Man’s best friend is his dog, right? If he’s trying to crank up a pair of engines, boating man’s best friends are his batteries. Unfortunately, batteries often get treated more like stray cats than favored family pets.
One reason for this is that many boat batteries are installed in cramped, nearly inaccessible locations. But make no mistake, they need care and feeding to provide reliable long-term service. In season, this care includes checking that connections are tight, clean and greased and ensuring the acid isn't boiling away. The following tips offer great battery care guidelines — for winter or any prolonged period of storage.
If You Haul Your Boat for the Winter
1. Charge It Up: Charge the battery, and then remove the negative cable. Let it rest for several hours before verifying its status.
2. Use Specific Gravity: Each cell should have a specific gravity of between 1.21 and 1.28, if you are using a hydrometer.
3. Use a Voltmeter: If using a voltmeter, a fully charged battery should read 12.5 volts.
4. Be Vigilant: Dream of springtime and either use a trickle charger/maintainer or check the charge monthly.
If You Store Your Boat in the Water
1. Stay Dry: Switch off all breakers except the one(s) for the bilge pump(s).
2. Make Rounds: Check the boat weekly, more frequently in rough weather and during power outages.
3. Keep It Up: Plug into shore power and keep the battery charged with your installed charger or a regulated battery maintainer.
4. Do Acid Test: Check the electrolyte level of flooded batteries and top off with distilled water — just enough to cover the plates.
Storing batteries on a concrete floor does not shorten their lives.