Marine Solar Battery Charger Tips

Equipping a boat with a marine solar battery charger makes a lot of sense as evidenced by the many boaters and yachtsmen that choose to do so. The following are good to know tips about choosing and using solar powered marine battery chargers

Match the Marine Battery Charger to the Batteries You Use

Most marine batteries are capable of deep discharge-recharge cycles. There are several types of deep cycle batteries available for boaters and yachtsmen. You need to know the following about your batteries before you decide on the solar powered marine battery charger you want to purchase.

• The voltage rating of the battery; most marine batteries are rated as nominal 12V


• The capacity of the battery in Amp-Hours (Ah)


• The battery type: flooded battery, gel cell or AGM

Choosing a Marine Solar Battery Charger

Money spent on a smart marine battery charger is money well spent. Buying a marine battery charger is a non-recurring event; a good charger can save you the need to buy new expensive batteries because the old ones were not timely and properly re-charged. What can you expect from a properly chosen solar marine battery charger?

• It should match the voltage rating of your batteries


• If your battery bank has more than one battery, the battery charger should have independent DC outputs to re-charge each battery individually


• The charger current should supply a current that is 10-20% of the capacity. For example to re-charge a 100Ah battery, the charger should output 10-20Amp. Too much current will cause gassing and heating, too small current will cause lead sulfate crystals build–up on the electrodes. Both mechanisms will shorten the life of the batteries and degrade the batteries performance


• A marine battery charger must comply to UL 1236 and to the FCC regulations


• The charger should withstand the vibrations incidental on board


• The charger should provide for automatic temperature compensation to prevent over-charging and to sense the battery voltage


• Smart marine chargers are equipped with self diagnostic and LED indicators. They can profile the charge cycle by “a shifting gear mechanism”. Initially they start with the highest current (Quick mode), then they shift gear to a lower current to bring the battery to full charge and then they shift gear to the lowest trickle charge current to compensate for the battery no-load discharge current.

Taking care of a Solar Marine Battery Charger

The solar panel must obviously be exposed to sunlight on board. The charger itself must be secured in a water proofed casing, well ventilated. Keep all DC terminals clean and greased and all cables tightly connected.

More Reading

Many boaters and yachtsmen opt for AC appliances. For operating AC appliances you need DC to AC converters called solar inverters

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