7
CHARGING VOLTAGES
ADDITIONAL INFORMATION
Charge Type
GEL
AGM / LEAD ACID
CALCIUM
LiON
BOOST
14.3V
14.0V
15.0V
14.0V
CHARGING
14.3V
14.7V
15.3V
14.4V
MAINTENANCE
13.5V
13.5V
13.5V
–
NOTE: Battery manufacturers sometimes specify charging voltages.
Not observing their charging instructions may void your battery warranty.
Deep cycle batteries
It is expected that this charger will be used to charge a deep cycle type auxiliary battery.
Deep cycle batteries are designed to provide battery power to run items like fridges and lighting in
caravans and campers.
It is generally accepted that the life of a deep cycle battery can be extended if it is not discharged
below 50% of its full capacity. A fully charged 100 amp battery in good condition should offer
50 amp hours of power without impacting on its normal life expectancy.
Your average compressor style fridge uses up to 5 amps. Over a 24 hour period it should use
approximately 30 amp hours. Therefore if the 100AH battery is operating only the fridge (and
receives no additional charge) it ideally will require recharging after 48 hours.
To replenish these 60 amp hours using a 20 amp DC-DC charger will require at least 4 hours of
driving. The last 10-20% of battery charging is slow, the closer it gets to 100%, the slower it is.
Undercharging a battery and discharging to below 50% can severely impact on life expectancy of
most deep cycle batteries.
Approximate state-of-charge
Average specific gravity
Open circuit voltage 12V
100%
1.265
12.65
75%
1.225
12.45
50%
1.190
12.24
25%
1.155
12.06
0%
1.120
11.89
The readings are taken at room temperature of 26°C (78°F); the battery had rested for 24 hours after
charge or discharge.
Voltage reading and specific gravity of electrolyte (lead acid batteries) can give an indication of your
battery’s state of charge.
