Leisure Batteries – What Makes Them Different from Car Batteries
At first glance, a leisure battery and a car battery can look very similar. They’re often the same physical size, both are 12-volt batteries, and both store electrical energy. That similarity is what leads many people to assume they’re interchangeable — but they’re designed for very different jobs.
Understanding the difference matters, because using the wrong type of battery in a caravan can shorten battery life, reduce performance, and in some cases cause damage to the battery itself.
What a car battery is designed to do
A car battery has one primary purpose: starting the engine.
To do that, it needs to deliver:
A large burst of power
For a very short time
Then immediately recharge once the engine is running
This is why car batteries are rated by Cold Cranking Amps (CCA). They’re built to give a quick, high-current surge, not to be slowly drained over time.
Once the engine has started, the alternator takes over and the battery’s job is largely done.
What a leisure battery is designed to do
A leisure battery is designed for a completely different role.
In a caravan, the battery is expected to:
Power lights, pumps, control panels, and alarms
Deliver lower levels of power
Over longer periods
Often without immediate recharging
Instead of short, sharp bursts, a leisure battery is built to cope with repeated deep discharging and recharging, especially when you’re not on electric hook-up.
This is why leisure batteries are rated in amp-hours (Ah) rather than cranking amps.
Key construction differences
Although both types are lead-acid batteries (in most cases), the internal design is different.
Plate thickness
Car batteries use many thin plates to maximise surface area for quick power delivery.
Leisure batteries use thicker plates, which cope better with slower discharge and deeper cycling.
Thicker plates = longer life under leisure use.
Discharge behaviour
A car battery does not like being discharged deeply.
A leisure battery is designed to be discharged further — and more often — without damage.
Repeated deep discharges are one of the fastest ways to kill a car battery.
Why using a car battery in a caravan is a bad idea
It will work — briefly — which is why the myth persists.
But over time:
Capacity drops quickly
The battery struggles to hold charge
Failure happens far sooner than expected
In short:
A car battery in a caravan is a false economy.
Why leisure batteries are better suited to caravans
A proper leisure battery is designed to:
Cope with overnight use
Handle repeated discharge cycles
Work alongside caravan chargers and control systems
Provide predictable performance off-grid
This makes them far more reliable for touring, even if you mostly use electric hook-ups.
Common misconceptions
“A car battery is cheaper, so it’s good enough”
Cheaper upfront, usually more expensive in the long run.
“I’m always on hook-up, so it doesn’t matter”
Your battery still runs alarms, movers, and backup systems — and still cycles.
“They’re both 12V, so they’re the same”
Voltage alone doesn’t define how a battery behaves under load.
The takeaway
Car batteries and leisure batteries may look similar, but they’re built for very different jobs.
Car batteries: short bursts of high power
Leisure batteries: sustained, controlled power over time
For caravans, a leisure battery isn’t an upgrade — it’s the correct tool for the job.