The first battery-powered test was successful, in the sense that the board was working. However, I was surprised to see that the GPS was unable to get a fix after 5 minutes. I put a battery into the GPS only recently ,so I guess it has to download the ephemerides. But I’m surprised anyway, because I thought a “cold start” was around 30s. I’ll have to do more testing, the point being that I have to do all this outside, because the GPS and satellite modems don’t see satellites when I’m in my ground-floor-on-a-two-stories-house workshop, with Argon-insulated windows that attenuate the signal even more. And taking all my equipments outside is a bit of work.