elvatoli wrote:It is possible that my 5 W harbor freight panel is actually draining my battery instead of charging a little bit ?
Yesterday I took a measure during daulight of the panel terminals with my voltmeter and the reading was -.015.
Ideas ?
thank you
Hector
RGV, TX
I can't comment on the HF model, but I had a cheapo 1.5w deal that when I came back after a week had drained my battery.
Try putting your tester on ammeter and connect it to the solar terminals and see what it's putting out.
I use an inexpensive Harbor Freight 6W solar panel and it charges 2 batteries on the boat without issue. What you are likely experiencing is the panel discharging the batteries overnight or on cloudy days. WIthout sunlight, the panel can present a load on the batteries drawing some power from them which is then expelled as heat. The fix for this is to put a diode inline between the panel and the batteries so that current cannot flow into the panel, only into the batteries. Less expensive solar panels do not have a diode. I added one myself to my HF solar panel and it works fine.
When you installed the diode for your HF solar collector did you install it on the positive or negative line? Also is there a direction the diode must face? I lookede up a diode that is for solar collectors and it is an ATM type fuse and holder, that is why I am asking.
Haven't been following this thread as it's been discussed many times prior but with regards to the voltmeter test on the terminals, if there is an unobstructed view of the sun without shadow you should get a voltage but without a load this may not happen as one of my 65w will only give a brief reading and then go back almost to zero on a multimeter.
The diodes can be installed in either or both leads but must be the correct way round.
Depending on the type of battery 1.5 amps may not be enough but then could? be too much with others, I would be worried hooking up a solar panel to a battery without a regulator as they can put out 22v.
I put the diode on the positive lead and installation direction is important. WIth the output of the little 6W panel under load, voltage is not too high for the batteries. For a larger panel, I would agree that some type of regulator would be necessary.
