Solar Kit
Just received my kit. 2 100w panels with a 30a pwm controller. Hoping it will recharge my 2 GC2's. I am alone in the trailer and power use is min. Any thoughts?
Forum Discussion
red31 wrote:NinerBikes wrote:
So you are getting 14.9V at the battery on a 60w panel, at 3.1 amps?
Not really, during bulk the amp meter is steady but in PWM the meter is erratic.
https://drive.google.com/file/d/0B-r-cHocscVWUXJBb1NRVVNDd2s/view?usp=sharing
I have a 20 amp Charge controller like yours, with adjustable Voltage, and it exhibits the same low amps flow in it's PWM algorithm. It's like it throws half of the amps away 2/3 of the time, by dropping the charge voltage and amperage down, so it makes it a really slow charging Charge controller, that actually spends very little time in bulk charging voltage or amperage, despite the battery being able to take on more charge.
I ended up buying a Solar 30 charge controller, that has a much better charging algorithm built in... when your battery is low, it flows the Voltage and Amperage at much higher rates, 95% of the time, although it still PWM charges, it doesn't have the huge V and Amp drops that your model provides, as a "feature" which is not really too beneficial if you have partially cloudy days and you want your battery top charged.
For my purposes, the Solar 30 is a much more efficient charging unit than this device shown. I want an algorithm built in that flows high amps 90 to 95% of each second timed, the when the battery is below 95% SOC.
That unit will lead you to believe that you need to buy more solar panels to get more charging amps to your battery, when it's the charge controller that's really messing up with your charging efficiency from your existing solar panel set up.
Buy a RC watt meter, like this, that measures your cumulative amp hours, and do some logging, and you'll see how short this unit is on delivering the amp hours you need to charge your batteries.
RC battery charger amp hr /watt meter
