Need Battery advice for mobile sound system
I'm looking for a suitable battery to power a mobile music system.
The system will be made up of a single 12V car amplifier (between 100 to 200W output), powering a single large speaker (rated at around 100W).
The setup is to be carried by a person (walking around with music pumping out of him), and I am therefore looking for a battery that is considerably lighter than a car battery.
I am hoping to be able to power the speaker for between 2 to (ideally) 4 hours, whilst keeping the cost to a minimum.
Could you offer me any advise as to what type of battery would suit my needs?
Thanks in advance for your time and advice,