Hey guys I am looking to get a solar charging unit to mount to a jon boat for fishing, Now knowing that wattage=volts * Amps, I am trying to figure out how well a 5 watt charging unit will do charging the 12v batter that operates my trolling motor.....Cant seem to find any similar units that show what the charge rate would be (time/power it will charge) anyone have any expertise?

we did this with my bass boat. we used the car solar charger that plugs in the cig lighter. it gave us like a extra hour after sitting in the sun while we were fishing

id recommend it plus u can use it to charge your cell phone and such

we did this with my bass boat. we used the car solar charger that plugs in the cig lighter. it gave us like a extra hour after sitting in the sun while we were fishing

id recommend it plus u can use it to charge your cell phone and such

yeah thats what im thinking.... harbor freight has a 5 watt unit for like 37 dollars figure its worth not worrying about the batteries on electric only waters.

I spent my career designing electronic circuits, but my knowledge of solar collectors is limited, so take this for what it is worth.

If the unit you are looking at is rated like a lot of other electronic gadgets, it is capable of providing 5 watts of power under ideal circumstances.  That equates to a bit less than 1/2 amp at 12 volts when the sun is bright and the collector is oriented exactly right.  There are probably some other losses, so I would suspect that 1/3 amp to charge a 12 volt battery might be reasonable to expect.  You could probably expect the battery to deliver about 1 amp for an hour after three hours of charging.  That might be reasonable for a small jon boat.  It certainly should help reduce the amount of paddling needed after a long day of fishing.

According to the Minn Kota web site http://www.minnkotamotors.com/products/battery_chargers/select-a-charger/?linkidentifier=id&itemid=2890 their 6 amp charger takes 10 to 12 hours to bring a single battery back from a 60% discharge. Their 10 ampper requires 4 to 6 hours. Your 5/12 amp charger, under ideal conditions should take about forever