Last edited by Captainleeward; 06-13-2018 at 06:54 PM.
garage nut hello, I bought a 12 volt car battery solar panel puts out 2.0 watts and shuts off when battery is charged.
last night the light went off at 3 in the morning so I'm thinking I have a problem of discharging this battery to much.
Anybuddy got any solutions?
one solar panel charges the generator stater battery and the other is charging the security light.
Last edited by Captainleeward; 06-13-2018 at 08:05 AM.
Cap'n, The 2 watt panel is rated max charging at full sun, beyond that it drops off significantly with time of day...etc. Basically the panel may only typically deliver ~1A or less (and who knows what the voltage might be) depending on the state of the battery and regulator on the panel.
The 3ah battery will take probably six hours+ to charge from a low to mid charge level and to finish topping it off may take another 3. New bike batteries will have a bit a of lag in time before they can deliver the full 3ah in my experience...usually 3 charges. They are typically charged on the bike at about 13-14V and the regulator reduces voltage and current as it gets close to top off. At 10W @12V you are pulling approximately .833amps per hour of on time. So from a fully charged 3ah lead acid you might get 4-6 hours of run time before the Cree kicks out from low voltage and drains the battery.
Seems odd that the photo cell kept it on till 3am...might try moving it to a better location or pointing it differently.
Personally I might try adding another panel in parallel or get a 5w panel, but you must keep in mind if this is a daily light show that battery won't last long because its not a deep cycle.
At's all I can suggest....good luck.
Try an App called "Solar Tilt" on Android.
It picks up your position and then calculate for that time of the year at what angle your panel must be for maximum efficiency.
Then it also has a spirit level to assist in getting it spot on. It makes a huge difference.
I have made my panel to swivel and the stay at the back now has 3 positions.
One for summer, one for winter and one for Spring/Fall
Here where I stay it varies from 7 Deg from horizontal to 54 Deg from horizontal. You can even calculate that Spring/Fall will be at 31 Deg.
Yep there is an app for everything these days my phone is full of them and have never figured out why or what use any of them are my phone is part of a group plan and every time my friend's wife adds some silly new app to hers my phone explodes. I spend half my time having to block or delete stupid apps from my phone.
I don't have much input for the micro solar stuff but it would seem to me that a 2 w panel wouldn't do much more than almost cover the parasitic load on a battery if that much when connected to a vehicle.
a 2 w panel with 10 hours of full sun would only be able to yield 0.4 amp hours per day.
You need to know the wattage or amperage draw of the security light x total hours of use to determine the size of the battery and the solar panel to keep it charged
Also does the panel have a blocking diode built in to keep the panel from drawing power from the battery at night?
My system when I had it set up to power my RV was an 1100 watt array feeding a 60 amp charge controller to charge a 1200 AH 12v bank the inverter was a Dimensions 1800w pure sine with a 3900w 45 second overload this was sufficient to power the TV a 23 Cf fridge 1000 w microwave/ convection oven the coffee pot and the toaster and lights it would only kick out when trying to use oven toaster and coffee pot at the same time with judicial usage I only had to run the main generator occasionally
Post your reply!
Join 42,532 of us and get 500+ tool plans, tool eBooks, build guides, and much more.
Never try to tell me it can't be done
When I have to paint I use http://kbs.justoldtrucks.com/
There are currently 1 users browsing this thread. (0 members and 1 guests)