I bought an izip Vibe e3+ 48v bike without a battery or charger. Instead of buying a replacement BL07 battery and charger for $600, I am thinking about getting a different higher AH battery and battery dock. Has anyone done this? Any suggestions? My major concern is the current cable going into the battery dock has the typical red and black power but it also has two smaller wires that I am not sure how to hook up to a new battery/dock that has just the two larger red and black connections. Any help is greatly appreciated.