How can I tell if I have newer or older Bung flash carts ?
You have to take the flash cart apart which may void any warranty for it. If the chip farthest from the gold edge connector is a Altera EPM70xxSLC44 then you have an older version Bung flash cart. This chip draws massive amounts of battery power so don’t expect more than 1-2 hours battery life. Newer Bung flash carts draw power typical to commercial carts which usually allow ~10 hours battery life on a GB Pocket and ~20 hours on a GBC.