The thing with batteries is that there are many better uses for them. Morale, once you have the skill you need, really only matters if really high or low. Flashlights, Welders, Bionics if you have the mods, and so many other things can use them so I think they are decent enough as is. I know that once I get a welder I never have enough batteries.
Unless you're scavenging is purely nocturnal, flashlight use will be few and far in between. Even without a vehicle welding rig you won't go through
that many batteries in regular vehicle maintenance, and construction is a special case. The Battery System bionic will chew through batteries, true, but you have plenty of other options: Solar Panels, Internal Furnace, Ethanol Furnace, etc.
If you don't have enough batteries, it's because you aren't taking advantage of the myriad opportunities to obtain them. Disassemble cell phones for 200 batteries, unload every radio, doll, soldering iron, geiger counter, and extra flashlight/mp3/hgs you find. If you desperately need more, you can craft them in batches of 100 out of empty soda cans and vinegar. I routinely leave thousands of batteries at my shelters.
Not to mention that drugs have other uses besides morale boosting, such as getting an extra boost of speed or ignoring pain.
Fair enough. They also have fairly severe malus - painkillers slow you down, for example, and the addiction system in this game is extreme. Mp3 players have no such drawback, for 15 batteries I can have 50 morale straight up. No time cost because turning it on seems to be a non-action. Just turn it on, go about your business, and turn it off again a few turns later.
I'm not saying they need to be removed, but if listening to music for a few minutes put you in a better mood than smoking cannabis or getting drunk people wouldn't do drugs. It seems very backwards to me. Either capping the morale boost lower (say, 20) or making it much more gradual (so more like 50 batteries to get the full morale boost) would make it at least make sense.