when you say "spark is good" how do you know?
Do you have the cables and software?
How many hours are on this motor? It may be time and the least expensive move to replace all the coil packs and spark-plugs (and as is often noted, use the OEM plugs, and not an auto store's "will fits" in this motor PLEASE, not for you, unless you are who has to remove the plugs next).
Also this truck, as shovel_fx noted above, has an "assistant injector" that must work correctly or you get symptoms like these (mostly under load or acceleration), and there is a "Fast-tas" [idle air volume] learn-in procedure that has to be done with the software, that can also cause these symptoms if certain related components are changed.
AS far as what you are calling "the battery light", and beeping? Is this something that looks like a "d" cell flashlight battery? That is the swing out LPG tank bracket warning. Swing the LPG tank bracket back into place.