Seems to get mostly positive reviews. Bare in mind you can't let the voltage of these drop too far or it will kill the battery. They don't like cranking in REALLY cold weather and there have been some reports of them physically self destructing. These seem to be traits common to all brands lithium-ion batteries. It's good that the manufacturer specifically states they can be used in PWC (and thus tolerate exposure salt water... presumably). Have heard of other lithium-ion batteries crapping out if moisture gets into the casing.