Bought new charger for charging up the leisure batteries we use in the fencers. Keeps blowing the 20amp fuse in the front. Would the charger be faulty or is it the battery? Have successfully charged some but others it doesn’t seem to like. Some of the batteries are pretty dead (staff didn’t work out the old charger wasn’t working for a while 
). Can I put a bigger blade fuse in it?? Thanks
). Can I put a bigger blade fuse in it?? Thanks
