Marine Battery Charger Basics
A good battery charger protects your battery investment.
Standard chargers have been around for a long time. They are designed for intermittent use to charge wet cell batteries. Do not use these for multiple charging cycles in regularly used electrical power systems.
Most of today’s chargers are microprocessor controlled “Smart Chargers” with multi-stage charging patterns for today’s deep cycle batteries. They are safer, smaller, lighter and more energy efficient. Not all chargers are created equal, so be aware of compatibility of your battery type and charger.
Most of today’s chargers are microprocessor controlled “Smart Chargers” with multi-stage charging patterns for today’s deep cycle batteries. Manufacturers have designed single charging units to be used with multiple battery systems. They can charge from 2-6 batteries and adjust for each individual battery’s condition.
We strongly recommend chargers built in the USA. They offer great quality, durability and price.
Basic 3-Stage Charging Sequence
Manufactures are advancing charging sequence to as many as 8 steps and use algorithms for diagnoses. However, the basic three stage charging sequence is generally used and is as follows:
The first “Bulk Stage” charges the battery to about 80%. Charger current is held constant as voltage increases. You will want to verify manufacturer’s recommendations, but a properly sized charger will give the battery as much power as it will accept and not raise a wet battery over 125F, or an AGM or GEL battery over 100F. A general rule is not to exceed charger above 25% of battery capacity in amp hours.
The second “Absorption Stage” charges the battery the remaining 20%. Charger runs at a higher absorption voltage and decreases the power until the batter is fully charged. Sometimes called “equalization stage”.
The third “Float Stage” maintains a low constant voltage to less than 1% of battery capacity. This allows the battery to maintain a full charge without damage for long periods of time.
eBoat Marine offers quality chargers built in the USA.