A good leisure battery is an essential component in most motorhomes. It provides power to lights and accessories in the van’s living accommodation without flattening the vehicle battery and leaving you stranded.
The first thing to note is that a leisure battery is not quite the same as a vehicle battery. Vehicle batteries are designed to provide a lot of power for a short time, and then to be quickly recharged. This is what happens when you start an engine and then drive for a while.
Leisure batteries, on the other hand, are designed to be discharged more slowly and over a longer period of time. This is what happens when you camp without electric hookup and use your leisure battery to power lights, television, laptop computers, etc..
There are three main types of leisure battery generally available:
- Open lead acid: These are the cheapest, and many people believe, the best – traditional lead acid batteries with removable caps and a vent to allow hydrogen gas to escape during fast charging. Note that they will need topping up occasionally and do need venting for safe use. Lead acid batteries are also available in sealed form, where the gases are recirculated and turned back into liquid, rather than being vented. The downside of this is slower charging, but sealed batteries don’t need venting, a possible advantage in a motorhome.
- Gel: These are basically lead acid batteries in which the liquid has been reformulated as a gel. This has some advantages if you think your battery may be turned upside-down, but I am not sure what the point of it is otherwise. Gel batteries are also much more expensive and charge more slowly.
- AGM: Another ‘maintenance free’ battery type that is supposed to offer superior performance (for its size) to regular open lead acid batteries. AGM batteries are much more expensive, must be charged more slowly and cannot be topped up.
It may seem as if I am being unreasonably critical of Gel and AGM batteries. However, it should be noted that lead-acid batteries still dominate the worldwide vehicle (and boat) battery market. The reason for this is that they are cheapest and best and no one has yet found a convincing reason to switch to another technology.
Open lead acid batteries (those with vents to allow gas to escape) can be charged faster than any other type and will give good performance at the lowest possible cost. They aren’t maintenance free, however – they do need topping up with distilled water occasionally, especially if charged fast.
The only reason I can see for choosing sealed lead acid, gel or AGM batteries is if they cannot be vented or (in the case of gel batteries) if they will be turned upside down for more than a couple of seconds at a time.
My experience is that open lead-acid batteries work well as leisure batteries as long as they are kept charged and topped up – what’s your experience?
Note: To read more about batteries and charging, have a look at these two links, both from the websites of makers of high quality battery chargers: