Author Topic: Battery performance in the cold - D5300/D5500, D7500, D500 - test challenge  (Read 1699 times)

Řivind Třien

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  • Fairbanks, Alaska
Another update: During the above test and tracking attempt a few nights later where temperature dropped to -30°C, while the battery bank and camera worked without a hitch, my SkyTracker stopped working abruptly. First night this happened about half way, and the remote release cable appeared to be snagged between the rotating platform and the tracker, but the next colder night it only lasted for about 40 minutes before it stopped. I recalled some previous problems when it got that cold.

I then got the idea to also power the tracker from the same 9V outlet via the super-capacitor, and a quick test revealed that power consumption of the tracker is very low, only 70mA drawn from the battery bank. Last night the cold weather at -34°C appeared to open up enough with stars visible for a tracking test test closer to midnight. Of course right after everything was set up and aligned clouds started drifting in and with that it warmed up towards -30°C during the test. Clouds were still transparent enough to see some stars to check if tracking worked. Except that the camera hit the polar scope at some point (ouch, luckily I caught it after only two non-tracked frames so no damage done), the SkyTracker and the D7100 worked OK though the 4hour test. So as long as the tracker has power it might still work at these low temperatures. I will now incorporate the extra power outlet for the tracker in the final design. It is anyway very awkward to change the AA batteries on the tracker (needs pliers/leatherman tool to get the battery holder out), so using the 9-12V power inlet might be a good solution in spite of the extra cable clutter.
Řivind Třien

Seapy

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Very interesting Řivind, I am following this with great interest.
Robert C. P.
South Cumbria, UK