- 11,326
- 8,750
If you look at these curves from #39 again, you can see that dropping the panel volts from 19 to 12 means that it is pulling nearly short circuit current. (The difference between rated current and short circuit current is small. You can see that on the nameplate sticker on your panel.)
That raises two questions.
I repeat my earlier recommendation, Nicad or Lithium batteries are better suited to your application.
That raises two questions.
- If the panel is sending 1.2 amps, and the voltage drop is 0.23 volts, then the resistance of the connection is 0.19 ohms. That's too much resistance. Either there is a bad connection or an inadequate wire. 0.19 ohms is the resistance of about 12 feet of 22 gauge wire. 22 is far too small a gauge. 18 gauge wire gives about 1/3 as many ohms per foot. 16 gauge wire 1/4 as much.
- If more than one amp is going to the battery and the battery voltage is still less than 12, the battery is definitely bad (probably a cracked lead plate). Don't you have any current measurements? If you buy a replacement, make sure it is deep discharge battery. Also make sure all the wires in your project up to the Luxdrive are also at least 18 or 16 gauge, and make them only as long as necessary.
I repeat my earlier recommendation, Nicad or Lithium batteries are better suited to your application.