Radioisotopes decay, the process of decay generates heat, for example americium-241 decays with an initial 0.114W/g - for centuries. Simply using a few hundred grams of this and a brutally inefficient solid-state thermoelectric generator, a voltage regulator & some shielding we can create a more-or-less forever phone charger the size and weight of a house brick!
Now, this might need a little refinement. I suggest a burly exterior with a robust handle, think small ammo case. There's easily room in the package for a couple of rechargeable cells, which, given the 24/7 nature of the output could charge constantly, allowing the charging of up to 4 phones for 6hrs/day! Careful design of the insulation properties of the casing would allow for a hot spot on the upper surface, for coffee. In addition, the whole unit, in the bottom of a sleeping bag might be a useful companion in chillier environments.
So, how do we sell these? Obviously, the market is military, which means the cost per unit can be pleasingly astronomical. But initially, we don't sell them, we give them away. So, at one of the big defense "conferences", the type with the really cool green/grey stuff is on show, we target a few specific types of people. What you need, is a military rank that is just about in the middle, say Captain ish. You give a nice RTG-phone charger to this Captain, name deeply engraved in the case, possibly a GPS tracker and other security features to prevent casual theft and you wait.
The choice of rank is critical, they need to be low enough so they're mixing it with many ranks so that the RTG- charger is seen, and after remote deployment, jealously coveted. Not so low that "I think I'd better have that non- issued equipment and let this be an end to this kind of nonsense." happens, and not high enough that it never leaves the General's baggage car.
This creates the demand. The only way to get them, is for the force in question to order them, which the jealous higher ups will do. bs0-co military supply division is happy to supply paperwork with suitably "mission focused" designations for the devices. Suggestions include: "Ruggedized Comms Subassembly 241", "Cold weather crew survival generator kit (with bag)", "NBC calibration standard" etc.-- bs0u0155, Mar 06 2020 Atomic Battery [xaviergisz, Mar 06 2020] RTG palm [xaviergisz, Mar 06 2020] Long lasting radioactive battery https://www.indepen...china-b2476979.html [bs0u0155, Jan 22 2024] In principle I like it, but I must point out the obvious contamination risk that'd occur when a soldier inevitably opens it.-- sninctown, Mar 06 2020 Is there some kind of perfect military? Remember, broken cellphones can now be found in street gutters.
Possibly, when the new tinier chelation agents are around to be administered.-- wjt, Mar 06 2020 //What's the novelty here?//
Batteries were around for ages. Powerbank phone chargers came along later, and people went "aahhh, yeah, want one of those". So it's a combination of a power bank and an RTG. An iPod was just a small laptop hdd and an mp3 player+marketing. But this one has a coffee warming zone!
You could argue it's a "distributed core" weapon. You'd need ~350 of these and you can assemble a fissile core! It was hiding in plain sight.-- bs0u0155, Mar 06 2020 Now just make it a phone charger... <link>-- bs0u0155, Jan 22 2024 random, halfbakery