Leisure Battery Draining- Reasons, Diagnosis, and Solutions

Many caravan and motorhome owners complain about leisure battery draining very fast. This is a very undesirable phenomenon that can also bring danger and inconvenience if the battery unexpectedly runs out of juice in the middle of a trip.

This article will have a detailed discussion on why your leisure battery is draining faster than it should. Additionally, it will also provide ways to diagnose if your battery is working correctly, and solutions to fix the leisure battery drain issue.

What is a Leisure Battery?

What is a Leisure Battery

A leisure battery is the powerhouse of a caravan or motorhome. It runs all the appliances in the vehicle, such as lights, oven, refrigerator, navigation equipment, fans, and every other thing. These batteries are very different from a car starter battery since the purpose of the latter is only to start the vehicle.

Why is My Leisure Battery Draining Fast?

Why is My Leisure Battery Draining Fast?

Leisure battery drain problems can occur due to various factors. These factors can occur singlehandedly or in combination with one another. The different factors leading to leisure battery draining are:

Battery Age

The age of the battery is one of the most common factors that contribute to battery drain. Batteries do not last their entire lifetime in perfect condition, regardless of its type and make. As they become older, the rate of discharge increases gradually. Therefore, if your battery is nearing its expected lifespan or is well past it, a faster battery drain is to be expected.

Faulty Battery

If you are not using an old battery but it is still draining very fast, it can be a sign of a faulty battery. Batteries are generally not repairable if there is internal damage or fault. Faulty batteries can be determined by using a voltmeter, or by contacting the manufacturer.


Temperature plays a vital role in affecting battery drain. In case of extreme freezing temperature, a fully charged battery will cease to function (at around -50℃). If the battery is uncharged, it can freeze and cease to function at just -1℃. Frozen batteries do not work again. Therefore, it is recommended to charge the batteries completely in the winter.

Battery Charger

Battery Charger

The quality and health of a battery charge are often overlooked by owners of leisure batteries. Battery chargers affect the quality of charging, which in turn affects the lifespan and battery health. If the battery charger isn’t of good quality or in good condition, the battery will be constantly undercharged. In the long term, this means that the health of the battery will get compromised leading to faster drains.

Connected Appliances

Many times, users forget to turn off the appliances connected to the battery which continues to drain the charge. If the battery seems to be draining without a reason, it is a good idea to check if you left any light on or the fridge running.

Heavy Appliances

Heavy appliances constantly draw power at a larger rate, leading to considerably faster draining of the battery. If you are using multiple such appliances or any single such appliance for a long time, you can expect battery drain issues. Some of these heavy appliances are:

  • Fridge
  • Water pump
  • Alarms
  • Outdoor lights
  • Fan
  • Oven
  • Microwave
  • Television
  • Electric Kettle
  • Radio

Alternator Diode Problem

The alternator is the device in a vehicle that charges the leisure battery and the starter battery through the engine. Alternators have diodes so the battery power does not flow back reversely into the alternator. If there is an issue in the diode, the battery will start to drain inversely. These issues require diagnosis and repair by an automotive electrician.

Improper Battery Storage

If the battery is not in use and is left in a discharged state for a long time, the battery’s health is adversely affected. This can lead to faster battery drain in future operations.

Signs of a Bad or Dying Leisure Battery

If the leisure battery shows the following signs, it can be an indication that the battery is dying and requires replacement or consultation with the battery manufacturer:

Pre-Startup Signs

  • Turning the ignition on does not start the gauges, lights, and/or other indicators.
  • The battery requires jump start every other week or so.
  • If the engine is idling, the battery dies out within 30 minutes or less of powering general accesories.

Startup Signs

  • During battery startup, the lights dim.
  • Starting is difficult if the battery is run on idling for long hours.
  • Problems in the winter.
  • Ignition requires more than three turns.

Driving Issues

  • Accessories such as lights or radio shut down midway for no apparent reason.
  • Accelearating the vehicle dims the lights or powers down the accessories.

Additional Signs

  • Swollen battery.
  • Unusual smell.
  • Discoloration.
  • Leaking fluids from the battery.
  • Crack in the battery body.
  • Terminals have a crack or a break.

Diagnosing Battery Drain Issues

Diagnosing Battery Drain Issues1 Min

A common question that users ask is ‘how to diagnose battery drain issues?’ The solutions are quite simple and do not require any detailed technical knowledge. Here are the different ways to diagnose issues causing the battery drain signs:

Before Battery Startup

1. First things first, check all the terminals and electrical connections. Sometimes, charging or discharging issues are nothing more than a broken wire at someplace. Make sure that every connection is tight, secure, and insulated.

2. Using a battery tester, voltmeter, or multimeter, check the voltage between the terminals of the battery. The battery manufacturer provides the ideal voltage rating for the battery. If the tested voltage is lower than the ideal rating, the battery is undercharged. In this situation, it is recommended to use an external charger to charge the battery or power it through an electrical hookup.

3. Once the battery is fully charged, use it to see if it is holding its charge well. In case the battery is losing its charge even without powering any appliance, it is indicative of a faulty battery.

Using Habitation Master Switch

The habitation master switch is supposed to turn off power to all the appliances connected in a motorhome. Once your leisure battery is charged, switch off the master switch. If the battery power drain still occurs, either there is still an appliance wrongly wired draining continuous power from the battery or there is a battery issue that requires technical inspection.

How to Prevent Your Leisure Battery From Draining Fast?

How to Prevent Your Leisure Battery From Draining Fast?

Once a leisure battery starts to drain faster because of internal damage or end-of-life, there is no fix to it and it will require maintenance. However, there are certain steps that you can take as a motorhome owner to prolong its life span and prevent rapid battery drain. Here are some of these recommendations:

Healthy Charging Habits: Proper charging habits lead to a healthy, functioning battery. The particular type of charging methods can vary between lead acid batteries and lithium battery cells. However, some general tips remain the same, such as charging the battery to full capacity. A fully charged battery is less susceptible to declining health. For most batteries, it is a good idea to recharge them whenever they reach a 50% charge level.

Solar Panels and Wind Turbines: Secondary charging methods such as solar panels or wind turbines are a great way to keep your leisure batteries charged and healthy. Solar panels provide a trickle charge to the battery which is great for filling up those discharges caused by small power consumption such as lights or radio.

Voltage Checks: The battery voltage between open terminals is a great way to find out if the battery is fully charged, discharged, flat but recoverable, or damaged beyond recovery. Do periodic voltage checks with a battery tester, voltmeter, or multimeter. The fully charged and discharged voltage can vary among different battery types and make.

Appliance Management: Using too many heavy equipments at the same time will accelerate battery drain. Therefore, managing the appliance equipment is a recommended practice. For appliances that consume too much power, such as a microwave, using them to the minimum is a good idea.

Electrical Hook-Up: After using the leisure battery, it is recommended to charge it using an electrical hookup. For heavily discharged leisure batteries, charging should be done through AC mains or mains hookup. While secondary charging methods like solar panel and wind power can charge leisure batteries, the charging is too slow and takes a very long time (from days to weeks).

Conversion Kit: Electrical batteries provide DC power and charge through DC power. However, electrical mains provide an AC current. Therefore, it is important to use a conversion kit when using mains charging. Mains chargers usually come with this conversion kit inbuilt. Never connect a DC battery directly to AC mains without a conversion kit.

Regular Motorhome Running: The alternator of your motorhome is designed to charge your leisure batteries. However, for that purpose, your car needs to be running. Therefore, start your motorhome every few days and take it for a drive. This will keep your leisure battery as well as your engine battery in a healthy condition.

Using OEM Equipment: When it comes to prolonging the life of your battery, there is nothing better than following the manufacturer’s recommendations to the word. One of the foremost example is using the original battery charger or a replacement approved by the manufacturer.

Where to Buy New Leisure Batteries?

Where to Buy New Leisure Batteries?

Eco Tree Lithium is the best online marketplace for sourcing new leisure batteries. Being the provider of top quality Lithium Iron Phosphate (LFP) batteries, Eco Tree Lithium provides a six-year warranty with each of its products. This means that phenomena such as battery drain or a duff battery are out of the question. Additionally, there is a battery management system with a control panel that monitors every aspect of the leisure battery. This makes the battery well-protected against most risks and damages.


Maintaining leisure batteries is not a tough science. Battery drain is a common problem but it is more probable in old batteries or lead acid batteries. Avoiding it is easy, you just need to follow the prevention tips mentioned above and use a good-quality lithium battery. Following these precautionary measures can keep your new battery in a good shape for a long time.

Frequently Asked Questions (FAQs)

Here are the answers to some common questions that people ask regarding leisure battery drain:

Does a leisure battery drain when not in use?

Yes, leisure batteries tend to drain even when they are not in use. Most caravans and motorhomes tend to draw a minor current of about 100 mA (or even more) while everything seems to be switched off. This can occur due to multiple reasons, such as the vital indicators or monitor system running. While this current seems to be very minor, it can easily lead to a completely flat battery in two weeks time. The best way to prevent it is to disconnect the battery completely or using the battery isolator switch if provided with the battery.

How long should a leisure battery hold its charge?

How long your battery stores its charge depends on the type of battery. Lead acid batteries are notorious for losing their charge in a short period of storage. Lithium batteries hold their charge very well, depreciating only 2% to 4% in a month of storage. As a rule of thumb, you should charge these batteries every three months even in storage to keep them healthy.