Celestron Evolution with a Power Tank

[BlueAstra]

Had a strange power supply event last night. I haven't used the Evolution for a few weeks, and I think I charged it up fully after the last time I used it. Last night I had it out for a session. It has a Celestron gps unit, HC, attached and the tray lights are on. The weather was mild, about 9C, but humid. I controlled it from an iPad using Sky Safari Pro. It ran for about two hours and then both power and wifi lights went out and I couldn't connect with the iPad. I assumed the battery had discharged.

Once inside I examined the power status. With the power switch ON the HC said '9.9V discharging', with both lights off. I could still move the scope with the HC buttons.

If I connect the mains charger (output 12.09V), power switch ON, the HC says '10.42V charging'. The power light flashes quickly and the wifi light gives a slow pulse. If I turn the power switch off the power light is off and the wifi light pulses slowly.

I also have a Celestron Lithium power tank (the small cylindrical one). This reads 13V when switched on. If I connect it to the Evolution, with the power switch OFF the wifi light pulses quickly and the power light also flashes quickly with a synchronous audible 'click' from the electronics. If I turn the power switch ON the wifi light pulses slower and the power light still flashes quickly, but with no 'click'. Also, the HC still says '9.76V discharging'. If I turn the power tank off the HC still says '9.76V discharging'.

I never checked the voltage before the session, so I cannot be sure the Evolution was fully charged, but I wouldn't have expected the battery to discharge so much in a few weeks of no use. I also have no idea what's going on with the power tank. Its as if its doing nothing, maybe because the voltage is too high. Its behaviour is certainly different to the mains charger.

Any comments about what's going on would be welcome. Is the Evolution battery OK? Should the power tank work? What do all the flashing lights and 'clicks' mean?

Graham

[mraa925]

Check the socket on the Evolution to make sure the center pin "split" has  not collapsed on you, thus not making contact with neither the charger or the power tank.