deep discharging,
which gets you two ways. First, their is the heat generated by
discharging a battery, and if you've left you lights on or some such,
there is no cooling fan running. Second, is high-rate charging.
Charging a battery creates heat, whether you do it quickly or slowly,
but if you do it quickly, the heat is generated in less time, so
there's less time for it to be shed by the battery, and you get a
greater temperature rise. (The car can do this to itself, if you do
something like leave the lights on enough that you have problems
starting. The high-output alternator than brings the battery up to
charge quickly.
All of this is to say that the leading cause of battery failure is
abuse. Very many of the batteries that die early weren't maintained
(It's midnight. Do you know what your electrolyte level is?) were
repeatedly drained, were used in an inappropriate way (to run a huge
booming stereo. Or a winch....), or not clamped in place.
>
>One manufacturer that has resisted and still manages to put out a decent
>quality product seems to be AC-Delco. Unfortunately most of their stuff is
>side post, so, useless for us.
AC-delco batteries are made by Delphi. They make other brands, I'm sure.
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