Batteries have been around since the 1800s, and have inevitably come a long way since their first invention, allowing us to use them in a multitude of different scenarios. From slim line lithium batteries in mobile phones and portable electrical devices, to larger lead-acid batteries in cars, caravans, motorhomes, narrowboats and more, there is a huge range on offer to power all kinds of devices.

Naturally, the broad selection of batteries now on the market can make it a little confusing to decide on which one would be right for you. And when it comes to choosing the right leisure battery to install in your caravan, motorhome, narrowboat or any other leisure-style vehicle, it isn’t just a case of one size and type of battery fits all purposes. There are various aspects to consider when investing in a leisure battery to ensure you always have enough power on board to run your appliances and make life that little more comfortable.

While a lot of the attraction with caravans and narrowboats is the freedom it affords to “get away from it all” and even go “off the grid” if you like, there will undoubtedly still be a need to have some form of electrical power on board. Whether it’s to heat your hot water tank, power your fridge or simply charge your mobile phone, this is where choosing the right leisure battery is crucial. Pus, there is a significant difference in leisure batteries that will be getting occasional use to those that will be used everyday by people who are living on board their narrowboat or caravan permanently or for extended periods of time.

The differences between car and leisure batteries

While you may know a little about rechargeable car batteries if you regularly drive, you may not realise that these types of batteries are very different to those used in touring caravans, motorhomes or narrowboats, which are also rechargeable. Car batteries are often termed ‘shallow-cycle batteries’ or ‘starter batteries’ and are designed to deliver high power output over a short period of time to start the engine of a vehicle. Once the engine is started they will be rapidly recharged (usually by the engine’s alternator) to replenish the battery power for the next use. To prolong battery life, car batteries require regular charging and if left to fully discharge they are usually left with irreparable damage that affects their battery life considerably.

In contrast, a leisure battery is designed to provide a lower, but constant output over a longer period of time for 12-Volt electrical appliances on board. They are then recharged by either connecting to mains power supply, the leisure vehicle’s battery or to a special leisure battery charger; and unlike car batteries they can be discharged and recharged numerous times.  Although it is recommended to regularly charge leisure batteries and avoid allowing it to fully discharge, as a flat leisure battery can cause the charge depth to decrease and affect how well it holds the charge. Ideally, your leisure battery should never discharge below 80% to get the longest battery life from it, and once it goes below 50% it’s unlikely it will fully charge again.

Importantly with leisure batteries, you also need to know that there are different battery sizes available too, which offer different levels of power output for caravans, motorhomes and narrowboats.

Powering life onboard

Leisure batteries are listed with the amount of ampere-hours (AH) of power they give out. This is the optimum number of hours the battery will provide power for.  To ensure you have enough hours of power, you will also need to know how many amps each appliance uses to help calculate the best battery size. In most cases you will have multiple devices, so you will need to combine all the amps to establish which battery is the most appropriate.  Most appliances will tell you how many amps they are, but if they don’t a simple formula can be used:

Watts  / Volts = Amps

From the total amps of your devices, you can then calculate the amount of battery amp-hours you can expect from your battery. This can be basically calculated with this formula:

Amps/amp-hours (of the battery) = Output hours

A basic example of this would be if you had a 12V caravan kettle with a standard 120-watt current it would use 10 amps. Therefore with an 85AH battery it would last for 8.5 hours and with an 110AH it would run for 11 hours at optimum usage.

Naturally, these are very basic formulas and other factors can affect the amp-hours your battery provides, such as the age of the battery and the length of time you use it – realistically you aren’t going to be boiling your kettle for an hour at a time!

Another factor is how often you plan to use your vehicle. For example, if you intend to use a caravan just for short weekend trips and occasional use then you should find an 85+AH battery offers sufficient power output for your 12V devices on board with regular charging, either via mains hook up or leisure battery chargers.

Inevitably, those looking to live in static caravans or narrowboats, will need a much greater volume of amp-hours to power all the devices for longer and may also need to account for no access to mains power at times.  Thus calculating the number of amps your appliances use has even more importance to help gauge how much battery power is needed.

Extended use will require a leisure battery with a much greater power output to cope with constant use and more demand. Therefore larger sized batteries such as 110+Ah or ideally 125+Ah, should provide enough power to ensure that living onboard a narrowboat or static caravan is comfortable and convenient.

It’s also crucial to assess the size of your caravan, motorhome or boat in relation to the leisure battery, as well as the number of electrical gadgets and devices you have on board. The larger the vehicle or vessel, the more likely it is there will be electrical devices that require a bigger power output to cope with a greater capacity – this could be a bigger water heater to accommodate more people, a larger fridge or simply more electronic devices. Furthermore, the more time you are spending living on board will increase the demand on the battery to cope with a longer draw of power.

Ample power

How long a battery will last will depend on how much power is drawn from it without it being charged and how well it’s looked after. Understandably, no rechargeable battery will last forever, but there are certain things you can do if you’re planning on living onboard a narrowboat or in a static caravan to preserve the life of your battery for longer.

Firstly, an important part of maintaining your battery life and performance is to keep it charged up to the right level.  This is often easier to do if you’re living on board, as unlike occasional users it won’t be sitting dormant for long periods of time, which can deplete battery life and charge depth. To maximise your battery life it’s always a good idea to ensure it doesn’t go below 80% charge and where possible keep it fully charged when not in use. This will all work to helping maintain a good battery performance and a longer service life.

A great way to ensure your battery stays optimally charged without draining on mains power hook up costs or causing overcharge damage to batteries is to invest in a trickle charger or combination charger as opposed to a standard charger. The trickle battery charger is designed to slowly charge the battery up as and when it’s needed, and will automatically switch off once the battery has a full charge, which will help to maintain the battery life. The standard charger offers a quicker recharge, but must be switched off manually to prevent overcharging and damage to the battery components and chemicals. As you would expect, the combination charger offers both functions, giving you more options for charging, which can be helpful if you’re spending a lot of time aboard.

At Alpha Batteries, we offer a huge selection of leisure batteries for all kinds of use, whether you’re an occasional camper or caravaner or you’re looking for a more permanent power supply for a static home or moored narrowboat. While it can seem confusing calculating your appliances amps and amp hours, we offer an expert service and advice to help you accurately calculate your usage requirements and ensure you find the most suitable battery for life on board.