Schumacher ProSeries 00-99-000742 - Manual (Page 13)

12
BATTERY PERCENT AND CHARGE TIME
This charger adjusts the charging time in
order to charge the battery completely,
efficiently and safely. The microproces-
sor automatically makes the necessary
decisions. However, this section includes
guidelines that can be used to estimate
charging times.
The duration of the charging process
depends on three factors:
1.
Battery State – If a battery has only
been slightly discharged, it can be
charged in less than a few hours. The
same battery could take up to 10 hours
if very weak. The battery state can be
estimated by using the built-in tester
(see page 10). The lower the reading
the longer charging will take.
2. Battery rating – A higher rated battery
will take longer to charge than a lower
rated battery under the same conditions.
A battery is rated in ampere-hours (AH),
reserve capacity (RC) and cold cranking
amps (CCA). The lower the rating the
quicker the battery will be charged.
3. Charge rate – The charge rate is mea-
sured in amps. This charger provides
charge rates of 2A, 15A and 40A. The
125A rate is for engine start only. The
2A rate is for charging smaller batteries
such as those used for motorcycles and
garden tractors. Such batteries should
not be charged using the REGULAR
BATTERY setting. The 15A and 40A
rates are for charging larger batteries.
In the regular battery mode, the charger
begins at the 15A rate and increases
the charge rate if it is determined that
the battery can accept the 40A rate.
All charging modes will decrease the
charge rate as the battery approaches
maximum charge.
After the charging process has started, the
digital display can be used to determine
charging progress by selecting the BAT-
TERY % mode.
There are some important facts to keep in
mind when charging a battery.
• When the display indicates 77%
charged, the battery has been charged
enough to start most vehicles and has
already been charged as much as by
many other battery chargers.
• When the display indicates 85% charged,
the battery has already been charged at
least as much as by most other battery
chargers.
• The battery % shown in tester mode is
an estimate based on the battery voltage
and the Battery Council International
scale. The battery % shown in charger
mode is an estimate of the relative charge
in the battery compared to the charge it
should have if the charging process is
allowed to complete.
• The battery % shown in tester mode can
be used to estimate the relative charge
time. The lower the % shown, the longer
the charge time for a given battery.
• The battery % shown in charger mode
is an indication of the relative progress
of the charging process. The higher the
battery % displayed, the less charge time
remains.
• The more a battery is discharged, the
faster it absorbs charge from a charger.
That means that the battery % increases
faster at the beginning of the charging
process than at the end. In other words,
it takes longer for the battery to absorb
the last few percent of charge than the
first several percent.