[MikeS100]

Thanks Iain. Just to clarify, I'm not suggesting removing the old battery, that would stay in place, I'm just not sure if it is ok to leave the charger on permanently while on site to provide power to the lights, I'm not sure if it's designed to work like that. In the past I would run the lights on battery power alone and then when the battery got low flick the charger on to charge it back up for a bit and then turn the charger off again to go back to battery power.