I'm seeing all these parts as components of one assembly, perhaps after being burned. The cylindrical things with bolts on look like rollers from a drive chain. The flat parts might have been attached between the rollers.

I think this is the remains of a broken track from a small tracked estate vehicle (Haflinger kind of thing), or maybe a snowmobile belt, or maybe from a tree-logging machine. The rollers would have been joined by rubber webs and the plastic feet encased rubber extensions to stop them wearing off too fast. The rubber composite has either been charred away or weathered - maybe it was designed to be biodegradable.

Those things look to me like pretty straightforward cells from a largish battery, possibly a zinc-carbon cell of some type. Paul seems to me to be right about the rest of the equipment.

As for what they were doing where they were, I cannot of course be specific, but in general the infiltrative capacities of the human litterbug are amazing. Whether forester or tripper, whether cutting, travelling or touring, someone passed by on some personal errend inscrutable, found that his battery had failed or his bearings had burned out, so who cares about whether we leave them here? In fairness, it might have been an emergency, with a life at stake, so never mind a kilo of litter, we must get Fred out of here while there still is a chance to save him.

All very speculative.

Except that I am pretty confident about those electric cells.

Cheers,

Jon

I blew up the photo images but at that resolution, one man's pixel is another man's portal. I can see a black electrical lead with an exposed tail, totally uncorroded, which might be evidence for an electrical device or be totally unconnected (in both senses). Also, I would love to see the remainder of the flattish triangular plate at left - maybe part of a loudspeaker mounting?

Next time I go up a mountain, I shall take a ruler for putting in photos to get a scale, some callipers, and a spring balance, and quite possibly a spectroscope. Hey, maybe its a portable ...

Reason I think not batteries is: I believe I can see flats on the end bit of the one nearest centre, and it is still largely bright. From comparing the scale of fingertips and the other parts in the other photo, I would identify the grey bit as the head of a 10mm bright steel bolt. The one at the bottom even seems to have the business end of a bolt peeking out on the right.

Why has it got obvious copper salts on the lower edge of the "bolt head"? I think the adjacent part is a big flat phosphor-bronze washer that used to retain something that swivelled behind it, causing electrolytic corrosion. It seems a bit thick for a battery casing, and it isn't the normal pitch or plastic insulator used at the top of batteries.

The darkness of the main body is wrong too. Batteries are normally sheathed in Zinc or Alu and they corrode into a light/mid tan (although Cairngorm might be a subtly different environment to inside a Walkman). It just looks like old iron, thick and pitted (somewhat like myself) - in fact some of the pits are deep enough to penetrate a normal battery casing.

Mind you, I can't account for the white irregular blobs - they look just like the mushy electrolyte inside a dry battery for some reason.

No other solution, Jon: meet me at Aviemore Station 11:00 Saturday, and we will go and find the site and figure it out over a beer. Stay well!

Gosh, did no one take a battery apart when they were young? These are carbon plates from a large square radio battery that used to be quite common years ago. The rolly ones are from cylindrical zinc carbon batteries, the zink case having probably coroded away. 

The flat plates look like the internal parts of a PP9 zinc carbon battery. 6 carbon 'biscuits are encased in a thin plastic shrink wrap . The rods are probably from a 6 volt lantern battery as used for 'skip' lights. These batteries contain 4 rods usually encased in a zinc cover and sealed with a bitumen top. I imagine these batteries could power weather baloon telemetry but this is just a guess.