Why it matters
Leisure batteries degrade gradually - by the time you notice weak lights, it's often already well past its best. A proper check catches this before you're relying on it off-grid.
How to do it
- Check the resting voltage with the van unplugged and unused for a few hours (a fully charged 12V lead-acid battery should read around 12.6-12.7V).
- Look for any swelling, corrosion at the terminals, or a strong smell - signs of a failing battery.
- If it won't hold charge overnight after a full recharge, it's likely time to replace it.
How often
At the start of the season and before any longer trip off-grid.
Rough UK cost
A voltage check is free with a simple multimeter; a replacement battery is £120 - £450 fitted.