Schumacher SC-7500A 用户手册

13

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 de-

pends 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 11). 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 

measured in amps. This charger 

provides charge rates of 2A, 12A 

and 30A. The 75A rate is for engine 

start only. The

 2A rate is for charg-

ing smaller batteries such as those 

used for motorcycles and garden 

tractors. Such batteries should not be 

charged using the 12A or 30A rate. 

The 12A and 30A rates are for charg-

ing larger batteries. In the 30A mode, 

the charger begins at a low charge 

rate and increases the charge rate if 

it is determined that the battery can 

accept the higher 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 BATTERY % 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 bat-

tery 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.