Charged leisure battery beeps when driving

Does anyone have any idea why - despite being charged - our leisure battery beeps when driving? It has only happened since having a new front battery installed so may well be to do with that. If anyone has encountered this before, do they know how to fix the problem. We are about to go on holiday in it and the last thing we want is to be beeped at all the time we are on the road!! Many thanks in advance.