Battery advice please

Bighammerfan

Hi. I have a 2003 Coachman Amara 450/2 which has a 85ah battery on it. I am having a Powrtouch mover fitted and they say I need a 110ah. I phoned them and they said that a 100ah would be ok. My question is, although I can get a 100ah which is the same physical
size as my 85ah, will a 110ah fit in the locker ? I cant measure mine as its in storage miles away.

 

Thanks  Alan