Electronics > Power/Renewable Energy/EV's

My First Solar Panel

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metrologist:
I bought a 100W solar panel off ebay (http://www.newpowa.com/v/vspfiles/downloadables/NPA/NPA100-12.pdf). I then bought an Anself CMTD solar controller based on a video I watched before the one below.

I'm not sure what I'm going to use this for, it was just an impulse after experiencing a camping trip with friends who had the 45W Harbor Freight solar kit. I thought this would be a better setup and hoped to use LiION cells. I might take an appliance - like a TV or computer - or maybe just a few room lights off the house circuit and put it on this solar system. We pay about $0.2/kWH.

The video explains that the charge cycle and voltage cutoff seem good for a 12V LiION system, except the controller goes into trickle charge with around 70mA. I was wondering if I just put a switched load of that amount on there it would more or less solve the issue (or a TV might even have that much standby load), or is it not that much of a concern?

metrologist:
Too cheap?

Next, I have a lightly used Subaru alternator and one of those 48" shop fans that is destined to become a...windmill?

metrologist:
The solar panel arrived today. I ran it outside at 7pm pointed at the sun with a DMM and was getting 22.4v and 2.94A direct from the panel. Inside in subdued lighting it was 10v and 100ma.

metrologist:
This solar charge controller is disappointing because it seems they could just open up the settings and have a more useful product.

I mean, it seems to work as designed, but this particular model, the Li-ion version, has locked all of the settings except a timer, which I have no idea what use is a timer? What would I be setting?

The other versions of this controller let you set the PV and load on and cut-off voltage, and the battery type. The Li-ion version is fixed at lower values, and that sucks!

It may also have a problem because I've not been able to get current from the PV above a trickle, even when there is a 400ma load. One qualifier is that I am using a sealed lead acid battery until my Li-ion packs come in, so maybe the controller is doing what it should? I think that if the battery voltage is 12.6V that the PV is shut off no matter what the load is drawing. I need to play with it more to understand that.

Edit: I played with it more and hooked up a 3s RC li-ion battery pack. There wasn't enough sun to get a reading because the current reading for the PV is 400 ma lower than reality, so it was showing 0.0A.  :box:

metrologist:
I haven't been able to figure anything out.

I found an 11.1 V li-ion laptop battery that its own self test indicator shows 50% charge. It's been sitting for at least a year, but has more than 10V open circuit.

When the load is off, my DMM shows ~0.1 to 0.2 ma into the battery. Why would't there be more current into the battery to fully charge it? Maybe the battery is bad and wont take current?

The controller shows voltage jumping from 10.5 to 12.6V, and a battery bar indicator shows full with the last bar toggling on/off. That seems weird.

I turn on a 400 ma load and my DMM now says there is ~200 ma discharge from the battery; the controller voltage is jumping more rapidly in the range of 10V to 12.6, and the battery bar indicator is also jumping from max to min or in between... The controller also occasionally indicates some current from the PV, it can flash over an amp (1.2).

I'm confused.  :--

The PV alone measures about 22V open circuit and 5.8 amps short circuit. I'm happy as that seems like well over 100W, which is the panel's rating. I like that panel. :-+

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