Guidelines to make the boat batteries last longer
Posted on Feb 05th 2015
Very often the expensive boat batteries are mistreated and they lose their capacity within a couple of seasons. However, if you treat them well, a set of decent service batteries can last for five to seven years, depending on the type of treatment.
The following guidelines can help you to take proper care of your batteries and enhance their longevity.
1. Monitor the battery state
It’s absolutely necessary to manage the battery properly to ensure longevity. Discharging even the best deep-discharge batteries below 50 per cent of their rated capacity will dramatically shorten their life, while regularly flattening the battery can destroy it in a few months. Don’t underestimate the effect of this: over-discharge is the biggest single cause of battery failure. If your budget permits sophisticated battery monitor systems will measure all the charge put into and removed from the batteries and can calculate when they will next need charging, assuming a constant rate of power drain. In addition to this a simple voltmeter will give an indication of battery charge, as long as no load is being drawn.
2. Calculate your daily power use
A daily calculation of power usage is perhaps the most important element to ensure battery life. Daily power use can be estimated by multiplying the current in Amps of each electrical device on board by the length of time for which you typically expect to use it in each 24-hour period. Ideally the service batteries should be sized so that their amp hour (Ah) rating is three times larger than the boat’s daily electrical consumption.
3. Reduce your power requirements
This simple and cheap way can definitely lend your battery a long life. It’s as simple as not leaving lights on unnecessarily. Using low-energy LED bulbs can significantly reduce consumption, as will ensuring the fridge has plenty of insulation – 4in (100mm) is a minimum for efficient operation. Similarly, a couple of bottles of frozen water placed in the fridge at the start of each trip will significantly reduce the power needed to keep the contents cool.
4. Add a solar panel
Depending on the type of battery, there will be a self-discharge rate of around 1-3 per cent per month even if the boat is not in use. However, a cheap small solar panel is all that’s needed to account for this, which will again help to prolong their life. A small solar panel will eliminate self-discharge of batteries.
5. Fit a decent mains power charger
If you frequent marinas, plugging into their shore power supply is an easy way to reduce the drain on your batteries. In addition, a quality three or four-stage charger will ensure batteries are 100 per cent charged when you leave the following morning. Equally, for boats with access to shore power on their moorings a charger of a type that can be left permanently connected will ensure that the batteries are constantly pampered.
Motorshifi.com has provided you with golden guidelines to ensure the long life of your boat batteries. We do warmly welcome your tips, suggestions, ideas and views regarding the same.