I went out today and did three rings, The first one was about 30, the second about 20 and the third another 30. I started at 10am and finished at 9pm, it was dark by then, but I had my head torch.
The first ring was "Pilton and back", and that went well, apart from one that took a long time. I got back to the car, had a coffee and a sandwich, relocated the car, then went out to do "Apethorpe Archive. I've already done three of those a while back. The highlight of that series was "Sneaky - the box II". I was just getting ready to give up, when I spotted an interenting place to hide a cache, and sure enough, there it was!
I started the third ring at 5pm, so it was always likely that I'd finish in the dark; I took a headtorch and extra batteries. This was "Tansor and back", and it kept reminding me of tensors, which I never did really understand. They're like vectors, only more so.
That ring was made extra-interesting because my bike failed after the first few caches. Careful examination revealed that the wire going from the batteries into the controller had broken, so no power was getting to the bike.
An electric bike with no electricity is still a bike, so I pedalled to the next two caches, but by the time I'd done them, I'd formulated a plan. I used my pen knife to strip the broken wires back a centimeter or two, then twisted them together, and I covered that with insulating tape that I carry. I arranged things so that there wouldn't be any tension on that wire, and, to my considerable surprise, the field repair A) worked and B) lasted for the next few hours.
Doing this, of course, meant that it was quite dark by the time I got back to the car, but it's only dark if you don't have a torch. Or if the torch that you do have, hasn't been used for several months and the self-discharge of the batteries means that the light is a bit dim.
76 caches done, no DNFs.