I'm planning on goin with the oddessy pc1200 it's a direct replacement with just moving a few wires ... if u own a xt and up model u have a 30ah battery and dps/base models have a 18ah battery they both have around 350 cold cranking amps... the oddessy pc1200 is a 42ah deepcycle battery ... the first 5 seconds of turning the key it produces 1200cca up to 10 seconds produces 1050cca... after turning more than 10 seconds it runs 550cca .... it can drain its self completely and be recharged to 100% up to 400 times in its life cycle ... also can be mounted anyway u would like besides inverted ... Optima also makes a very good direct replacement but threw many reviews the the oddessy has it out edged plus a lil cheaper and also cheaper than running a dual battery setup and having to buy mount and run an isolater, buying a battery mount and also purchasing a second battery .... for under 250 bucks I believe it's the route I'm going to run ... some may rather run a dual setup just to have peace of mind if ur listening to ur audio set ups and runnin ur lightbars u have a separate battery to start back up to go home on ... but to safe some weight and keep it clean ima gonna try the deep cycle route and see how it goes