About Your Boat Batteries...
(Part 2 of 2)
Sulfation
Have you ever had a
battery that seems to work well but “dies” much more quickly than
expected? The problem may be a battery that is heavily sulfated
– often the result of only light use (being discharged by only 15% or
so). The sulfuric acid has become concentrated on the battery’s bottom
and sulfate crystals have begun to form. And even though a multi-meter
will indicate that all is well in terms of voltage, the capacity of
the battery has become severely reduced. Sure, the battery will work just
fine, but it will die much sooner than normal. There are certain chargers
that have a setting that will temporarily boost the charging voltage for a
brief period of time, causing a mixing of the electrolyte, and dissolving
the crystals. The process is called equalization and can be done –
depending on the manufacturer – about once a year. But beware: this
should only be done on wet cell batteries; this same process can ruin
other types. And you will need to make sure that you disconnect the
batteries from the electrical system to prevent the higher voltage from
damaging other equipment.
Maintenance
Batteries have come a
long way since the 60’s. Back then, most – if not all – wet cell
batteries were dry to start with. In the storeroom of the gas station at
which I worked, there was a large box with a plastic bag filled with
electrolyte – sulfuric acid. I found out it was acid the hard way; in
filling a battery, I once managed to splash the electrolyte all over my
pants. I didn’t realize the power of the stuff until my work pants got
washed. They looked as if I had been shot by a machine gun – the one leg
was nothing but holes! Now there is an incredible variety of batteries
that are available for every imaginable use: marine starting & trolling,
auto, agricultural, industrial). They all have at least one thing in
common: they need to be maintained to some degree – even the “maintenance
free” types. They will lose their electrolyte during normal use and need
to be checked; all need to be recharged. Most of us still use the wet
cell types for marine applications, although there are essentially three
distinct types of lead acid batteries manufactured for marine
applications, and any one type can be designed and built for either
starting or deep cycle applications. These types are flooded acid, gelled
acid, and Advanced AGM (Absorbed Glass Mat). The gelled acid and AGM
types are essentially maintenance free since they are sealed. But because
of this, be very careful when recharging them. They are also more
expensive but do have their advantages. The most important thing for the
flooded acid variety is to keep them full. Top them off with distilled
water whenever possible; minerals in tap water can contaminate the
electrolyte. Keep the terminal clamps clean and free of corrosion; coat
them with anti-corrosion spray or even petroleum jelly. Check connections
and keep them tight; watch for frayed wires and replace them. And for a
few bucks spent at your local auto parts store, a
Battery Hydrometer
– used to
check the specific gravity (concentration of acid) is a good investment.
It is a great way to determine if one of the cells is bad. If the
difference in specific gravity is 30 points or more… it’s time to replace
your battery!
Checkup and Storage
Whether or not your boat
is stored for the season in a warm garage or out in the cold, your best
bet is to remove all batteries and bring them inside. A fully charged
battery with a perfect electrolyte level can probably withstand
temperatures down to zero degrees without freezing. But the colder it
gets, the more easily a battery can discharge, and therefore the more
easily it can freeze at higher temps. If even one of the cells freezes,
the battery is shot! Fully charge them about once a month over the winter
and they will be ready when you are in the spring. Try to keep them off
of concrete floors is possible and cover the terminals to help prevent
discharge. The last thing you want is a dead battery on the launch ramp
on opening day, or a dead trolling motor battery.
With summer now
officially here, I hope that most of you have either fished the opener
somewhere or are, like me, chomping at the bit to head to the lakes once
again. Make sure to check your batteries before you head
out. And when next October rolls around, you will perhaps remember a few
things from this article and make sure to take proper care of those very
important pieces of equipment: your batteries. See you
On the
Lake!
R. Karl
rkarl@onthelake.net
Read "Boat Batteries Part 1"
