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geno-heidi · 12-02-2012, 04:44 PM

Hi....Thanx for the previous solar help...here's my new set up quest: A) My small 20 watt panel...meter shows 19volts in full sun (rated 18v)...up on RV roof, connections 18.6-19v, then I clip to battery (using alligator clips for temp before solar-controller comes in), and meter measure on clips--attached to V10 Battery--shows only 13.4-13.6v...??? How and why is this ???

B) I am running direct to 12v V10 Battery 'without solar controller' for now, few days to see how its working...will this possibly harm my 1 yr old Interstate V10 batt.??? As above, putting out 18-19v at panel wires, @ 13.4-6v on Battery Terminals...??

C) There does not appear to be any kind of 'diode' on this panel (20watt, 18v output, 1.11amp), only junction box with 'correct' +/- connectors in small junction panel on back. I hear references to this issue regarding 'night time battery drain from solar panel' if not equiped with a diode. What will be "draining" on the battery from a solar panel hooked up and no sunlight, in the dark?

Thanks AGAIN !! Just getting 'Solar Started'...

jofo777 · 12-02-2012, 05:16 PM

The battery is naturally creating a large resistance and knocking the voltage down. That voltage at the battery is actually pretty good and nothing to be concerned about. As for harming the single battery, as long as the voltages are below 14.8, all is good and that will be a full or nearly full charge. Be sure and measure at the battery to get the best results. Don't let it go over 15 volts or it will boil the battery water out. Once a month or so, you can equalize to 15.6 to desulphate the plates and ensure a long life for the battery. Read up on doing it properly and disconnect the house circuits when you do it to protect the electronics you have.

jofo777 · 12-02-2012, 05:18 PM

Without a diode there will be a small drain on the batteries when dark. That's why they use diodes. The solar controller will eliminate the drain as well.

vsheetz · 12-02-2012, 06:38 PM

A diode is a one-way valve for electricity - in this case a diode would allow electric current to flow from the solar panel to the battery, but not the other way around.

Like a tire valve stem core allows air in but not back out.

geno-heidi · 12-02-2012, 06:58 PM

Quote:

Originally Posted by jofo777

Without a diode there will be a small drain on the batteries when dark. That's why they use diodes. The solar controller will eliminate the drain as well.

Hi, Thanx!! If it's a 'solar panel' and dark, and it's night, what is creating the drain?? Just because it's hooked upped to pos/neg?? And...would that same 'drain' negate the gains during the solar-daylight hours??

Only a 20 watt panel...1.1amp...18vDC max

Thanx again...!!