i have a dead battery and decided to take it to the local garage to get it charged and they said it wont charge, they cheked that the alternator was charging the voltemeter and said that bosch batteries are c**p as they run out of charge very fast and do not like to retain voltage when charging, ive been looking arround the net and found a NUMAX and a YAUSA battery that fits, i was just wondering wether anyone had anything to say about this battery will i have another crap time with it running out in 3 weeks ? also looking at my battery ive seen that i must keep to the 12volts and 4ah but it has another value of 30A is this amps ? and how would buying a battery with a different A value change performance or would it not work ? i know im asking allot of questions on this forum but im fairly new to motorbikes and id rather be safe than sorry