"They" could just as easily decide your old gas tank and connector was not safe enough and when you replace your hose, none that are compatible are available. It has happened.
I have not experienced that. I have a few of the hose connectors that go on the motor, and I started using metal gas tanks since the ethanol started ruining my plastic one. I've encountered various connections on tanks, but never one that stymied me for more than a few minutes. I just bought a NOS Suzuki 6 gal. metal tank, got a new hose with Suzuki connectors (similar to air hose connectors), and replaced the engine-side one with a Merc connector. Five minutes.
On the other hand, I've "re-celled" battery packs for various things including marine VHF handhelds, and done so that you can use them as they're designed you're still at the old battery technology, NiCd, for example, due to the radio and charger's electronics. And, there's no guarantee the battery pack packaging will survive the transplant. Don't ask me how I know.
What are the biggest issues with electric for transportation? Range, gauging, and recharging place and time. Range is getting better as battery technology evolves, but old systems don't necessarily accrue those benefits: it's more like scrap and re-purchase. (Note that electric cars' resale value is the lowest among classes of propulsion, i.e., gas, diesel, electric.) Gauging is troublesome. Users really want to know how far they can go before they have to recharge. Can they get there and back? Gauging is imprecise with electric, 'though people are working on sophisticated modeling both to estimate state of charge, using big data analysis techniques, and to estimate range using various models of battery behavior and models for range.
"One of the biggest obstacles preventing more widespread adoption of electric vehicles is “
range anxiety,” the fear of losing power and seeing your car shut down in the middle of a long-distance drive. Current technologies that estimate how much longer a battery will last still provide inaccurate measurements, because they use computer models that rely heavily on the driver’s recent behavior and don’t account for other factors."
Using Big Data to Fight Range Anxiety in Electric Vehicles - IEEE Spectrum
With gas, I just pick up the tank and I know if I can make it or not, and when I should think about getting some more gas. The behavior of gas engines and gas regarding range is very well known, intuitive.
Charging - where? Where can I plug this thing in, and how long will it take? At my marina there's exactly one EV charging parking spot. The first EV that gets there will park and plug in, and stay there all weekend. No one else can use it. Can you imagine if everyone drove and EV, and everyone had a Torqeedo? Sure, you can charge your Torqeedo battery on your boat, but as Larry points out, it draws 4A and will take a long time to charge (31Ah/4A very optimistically is 8 hours). On a mooring you'd be running the main engine a lot longer if you want to use it tomorrow
and keep your beer cold in your fridge. Solar - well, not if you arrive back at the boat in the evening and plan on using it in the a.m.
I have always thought that the only way this would work is if you could quickly swap your dead pack for a full one. That would require a very strongly enforced standard for packs for cars, I don't know about outboards.
I'm betting on "pocket" nuclear reactors.