A customer brought this amusing little item to me on Christmas Eve. He
needed it fixed that day but it just wouldn't have been possible, so he took
it back to try and get a refund. I'm posting this message just to satisfy my
curiousity.....
The toy was a remote-controlled flying saucer. The saucer was a
lightweight styrofoam rig with the electronics crammed into a small space at
the top. Upon engaging the remote, a propeller would start (accompanied by
blue and red LED's) and the entire unit would spin rapidly and climb to the
ceiling. Altitude could be controlled by how much pressure was applied to
the remote control trigger.
At least that's what it did the night he got it home. He had to try it for
himself before wrapping it for his grandson, and after marveling at the
device he plugged in the charger and went to bed. When he tried it the next
morning, the device would run but didn't have enough power to lift off the
floor, even though the batteries should have been fully charged.
The battery pack was a very small NIMH type consisting of five cells. It
had the specs 6.3V, 150mAh printed on it. Pretty small considering the
load - I hooked up a decent 6.3V gel-cell and measured about 2.2 amps power
consumption! Not surprisingly, with a decent power supply attached, the unit
worked fine. When the original battery was used, it's voltage would drop to
about 5.7V under the load. I tried hooking the battery to a small lamp (6V,
500mA) and the voltage still dropped to 5.7 volts. The instructions say the
battery takes 20 minutes to charge - at this point I suspected the battery
had been overcharged and ruined, and since I couldn't possibly obtain such a
specialized part on the same day, the project was aborted.
My question is, how much load should such a small battery pack provide,
without a significant voltage drop and assuming it is not damaged? Do you
think my diagnosis was correct?