Quick Tips To Ensure Your Boat's Batteries Are Healthy and Ready for Cruising

Summer is coming and the marinas are coming to life again. Many of our boats have sat through winter without being turned on, and some of you are finding that all is well, while some are finding that things aren't quite the way you left them. I want to talk about battery conditions and what should be checked and/or monitored all year round. Batteries are a chemical reaction contained in a box - this produces an electrical source of power that we use to power our boats.

During the colder months, we tend to use our boats less, if at all. Therefore, the batteries just sit on a very low charge, and don't get used. This is a depressing time for a battery as it needs to be used and discharged to keep it going. Discharging a battery is like exercise for it; it likes exercise but doesn't want too much of it or else it will collapses and die. With a good charging system behind our batteries, we can ensure that after every bit of exercise it can be restored back to great working condition.

There are many reasons why a battery may die. For one, it may die if it is discharged beyond its capacity and not given enough charge to restore it. Another could be that the battery isn't getting any exercise and its capacity decreases below a useable amount for the system. This could lead to an internal problem, causing the cells to short or break down. With the colder temperature during winter, the chemical reaction can slow right down inside the battery causing it to cease functioning all together. For whatever the reason may be, there are telltale signs to check for a bad battery, without all the gizmos a technician may carry. Here they are:

  1. A multi meter is a basic item that should be kept in your tool box onboard for checking electrical items. One easy test is to turn off all chargers and watch your battery monitor volt reading, or by putting your multi meter on each battery to read the DC volts. When you turn off your chargers, if the voltage of your batteries drops quickly from the charging voltage to a voltage reading below 12.8/12.7 VDC within a matter of 1-2 minutes, then there may be a problem with one of your batteries.
  2. A hydrometer is also an easy way to check your flooded battery cells to give you a reading as per their state of charge.
  3. Another simple test is just looking at your battery as it sits. Does it look out of shape? Are the sides warped significantly? Also, feel it by touch to see if it is warm or hot - this can be a clear indication it may be failing.

Recently I tested some engine batteries, and saw that the cabling directly connected to the battery positive and the surrounding cables had become black. A shorted cell inside the battery had caused it to fail but someone had still tried to start the engine with it, causing the cables to get really hot and discoloured. The battery was also hot and didn't cool for some time. Again, no technical gear was needed to see that this battery was in bad shape and needed to be replaced. So, if you are using your boat for the first time in a while, check your batteries quickly to see how they are doing. Check on them regularly; it doesn't take long and it could save you some trouble out at sea!