Considering pulling the trigger on a NOCO battery charger mainly to have on the boat. Thinking the GB40 would be good enough for my 2 stroke 150 Pro XS. Anyone had to use one in a pinch and it came thru or opinions on how long they last?
You do realize that you're talking about a "jump starter" and not a charger? They are different.
I have had a GB50 since they were introduced. I have started a 5.3L V8 that would only click the starter solenoid on a cold day. Also cranked numerous smaller vehicles and other items like large lawn mowers, generators, etc. It has never failed to start what needed a boost. I've left mine in the truck for several months without charging and found it worked when needed. I take it out to charge occasionally, and it is typically topped off in an hour or so. Lithium technology has a very slow self-discharge rate.
I suggest you not leave it in the truck all day every day in the hot summer months. I had another brand fail when doing that.