in my opinion, and as unpopular as my opinions might be... here it is.
you are looking for the holy grail of RE, the home built battery capable of being built out of junk laying about and capable of doing real work.
that is very close to perpetual motion in reality.
don't you suppose that in this day and age of the internet, and every DIY'er on the planet working away on wind machines, water turbines, soldering together stings of cheap solar cells, gasification, slowspeed diesels, steam and everything else short of a bucket size nuke reactor, that there would be someone that has built such a battery and has actually published the results on the net? and if there were one there would be a thousand such dudes all over the place replicating and improving on the process.
there is a reason that batteries are expensive, heavy, and toxic, and it isn't because of some secret technology, its all well known stuff for the most part over a century old... the reason everyone isn't doing it is the actual reality of building a useful battery is a difficult endeavor using accepted practice, let alone trying to do so with recycled scrap bits and pieces of varied quality.
in my opinion, forget reinventing the battery and skip directly to the generation of power.
the biggest bang for the buck is the car alternator, and building a gasifier to fuel a small engine is relatively easy to do (much easier than building a battery from clay pots and scrap materials). you can certainly find a car alternator capable of a kilowatt, a small engine to power it with, and provide a buffer battery (from a used car, it doesn't have to be a very good battery) and attach an inverter. building and fueling a gasifier to fuel an engine that does not have to run at a specific speed makes it much more doable too.
yes such a system could be stolen, but my bet is the village could secure this small amount of equipment easily, especially if it made useful power for them.
far easier to located sticks and twigs, buffalo dung, or other scraps to gasify than it would ever be to get a kid to peddle a bike generator. an arm full of sticks would make more power in such a system than a kid could muster pedaling in a week in my opinion.
if you were a kid and were asked to do one of the following which would you do?
1. gather an arm load of sticks or buffalo chips, or
2. climb up on this bike and pedal your ass off for even an hour
(again, an arm load of sticks will produce more power than he, me or you could do in a week pedaling a bike)
just avail yourself of the net, look into how folks make power living offgrid, look at how they started out when funds were either low or non existent. (who cares how the rich guys do it anyway) the net is full of small engine driven alternator plans and idea's.
if you can't source those parts in SA, then the villagers really have no need for TV anyway. if there is so little available to them now, having a TV will only piss them off and make them depressed.
sometimes ignorance truly is bliss,
(ignorance is not a bad thing, sometimes knowledge is much worse)
point being you might consider the law of unintended consequence, you might think you are doing a noble thing and later find out it makes life much more difficult for those you are trying to help.
probably already said more than i should have,
again not intending to piss off anyone, just another viewpoint that's all.