Tuesday, May 27, 2008

Found the limit

I've found the limit of what my solar power setup can handle, and did my first deep-cycle of the batteries.

I was very much an Interet hermit this weekend, and spent three solid days curled up inside the van, on the computer almost the whole time. I didn't leave the van except to go to the bathroom and buy some food. But I was also parked in a relatively shady spot, with the sun obscured by a tall building most of the morning and by trees all day except for a few hours in the afternoon. And winter has arrived in San Francisco: our cold season is now, when it's foggy and windy all day every day. So not much sun.

With the computer running all day and night, and not enough sun to really fully charge the batteries in the day time, the batteries got down to 12.1 volts for the first time ever. The yellow warning light came on to the charge controller.

Today I'm in full sun, trying to recover from this error. The solar panels are pulling 11 amps, and the battery is STILL not charged at 11AM, and the yellow warning light is still on.

I'm going to get off of the computer now and let the batteries charge up all afternoon, in the hope that by late afternoon they'll be back up to their customary happy 14.1 volts, and the charge controller will be buzzing like an angry bee, which is what it does when the batteries are full up and there's tons of sunlight streaming onto the panels.

I hope it will, anyway. It'll be an interesting experiment.

Sorry, batteries. Didn't mean to pound on you so hard.

UPDATE: Well after a full day of 11 amps, the batteries STILL did not fully charge! I shut everything down, and now after a foggy morning at about 6 amps, and an afternoon that's starting to clear and a few hours of 11 amps, I'm finally seeing 13.8V and the controller is finally starting to buzz and whine as it does when the batteries are nearing full charge. Still no 14.1 volts yet, though, and that's full charge. I hope to get there within a few hours.

UPDATE 2: It took THREE days. It is May 29, and, after sitting it in full 11-amp sun, and not using anything electrical all morning long, by early afternoon the thing was FINALLY up to 14.1 volts. Very happy that it got there. Tonight when the sun went down the batteries were at 13.1 volts, which is the normal "start point" for the evening for me. Usually after many hours of nighttime computer use, by the time I go to sleep the batts are at 12.7 volts.

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