I'm sure the open circuit voltage will excede 17 or more volts. This is no problem as the panel is a low output panel, and when hooked to a battery
, it will noy overcharge the batteries. I have used a 85 watt panel and 2- 15 watt panels
to charge 2-6 volt colf cart batteries, without a charge controller. No problem. And this is continous use.
Can't remember where, but I read a while ago that if you panels
are below a certain percentage of the battery
bank, a controller is not needed.
Also I found that by not using diodes to prevent discharge at nite, you come out ahead, as the diodes cut the charging voltage by about .6 volts. That .6 volts makes up for the slight discharge at nite.
Getting the boat back in shape for more cruising, this time we will be using 200 watts of panels, and have a controller for them.
As a note, with the solar panels
, or a wind
gen, be sure not to shut off you battery switch, if the charger
is not hooked up to the battery side of the switch. Mucho voltage, when not regulated by battery voltage = bye bye electronics!
When I first hooked up a used wind generator
to test it, we hung it over the fore deck
, an plugged it into a cabin
light socket. The voltmeter showed it was charging.
picked up and I decided to turn it out of the wind to stop it and tie the blade off. I turned it 180 degrees from the wind, and it kept turning! We figured the battery was motoring the generator
. (A wind gen. is just a mtor) So we turned off the cabin
light circuit switch. MISTAKE! The cabin lights turned into super novas!
Without the battery in the circuit the voltage was over 18 volts. We didn't have the generator
turn out of the wind when we did it.
A diode in the circuit was what it needed. Lesson learned.