Is it possible to use a small solar panel to trickle charge a leisure battery? if so any advice would be welcome

Hi Bryn.

The answer is yes. I have a small 10w solar panel and a cheap 30 amp PWM charge controller wired to a 70 A/h Halfords leisure battery. We only use it in winter though, after the battery has been charged in the 1st instance for maintenance. I recommend this little site on solar panel charging to give you an estimate of charging times based on a battery discharged to 50%.

https://footprinthero.com/solar-panel-charge-time-calculator