tonyt74 wrote on May 20
th, 2011 at 3:37pm:
Can you use it to run a fishfinder, and use the battery pack as a backup power source?
Looks Sweet, whats the price tag though?
Well, its not so much a matter of volts as amps. The solar panel mentoned above is rated at 15 volts, but only 300 milliamps. So the weak link to power a fishfinder directly is the amp output ... and 300 milliamps (.3 amps) is insufficient to power most electrical devices directly. To illustrate, the manual for the Cuda 300 fishfinder indicates that you should place a 3 amp fuse in the DC power line. This translates to an operating power draw of less than that. So, I'm guessing that a typical draw would be on the order of 2 amps. Consequently, the solar panel produces on the order of 15% of the power needed (.3/2).
Consequently, it will be necessary to use this solar panel to recharge batteries. (In this context, the solar panel operates as a trickle charger, producing a maximum of .3 amps per hour.) I run my Cuda on an 8 AA pack. The individual batteries are on the order of 1.5 volts and something above 2000 milliamps. So the 8-pack produces 12 volts and 16 amps. This configuration should produce about 8 hours of continuous use. (But since I'm currently using lithium batteries ... 3000 amps, this is more like 24 amps or 12 hours of continuous use).
Of course, these numbers are only approximate and depend on a lot of additional factors (e.g., temperature, battery efficiency, etc.)
As indicated in the original post, I paid $57.77 for the panel I purchased. It is possible that you could find it cheaper.
dd