Snap-On BATTERY CHARGER PLUS Manuel D'instructions page 12

cALcuLAtinG cHArGE tiMES
the chart Method
Use the following table to more accurately determine the
time it will take to bring a battery to full charge. First, identify
where your battery fits into the chart.
• Small batteries – motorcycle, garden tractors, etc. – are
usually rated in Ampere Hours (AH). For example: 6, 12,
32 AH etc.
• Batteries in cars and smaller trucks are usually rated in
Reserve Capacity (RC), Cold-Cranking Amps (CCA), or
both.
SMALL
Motorcycle, garden tractor, etc.
BATTERIES
CAR/
TRUCKS
MARINE/DEEP CYCLE
the Hydrometer or Electronic Method
To find the time needed to fully charge your battery,
determine the battery's charge level with a hydrometer or
electronic Percent-of-Charge Tester. The following table will
help you convert hydrometer readings to percent of charge
values.
SPEciFic PErcEnt oF
GrAVitY cHArGE
1.265 100%
1.225
1.155
1.120
When you know the percent of charge and the Amp
Hour (AH) rating of your battery, you can calculate the
approximate time needed to bring your battery to a full
charge.
To convert Reserve Capacity to Amp Hours, divide Reserve
Capacity by 2, and add 16:
Example:
Amp Hour Rating = Reserve Capacity + 16
notE: The reserve Capacity can be obtained from the
battery specification sheet or the owner's manual.
EEBc500-int-Z
BAttErY SiZE/rAtinG
200 - 315 CCA
315 - 550 CCA
550 - 1000 CCA
PErcEnt oF cHArGE
nEEdEd
0%
75% 25%
25% 75%
0% 100%
2
• Marine or deep-cycle batteries are usually rated in
Reserve Capacity (RC).
• NR means that the charger setting is NOT
RECOMMENDED.
Find your battery rating on the chart below and note the
charge time given for each charger setting. The times
given are for batteries with a 50-percent charge prior to
recharging. Add more time for severely discharged batteries.
cHArGE rAtE/cHArGinG tiME in HourS
(unless otherwise stated)
4 AMP
6 - 12 AH 2 - 4
12 - 32 AH 4 - 10
40 - 60 RC 11 - 14
60 - 85 RC 14 - 18
85 - 190 RC 18 - 35
80 RC 18
140 RC 27
160 RC 30
180 RC 33
To calculate time needed for a charge:
• Find the percent charge needed. (A battery at 50%
charge that will be charged to 100% needs another 50%
(.50)).
• Multiply the Amp Hour rating by the charge needed (.50)
and divide by the charger setting (4, 15, or 60 amps).
• Multiply the results by 1.25 and you will have the total
time needed, in hours, to bring the battery to full charge.
• Add one additional hour for a deep-cycle battery.
Example:
Amp Hour Rating x % of charge needed x 1.25 = hours of charge
Charger Setting
100 (AH Rating) x .50 (charge needed) x 1.25 = 3.125 hours
20 (Charger Setting)
100 x .50 x1.25 = 3.125
20
You would need to charge your 100-Ampere Hour Battery
for a little more than three hours at the 20-Amp charge rate
using the above example.
11
• •
15 AMP 60 AMP
NR NR
NR NR
60 - 90 min. 20 - 30 min.
90 - 120 min. 30 - 40 min.
2 - 3.5 45 - 60 min.
105 min. NR
2 hrs, 45 min. NR
3 NR
3.5 NR