Schumacher Electric SE-40MAP Owner's Manual page 10

NOTE: Not all switches and LED's are available on all models.
Ammeter
The Ammeter indicates the amount of current, measured in amps, that is being drawn
by the battery. As a battery takes on a charge, it draws less current from the charger.
Correspondingly, the meter will show less current being drawn by the battery. When the
current stops decreasing, the battery is charged. The start area of the meter indicates a
high rate of current being drawn from the charger. When cranking an engine, the meter
needle will be at the extreme right side of the start area. The 2 amp charge rate may
indicate some activity on the meter, although the meter does not have the resolution
to display this low rate. For the 2 amp charge rate, a triangle has been provided. Its
accuracy has been calibrated for use with small batteries.
• Percent of Charge
The percent of charge scale is intended as a visual aid to help simplify reading the
state of charge. It is scaled for use with the 6, 10, 12, 15 or 30 amp charge rate only.
For the 2 amp charge rate, use the triangle. The percent of charge is based on the
current drawn by the battery. For this reason, accuracy will vary with the size and
battery type. Typically a 28 ampere hour gel cell battery will draw less current at the
end of the charge cycle than a 140 ampere hour wet cell battery. This means that the
indication for a fully charged large battery may be slightly less than 100%.
Battery Type Switch
Use this switch to set the type of battery to be charged.
• SLI – These initials stand for Starting, Lighting and Ignition, which are the three basic
functions which a battery has to perform on all normal vehicles. This battery type is
usually used in cars, trucks and motorcycles. These batteries have vent caps and
are often marked "Low Maintenance" or "Maintenance-free". This type of battery
is designed to deliver quick bursts of energy (such as starting engines) and have
a greater plate count. The plates will also be thinner and have somewhat different
material composition. Most Maintenance Free Batteries are SLI, otherwise known
as Flooded, Regular or Standard Batteries. Regular batteries should not be used for
deep cycle applications.
• Deep-Cycle – Deep-cycle batteries are usually marked as "Deep-Cycle" or "Marine".
Deep-cycle batteries are usually larger than the other types. This type of battery has
less instant energy but somewhat greater long-term energy delivery than regular
batteries. Deep cycle batteries have thicker plates and can survive a number of
discharge cycles.
• AGM – The Absorbed Glass Mat construction allows the electrolyte to be suspended
in close proximity with the plate's active material. In theory, this enhances both the
discharge and recharge efficiency. Actually, the AGM batteries are a variant of Sealed
VRLA (valve regulated lead acid) batteries. Popular uses include high performance
engine starting, power sports, deep cycle, solar and storage battery. AGM batteries
are typically good deep cycle batteries, and they deliver best life performance
if recharged before the battery drops below a 50 percent charge. If these AGM
batteries are completely discharged, the cycle life will be around 300 cycles. This is
true of most AGM batteries rated as deep cycle batteries.
GEL
• – The Gel Cell is similar to the AGM style because the electrolyte is suspended,
but different because technically the AGM battery is still considered to be a wet cell.
The electrolyte in a GEL cell has a silica additive that causes it to set up or stiffen.
The recharge voltages on this type of cell are lower than the other styles of lead acid
battery. This is probably the most sensitive cell in terms of adverse reactions to over-
voltage charging. Gel Batteries are best used in VERY DEEP cycle application and
may last a bit longer in hot weather applications. If the incorrect battery charger is
used on a Gel Cell battery, poor performance and premature failure is certain.
When antimony is known to be one of the materials used in the battery's construction,
that battery is conventional/low maintenance type.
Some low maintenance batteries have a relatively smooth top without
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