The Motobatt R&D guys are at the cutting edge of lithium battery development for motor cycles. Most bikers think that lithium batteries are expensive and used mainly in race bikes. Sure, the lithium units are expensive to buy initially, but in the long term their running costs are very much lower than lead acid batteries as they last a lot longer, have absolutely no maintenance, and you get a whole lot more bang for your buck. Consider this:
Be prepared to pay around 65% more up front for a Motobatt ProLithium model but take into account the long term savings of 70% in running costs (ie. cents per km), plus all the added benefits of higher power (ie quicker starting, brighter lights, loads of power for accessories etc), low weight, and much longer battery life.