Caravan and motorhome owners planning on a long trip always try to ensure everything is in working order before embarking. One common question that pops up in this regard is ‘how to test a leisure battery?’ A leisure battery is going to power up every appliance inside the caravan, including crucial components such as a phone charger and GPS. A leisure battery failing midway can bring disastrous consequences.
Fortunately, checking the leisure battery’s health is quite an easy task. With the information provided here, you can diagnose your leisure battery health yourself and find out if it is time to replace the battery or not.
Leisure Battery Overview
A leisure battery is the primary source of electricity inside a caravan or a motorhome. Appliances such as lights, electric kettles, ovens, fridges, communication equipment, and everything else are powered by a leisure battery. It is different from the car starter battery. The only purpose of the car batteries is to start the vehicle. Leisure batteries are deep-cycle batteries and can provide power for an extended period of time.
To provide this electrical power, leisure batteries need to be charged themselves. This can be done through various means such as AC mains, electrical hook up, solar panels, wind turbines, and more. When planning a trip, it is important to determine beforehand how you would be charging the leisure battery during the duration of your vacation.
Checking health is just as important, especially if the caravan or motorhome will spend time in remote locations. In case the leisure battery falls into trouble midway, it can be nearly impossible to find the right replacement on short notice in remote locations. Additionally, losing electrical power for crucial components can lead to a very difficult and even dangerous experience.
How to Test Your Leisure Battery?
Testing a leisure battery’s health is a very easy task. The health is determined by measuring the battery voltage, whether it is a car battery or a deep cycle battery such as the leisure battery. To measure the voltage, you will need either a voltmeter or a multimeter. The voltmeter provides only the voltage readings whereas a multimeter reads additional things such as current and resistance along with the voltage.
The healthy battery voltage depends on the type of battery. To know what voltage your battery should have, check the manufacturer’s guide provided with the battery.
How to Check a Battery Voltage Using a Multimeter?
In order to measure the voltage you need to
- Disconnect the battery from the circuit
- Set the knob of the multimeter to a higher voltage than the rated one and choose DC supply. For instance, if your battery is rated at 13.5V, choose 15V on the dial.
- Now touch the VΩmA end of the multimeter to the red battery terminal (positive terminal).
- Then, one by one, touch the COM end of the multimeter to the black terminal (negative terminal) of each cell of the battery one by one.
Using this method, you can find the voltage of the individual cells as well as the voltage of the entire battery (sum total of individual cells).
How to Check a Battery Amperage Using a Multimeter?
Checking the amperage ensures that the battery can fulfil the current requirement of the load condition. The amperage of leisure batteries is rated in Amp hours, which is the number of hours for which the battery can supply 1 A current.
To check the amperage of the leisure battery:
- First, disconnect the battery from the circuit.
- Turn the multimeter knob to a higher current than the rated value.
- Make sure that you choose DC supply.
- Connect the red probe to the Ampere port of the multimeter, and the black probe to the COM port.
- Connect the other end of the black probe to the battery’s negative terminal and the red probe to the positive battery terminals. The current will be displayed on the screen.
- Compare this value to what the manufacturer lists on the label.
How Often Should You Test a Leisure Battery?
The frequency of your battery checks will vary depending on what type of battery you have. For instance, in the case of LiFePO4 batteries provided by Eco Tree Lithium, the expected lifetime easily goes over 10 years.
Therefore, you will require very rare battery checkups if you are using the battery in the right way. For these batteries, checking once every three to four months and charging them accordingly is a good idea.
However, for lead-acid batteries, there is a good chance that the battery can fail just after a year or two. Additionally, these batteries don’t hold charge well. Therefore, lead-acid batteries can require very frequent checkups. These batteries should be checked before every major trip.
What Voltage is Too Low For a Leisure Battery?
As mentioned earlier, the exact discharge voltage of a leisure battery can vary between batteries.
In most cases, any voltage below 12V is too low for a leisure battery and it will damage the cells.
In such a case, it is advisable to disconnect the battery immediately and charge it with a smart battery charger.
An important thing to note is that damage caused due to extremely low volts like this is irreversible, so it is best to avoid such a deep discharge state.
What Voltage is Too High For a Leisure Battery?
Many people are not aware of this but all batteries can get damaged from overcharging as well. Just like over-discharging, overcharging also causes permanent damage to the cells.
Any voltage over 14.4 can cause overcharging damage to the cells. Typically, the battery becomes fully charged at a voltage of 12.9V.
Leisure Battery Testing Tips
Here are some tips that will ensure safety and better results when testing a leisure battery:
- Ensure that you are using DC voltage mode on the multimeter instead of the AC voltage when testing leisure batteries (or any other type of battery including car battery). This is because every battery always outputs DC.
- The multimeter knob should always have a greater range than what the possible results can indicate. For instance, if the voltage can go up to 14V, the multimeter should be at 15V or 20V.
- Disconnect the battery completely to check the battery voltage and current ratings. Remove any covers and let the battery sit idle for an hour if the battery was in use recently.
- Charge the battery fully and then check the health of each cell individually with the multimeter. In case the values of a particular cell differ from the rest, it is an indicator of a damaged cell or dead cells. It is recommended to replace the entire battery even if a single cell is damaged because it causes strain on the other cells raising the probability of complete battery failure.
- Every battery has a specific fully charged and fully discharged voltage. When you buy a leisure battery, these values will be mentioned on the battery labels and/or the manufacturer’s user guide provided with the battery. It is important to use these values for reference over any industry standards or generic recommendations.
Signs That Your Leisure Battery Requires Replacement
Besides the damaged cells, there are other signs as well that can signal that it is time to replace your battery. One good criterion is the on-load performance of the battery.
When you apply a load on the battery (such as the oven or the water pump), if the voltage drops to a discharged value (such as 10V), it is time to replace your battery.
While it can seem like a complex and technical task at first, checking if you have a good battery. The benefit of learning the process is that once you get the basics right, you can apply it to all types of batteries like your car battery.
It is always a good practice to invest in a high-quality battery to ensure that you don’t have to do frequent checks on it. Eco Tree Lithium is the leading leisure battery provider in this regard.
These batteries come with a 6-year warranty along with an inbuilt battery management system. The battery management system has multiple protection measures such as overcharge and over-discharge protection, keeping your battery healthy for a decade or two.
Frequently Asked Questions (FAQs)
Here are the answers to some commonly asked questions regarding leisure battery testing:
1. What is the difference between a battery tester and a multimeter?
A multimeter is a device that can tell the accurate voltage and current characteristics of any electrical device, including a battery. A battery tester is designed for the sole purpose of testing a battery’s performance characteristics under load.