I recently(three weeks ago) jumped into the lithium battery boat. I bought this for my polaris rzr:
https://www.ebay.com/itm/WPS-Featherweight-Lithium-Battery-HJTX30L-FP-IL-HJTX30L-FP-IL/152493396095?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Initial impressions are good. Has plenty of reserve capacity for the radio. LiFePo(lithium iron phosphate) batteries are considerably safer than Lithium ion batteries. There are some great test videos showing overcharge and over discharge torture tests, and the cells used in these can take a 200amp short per cell. I will be trying this battery out in my riverboat as a starting battery, then probably ponying up for a large one.