Leisure Battery
The battery that supplies loads in the RV's living area such as lighting, the water pump, the fridge and the levelling system, designed to withstand repeated deep discharge. Its difference from a starter battery is that it is built to give a steady current for hours rather than a high current for a short time.
A leisure battery is made with thicker plates and more durable bonding of the active material. The aim is to be able to discharge and recharge hundreds of times; the aim of a starter battery, by contrast, is to deliver a few seconds of high current and refill immediately. These two design goals do not substitute for one another.
Typical leisure battery capacity in an RV is in the 80–200 Ah range and the nominal voltage is 12 V. In the lead-acid family, typically half of the label capacity is considered usable; that is, the practical energy share of a 100 Ah battery is around 50 Ah. In LiFePO4 the usable proportion is markedly higher.
The KTS200's 12 V DC legs create a short but noticeable load during levelling. Taking this load from the leisure battery removes the risk of flattening the starter battery and being unable to start the vehicle. If the leisure battery is weak the legs slow down or the movement is cut short; that is why the battery is expected to be fully charged before camping.
The context in which this term is used: RV automatic levelling guide