11
APPENDIX A — CHARGING TIMES
To calculate the approximate charging time required to fully charge a battery, it is necessary to determine the
specific gravity (or, percent of battery charge) using a hydrometer. Use this technique if battery vent caps can
be removed. Check each cell. If there is one cell with a very low specific gravity compared to the other cells,
there is probably a shorted cell in the battery. Replace the battery.
The following chart converts hydrometer readings into percent of charge values.
SPECIFIC GRAVITY
PERCENT OF CHARGE PERCENT OF CHARGE NEEDED
(HYDROMETER READING)
IN BATTERY
BY BATTERY
1.265
100%
0%
1.225
75%
25%
1.190
50%
50%
1.155
25%
75%
1.120
0%
100%
Refer to the chart below for approximate charging times.
PERCENT OF CHARGE
75%
50%
25%
0%
2 AMPS
6.5 HRS
12 HRS
NR***
NR***
10 AMPS
1.8 HRS
3.0 HRS
4.5 HRS
6 HRS
20 AMPS
1 HRS
1.5 HRS
3 HRS
3.5 HRS
40 AMPS*
NR**
NR**
NR**
NR**
* For Charging Batteries 80 to 100 AH
** Not Recommended for more than 1 hour
*** Not Recommended because of the 18 hour charge time
The times shown in the chart above are approximate and refer to an average automotive battery. For smaller
batteries, the charge time should be adjusted using the formula shown below and adding 1 hour to the time
calculated.
To estimate charging time for a discharged battery, divide the AH rating of the battery by the charge rate selected.
This is the number of hours required to recharge the battery. For example, a 50 AH (12 volt) battery is
discharged (10 volts). How long should it be charged at the 20 Amp rate. Divide the 50 AH by 20. The answer
is approximately 2.5 hours. Always round up the charge time by 10% to ensure full charge. In most cases, bat-
tery recharge times will vary depending on the age and condition of the battery. Smaller batteries should be
charged at a lower rate (2 Amps) and add an extra hour to charge time.
APPENDIX B
Your VEC093 charger is NOT recommended for float charge applications. It is intended for single application
charging and as such, turns off COMPLETElY at the completion of a full charge cycle and will NOT turn
itself back on even if the battery voltage drops. If vehicles, RVs, snowmobiles etc. are going to be stored for
extended periods of time, we recommend that you charge the battery at a low to medium rate on a bi-monthly
basis to keep it fresh. Avoid high rate charging for stored batteries.
VEC093
A062003
