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11
SAFETY
OPERATION
MAINTENANCE
TROUBLESHOOTINGPARTS
CALCULATING CHARGE TIME
Battery Rating Method
Use the following table to more accurately determine the time it will take to fully charge a
battery that is initially at 50% State-of-Charge. Identify your battery type and its associated
Charge Time in the table. Common battery types are:
Motorcycle
200 - 315
315 - 550
550 - 1000
Marine and
6-12
12 - 32
12 AMP
NA
NA
1 - 2
2 - 3
3 - 5¾
2½
4½
5
5½
2 AMP
2 - 4
4 - 10
8 - 11
11 - 16
16 - 35
15
26
30
33
Voltmeter Method
To find the time needed to fully charge your battery, determine the battery’s charge level
with a voltmeter or electronic State-of-Charge Tester. Use the table below to convert
Voltmeter and State-of-Charge readings at room temperature to the appropriate Charge
Factor. Then use the formulas that follow the table to determine the approximate Charge
Time.
Car and
Charge-Time (Hours)
Battery
Type
• Small batteries, motorcycles, garden tractors, etc., are usually rated in Amp-Hours
(AH).
• Car and truck batteries, usually rated in Reserve Capacity (RC), Cold Cranking
Amps (CCA), or both.
• Marine, or deep cycle batteries, usually rated in either Amp-Hours or Reserve
Capacity (RC).
Charge Time Table for Batteries at 50% State-of-Charge
NA = Not Allowed. DO NOT charge at this setting
Battery Rating
and tractor
Truck
Deep Cycle
AH
CCA
RC
40 - 60
60 - 85
85 -190
80
140
160
180
75 AMP
NA
NA
NA
NA
NA
NA
NA
NA
NA
Charge Factor Table
Voltmeter Reading
State-of-Charge
Reading
Charge Factor
12 Volt Battery
12.67
12.45
12.25
12.06
11.86
6 Volt Battery
6.22
6.34
6.12
6.03
5.93
100%
50%
25%
0%
75%
0
0.50
0.75
1
0.25
40
80
95
105