Marine battery maintenance & care


Once activated, all batteries continuously release electrical energy and therefore self-discharge. When disconnected and at an ambient temperature of 10°C, this can be at a rate of up to 0.1 Volts per month. For every increase in temperature of 10°C, this rate doubles. For example, a disconnected battery at the very height of the UK’s summer could self-discharge at a rate of 0.3 Volts every month.

When in use or simply left connected to your vessel, the demands of electrical consumers such as alarm systems and trackers can increase the rate of discharge significantly.

Discharge damage

Irreversible damage can occur if sufficient care is not taken to maintain a battery. If a battery is allowed to deeply discharge, or if it falls below 12.40 Volts for an extended period of time, permanent damage will occur. Two of the most common causes are failure to maintain the battery when not in use and failure to check and charge the battery before and after each use.

Although many modern vessels feature a built-in battery monitoring system and intelligent charging facility while in use – ensuring appropriate care is taken while not in use is imperative to avoid damage caused by discharge.

Our range of YCX smart chargers can be used both on or off the vessel, ensuring your battery is maintained in optimum condition. Prior to use, it is important to ensure any smart charger is compatible with your specific marine battery’s technology. The Yuasa YCX5A12 is suitable for use on all types of battery, including AGM and EFB.

Periodic maintenance

If you are planning on removing the battery, ensure it is fully charged prior to storage. Periodically check the voltage is more than 12.40 V and connect to a smart charger if required. Recharge the battery every three months regardless of the voltage to refresh and mix the battery’s electrolyte solution.

Constant maintenance

If you are planning on leaving the battery on your vessel, ensure it is connected to a smart charger compatible for use with your specific marine battery. A smart charger with a pulse mode such as the Yuasa YCX5A12 will maintain your battery at 95-100% capacity by constantly monitoring the battery’s voltage and applying a pulse charge when required.

When removing the battery for maintenance, take the opportunity to ensure the battery terminals and clean and dry prior to reconnecting. Always lubricate the terminals after fitment with a suitable dielectric grease to prevent corrosion.