Leisure Batteries

Leisure Batteries />

26/05/2020

Introduction

BPZ believes in addressing the needs of all our customers present in the battery market. Usually in everyday life, when we say battery, we are referring to automotive batteries which are normally found in cars.

This generalisation can make it confusing for consumers when trying to deal with a different type of battery.

Today, we will discuss the distinctions between the standard automotive and a leisure battery.

To do so, we need to start by defining a leisure battery and then comparing its purpose to that of an automotive battery. We will further explore leisure batteries by identifying and explaining their types and applications. To conclude our discussion we will look at some of the best practices related to the maintenance and safe use of leisure batteries.

What is a leisure battery?

The natural question for most people when they hear the words "leisure battery" is what is a leisure battery?  A leisure battery is a specially designed battery capable of delivering a steady amount of current for a long period of time to lower levels of discharge, than an automotive battery. 

This design differentiates leisure batteries from the standard automotive battery. The leisure battery is more commonly used in caravans and motor homes and marine applications as the power source. We will look at their role in greater detail in the applications section below.

Purpose and properties of leisure batteries

Having defined the leisure battery, we have a general idea of its purpose. To understand it further we need to look at some of the properties of the leisure battery. Leisure batteries fall under the broader category of deep cycle batteries while, similarly, automotive batteries fall under the broader category of starting, lighting, and ignition (SLI) batteries. This essentially means that if we study the properties and behavior of deep cycle and SLI batteries, we will have a better understanding of the difference in the purpose of both leisure batteries and automotive batteries.

Let’s first look at the SLI batteries. Their purpose in cars is to provide the primary source of power required to start the car. The secondary purpose of an SLI battery is to power the electronics when the engine is not running. To achieve its purpose of providing a high current, it needs a high current carrying capacity. This is achieved through thinner plates so that more plates can be accommodated in the battery to increase the surface area. Its design is such that it is recommended to recharge after a discharge of 5%. When the car engine is running, the alternator recharges the battery.  A deep discharge will reduce an SLI battery lifespan as it will damage the battery plates in time dependent on the depth of discharge and the frequency (This is known as cycle life).

On the other hand, deep cycle batteries are, in many ways, the opposite of SLI batteries. Their purpose is to provide a steady discharge current over a long duration.  They achieve this purpose through thicker plates which means lesser surface area. This results in a lower current capacity but the current produced by deep cycle batteries is steady and can last for a longer duration. As the name deep cycle suggests, deep cycle batteries can discharge to a greater extent and then be recharged with less damage to the battery.

All batteries should be recharged (full recharge cycle) as soon as possible after a discharge.  The discharge and recharge process is known as a cycle.  The deeper the depth of discharge and the frequency of this action is directly proportionate to the life of the battery. Frequent deep cycles equal less life. It is an incorrect myth that batteries should be fully discharged before recharging. We will gain further clarity regarding the purpose of leisure batteries when we see the applications of leisure batteries in the coming sections.

Types of leisure batteries

A leisure battery can be differentiated from another leisure battery in two ways. It can be classified on the basis of its type or it can be categorised on the basis of the standards set by the National Caravan Council (NCC).

We would look at the types of leisure batteries from both perspectives.

In terms of types, leisure batteries can be classified as:

Lead-acid (Wet Vented) batteries

Also known by other names such as flooded batteries and semi-traction batteries, the lead-acid batteries remain the most common (and the cheapest) type of leisure batteries in the market. It comprises of lead plates placed in sulphuric acid which acts as the electrolyte for the battery. It has removable caps which means that you can monitor and top up the electrolyte if needed. The tradeoff for its low cost is its need for regular maintenance. Monitoring electrolyte levels is important because if the top of the lead plates is not covered in the electrolyte, the plates may be damaged. Also, a discharge of more than 50% may permanently damage the battery.

Lead Acid (Wet Sealed) batteries

Sealed batteries are similar to vented batteries, in terms of traits, to the standard lead-acid batteries. The main difference is the fact that its caps are sealed which means that it saves the user from the hassle of regular maintenance, so it's often considered as the maintenance-free battery. Generally, sealed batteries are more expensive than lead-acid (wet vented) batteries.  The addition of calcium as an additive to wet lead acid batteries enabled manufacturers to seal the batteries as well as increasing the performance.  

VRLA (Valve Regulated Lead Acid) batteries

  1. AGM Batteries

AGM (Absorbed Glass Mat) batteries are defined as sealed maintenance free batteries. Their construction is different. The difference lies in the fact that the electrolyte is absorbed into a fiberglass mat. This allows a controlled interaction between the electrolyte and the active material on the plates. Battery performance is greatly enhanced, when it comes to discharge and recharge capability. Rechargeability is improved by three and a half times when compared to wet batteries.  Some AGM batteries (Leisure type) may perform a dual role as in auxiliary power supply as well as cranking ability.  Even AGM SLI batteries have a better cyclic performance than wet batteries.

  1. GEL batteries

Gel batteries are similar to AGM batteries with one key difference. The fiberglass mat is replaced by a pasty gel. This change has its advantages and disadvantages. The main benefit is that you get a better performance and cycle life. Disadvantages include:

  1. Higher pricing compared to AGM batteries
  2. Higher sensitivity to voltage and temperature when charging
  3. May not be used in a cranking application

Lithium batteries

Lithium batteries are already commonly used in laptops and phones but now they have shown their potential as a leisure/solar battery. Their primary benefit is that, compared to lead-acid batteries, they are lightweight yet have almost twice the energy density. They can manage discharges of around 80 to 100% of their full capacity at full power.  They may also operate in PSOC (Partial State of Charge) and may also be left discharged for longer periods of time when compared to lead acid batteries.  Most Lithium batteries have the ability to be recharged at a C.5-C1 rate, meaning for example: a 100AH battery may be recharged by a 100Amp charger in 1 hour.

Applications of leisure batteries

With regards to caravans and motor homes, a leisure battery's main application is to provide electricity for powering appliances like the fridge/freezer, lights, TV etc. and power outlets which may be used to charge your phones and laptops etc.  

Their application becomes more significant in locations where an electric hook-up point is not available since they are the primary source of power in that case. Even in camping sites with electric hook-up points, it is recommended to have a leisure battery as a back-up power supply in the event of a power cut.

Leisure battery maintenance and safety measures

Like with any other battery, there is a set of best practices to follow when it comes to handling a leisure battery.

  1. Ensure that the battery is correctly sized for the application
  2. Ensure that the correct thickness of cable is utilized, as well as the correct length
  3. Ensure tight firm connections
  4. Ensure that the battery is not over discharged according to its specifications
  5. Recharge the battery fully after use, using the correct size battery charger (Minimum charging current should be at least 10% of the ampere hour capacity of the battery EG: a 100AH Battery – 10 Amp Charger)  
  6. Never store a battery in a discharged state
  7. Always recharge a battery fully before storage
  8. Ensure that the charger you use has the capability to supply the correct – equalization and / or absorption voltage as well as the correct float / trickle charge voltage.

Safe handling is equally important when it comes to leisure batteries. Ensure batteries are correctly mounted with a reliable hold down clamp. Whenever the battery is inspected, safety equipment like eye goggles and gloves should be used given the corrosive nature of the acid found in batteries.