Batteries are both simple in theory and complicated in care. It is best to keep a battery at full charge and equalize the battery as recommended by the manufacturer. Both of these are difficult to do when the boat has no access to 110V to power. Some pocket cruisers have an outboard motor with an alternator; but the alternator doesn’t put out many amps at the RPMs used to move the boat in and out of the marina. Another limitation in caring for a battery using an outboard is we sailors don’t run the motor long enough to fully charge the battery. Yes, solar is an option; but on a 17-foot boat there isn’t room for a solar panel of enough size to quickly charge nor equalize a battery.
The three common batteries available are: wet cell, Absorbed Glass Mat (AGM) and gel cell. Lithium Ion batteries are coming onto the market requiring special controllers & chargers, are extremely expensive and have some ‘new technology’ teething problems –
- Lithium is a completely different animal
- New Lithium-Ion Batteries … Could Be A Problem On Boats
- Replacing Batteries? Do Your Homework First
If you really wish to get into the ‘nuts and bolts’ relating to caring for your boat’s battery Practical Sailor magazine has a series of articles on battery use and care. These articles provide excellent detail and reviews of how different batteries perform. To access many of these online articles you do need a paid subscription.
The demonstration Sage 17, AIR BORN, has been using a ‘wet cell’ battery for the past four years. When I returned from my July trip to Pocket Yacht Palooza in WA State, and Cruiser Challenge in CA I set about charging the battery. After 24 hours the battery was not coming back to a full charge and upon further inspection was bubbling off electrolyte at a high rate.
A charging wet cell battery will release small amount of bubbles (hydrogen). This is normal. The battery sounding like a boiling tea kettle shows something is going very wrong. One cause of the charger is sending to much voltage to the battery. I tested the charger with another wet cell battery with no problems. I believe the charger is working correctly so my diagnosis is that one, or more, of the ‘boiling’ battery’s cells has failed.
In this post’s beginning paragraph I stated, ‘It is best to keep a battery at full charge.’ This has rarely been done with AIR BORN’s battery as she is never kept in a location where she has easy access to 110v. How it usually goes is AIR BORN returns from a trip, or after being in her slip at the Lake Dillon Marina, I park her near the boat shop, drag an extension cord out and charge the battery for a couple of days. Yes, I am guilty of battery abuse.
After four years of use this battery has done well. One can expect a battery to last for 4-5 years. I do wish it would have lasted longer; but I feel that it was abused and held up well after being heavily discharged and being left in a partially charged state.
The replacement battery will be a gel type. I’ll report on how well this battery performs under AIR BORN’s challenging conditions.