Calculating Charge Time - Schumacher Electric PWI70300A Manuel

Using the Battery Voltage Tester
Overview
This battery charger has a built-in voltmeter to test your battery's state of charge. The
charger does not have a built in load tester. As such, a recently charged battery could
have a temporarily high voltage due to what is known as "surface charge". The voltage
of such a battery will gradually drop during the period immediately after the charging
system is disengaged. Consequently, the tester could display inconsistent values for
such a battery. For a more accurate reading, the surface charge should be removed
by temporarily creating a load on the battery, such as by turning on lights or other
accessories for a couple of minutes before you read the display. Read it a couple of
minutes after you have shut the headlights off.
Testing Sequence: There are four basic steps required to test the battery state of charge:
1. With the charger unplugged from the AC outlet, connect the charger to the battery
following the instructions given in Sections 5 and 6.
2. Set the charge rate switch and the timer to the OFF position.
3. Plug the charger AC power cord into the AC outlet, following the instructions given in
Section 7.
4. Read the voltage on the voltmeter.
General Charging Notes
Fan: The charger is designed to control its cooling fan for efficient operation. It is normal
for the fan to start and stop when maintaining a fully charged battery. Keep the area
near the charger clear of obstructions to allow the fan to operate efficiently.
Voltage: The voltage displayed during charging is the charging voltage and is usually
higher than the battery's resting voltage.
12.

CALCULATING CHARGE TIME

Use the following table to determine the time it will take to bring a battery to full charge.
First, identify where your battery fits into the chart.
NR means that the charger setting is NOT RECOMMENDED.
Find your battery's rating on the chart below, and note the charge time given for each
charger setting. The times given are for batteries with a 50% charge prior to recharging.
Add more time for severely discharged batteries.
BATTERY SIZE/RATING
Motorcycle,
SMALL
garden,
BATTERIES
tractor, etc.
200 - 315 CCA
CARS/
315 - 550 CCA
TRUCKS
550 - 1000 CCA 80 - 190 RC
MARINE/DEEP-CYCLE
All manuals and user guides at all-guides.com
4 AMP
6 - 12 AH 1 - 2 hrs
12 - 32 AH 2 - 5 hrs
40 - 60 RC 5½ - 7¼ hrs
60 - 85 RC 7¼ - 9¼ hrs
9¼ - 17½
80 RC 8¾ hrs
140 RC 13½ hrs
160 RC 15 hrs
180 RC 16½ hrs
9
•
CHARGE RATE/CHARGING TIME
20 AMP
NR
NR
1 - 1½ hrs
1½ - 2 hrs
2 - 3½ hrs
hrs
1¾ hrs
2¾ hrs
3 hrs
3½ hrs
•
40 AMP 70 AMP
NR NR
NR NR
½ - ¾ hr 20 - 30 min
¾ - 1 hr 30 - 40 min
1 - 1¾ hrs 40 min - 1 hr
NR NR
NR NR
NR NR
NR NR