I put a bigger battery in the laptop station and reconfigured the wiring in the control panel to accept additional panels or batteries…I also now have the charge controller hooked up. I was a little concerned about the high charge voltages without it. I also put together a little video about it. You can watch it on youtube.
Sweetness!
But as a heads up, the “open voltage” of a panel is generally very high compared to the charging voltage. For example, my 3 15 watt panels (in parallel) have a open voltage of about 18V, but plug them into a battery and I only measure a voltage of about .2-.4 volts over the battery itself.
Since my input and output of my system is very small, it generally hovering around 12.6-13.0.
Is this similar to what your are seeing? I also am using a wet cell deep cycle battery which vents, so no issue really with over charging, which I know is a much bigger issue with your sealed cells.
Yes, I have seen open voltage as high as 20.8 on this panel. These SLA’s have a target charge voltage of 13.6 to 13.8 for standby use and 14.5 to 14.9 for cyclic use. The sunguard charge controller output PWM is 14.1 Which is idea for these batteries, in my mixed standby and cyclic use…they can’t take over charge since they are sealed. The 17 volts shown in the video was on an overcast day…bright clouds, when its a blue sky day its over 20 volts.
I hope to get started on the “bigger” solar generators this afternoon…Same panel + Charge controller but with two 12ah 6 volts in series…with a dual cigarette outlet…one for whatever and one dedicated to a 300 Watt Modified Sine Wave Inverter. All of that in a slightly larger box. My goal here is to have something that I can run the DSL modem from if we lose power…which still happens a bit.
Then one recommendation, most DSL modems, wireless routers and other such light duty home networking equipment generally uses less than 5 watts, and may spike at up to 15. Save yourself a lot of power wastage, and take the wall wart power supplies these things come with to Radio Shack. They will have a generic automotive power adapter you can use and avoid the double power conversions.
From 12 volt to 120 then back to 5.1V…good call Grant I will have to grab one.
Good points!
great!!!!!!