Checking Your Batteries with Captain Chris

6 volt batteries wired in a series to equal 12 volts.

When was the last time you checked the water level in your flooded batteries? Do you have maintenance free gel cell or AGM batteries instead? How many and what type of batteries do you have aboard? When checking your batteries there are many things to consider.

How Many Batteries are Aboard?

Depending on the size of your boat this can be a large inventory of batteries installed in many locations throughout the hull.

• Dedicated Cranking battery for your propulsion engines.
• Separate dedicated cranking battery for your generator.
• Deep cycle batteries for your house bank and inverter
• More batteries for your thruster and anchor windlass.

Flooded batteries only

As you are checking your batteries, the charger may have evaporated the water and you will need to fill or “top” them off. To do this you will need distilled water and I recommend a regulator battery filling jug. This special jug has a spring loaded nozzle. Fill the special jug with distilled water and push the regulator down into the liquid cell. The water will fill to the appropriate level. You will know when the jug has filled the battery to the proper level because the gurgling sound will stop. Be careful because the water in the batteries is actually acid. Wear old clothing and protective glasses in case of splashing.

All Batteries

Grab your battery cables and pull and shove on them to make sure they are secure. Look at all fittings for any corrosion when checking your batteries. Make sure your posts are covered with insulators protecting the battery from a short circuit.  (see photo) Take a good look at the shape and condition of the battery itself. Is it bulging or hot to the touch. If so, turn off the battery charger and get out of that area until it cools down. Then disconnect and replace. Find out why this happened as it could be an old battery or a faulty charger.

Some batteries require special chargers

You may not mix a flooded battery and an AGM battery on the same charger unless the charger has a separate programmable output for each different style of battery.

Want to Learn More?

Maintain your batteries so your boat is ready to go when you are. But, if you are not comfortable checking your batteries yet, Ask Captain Chris and we’ll walk you through your first time. 772-205-1859…Better yet, join us at Introduction to Boat Systems, a hands on 2-day seminar in Vero Beach FL.