Schumacher SE-70MA - Manual (Page 11)

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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 any apparent battery filler caps. If, however, the battery
manufacturer/distributor recommends periodic checking of the electrolyte level
and provides access to the battery for water additions, the battery is probably
a conventional/low maintenance type.