11
SAFETYTROUBLESHOOTING
MAINTENANCE
OPERATION
PARTS
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

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-ChargeTester. Use the table below to
convert Voltmeter and State-of-Charge readings at room temperature to the appro-
priate Charge Factor. Then use the formulas that follow the table to determine the
approximate Charge Time.
its associated Charge Time in the table. Common battery types are:
• 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).
•NR means the charger setting is NOT RECOMMENDED.
• NA means not allowed. DO NOT charge at this setting

Charge Factor Table

Voltmeter Reading State-of-Charge
Reading Charge Factor
12 Volt Battery
12.67
12.45
12.03
11.86
24 Volt Battery
24.90
25.34
24.06
23.72
100%
25%
100%
75%
0
0.75
1
0.25
12.25 24.50 50% 0.50
Motorcycle
200 - 315
315 - 550
550 - 1000
Marine and
40 - 60
60 - 85
85 -190
80
140
160
180
10 AMP
NA
NA
1 - 2
2 - 3
3 - 7
3
5
6
7
6
10
2 AMP
2 - 4
4 - 10
8 - 11
11 - 16
16 - 35
15
26
30
33
20
32
Car and
Charge-Time (Hours)
Battery
Type

Charge Time Table for Batteries at 50% State-of-Charge

Battery Rating
and tractor
Truck
Deep Cycle
CCA
RC 20 AMP
15 AMP
NA
NA
1 - 1½
1½ - 2
2 - 5
2
3½
4
4½
NR
NR
Gel Cell
NA
NA
¾ - 1
1 - 1½
1½ - 3½
1½
2½
3
3½
NR
NR
40
80
95
105
40
80
6-12
12 - 32
AH
390
650