Sky Solar charger failed - again

I only used both solar panels because I didn’t want to throw it away like I did the first, Ideally I’d have 3 facing E, W and W so it saw the sun properly whatever time of day.

Yes it would be perfectly fine with one, provided as they say the panel is large enough to get to the charge start voltage in Cloudy UK weather conditions.

I realy did go overkill with the amount of batteries but it should run for at least 6 months I reckon without sun once the cells are fully charged

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I couldn’t find how you connected the battery door plate to the negative terminal. If you didn’t, then those batteries are merely spacers.

Also, soldering on the battery terminals very likely damaged the battery so don’t be surprised if you don’t have as much capacity as the label stated.

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cr@p I had to forget one thing! I meant to solder it to the negative terminal, I’ll do it when I can get someone to take it down again
and I’m not worried if they lost a little capacity, it’s highly unlikely it did as it was only applied for a moment and I have done it many times in the past, and the correct way of attaching a terminal applies a hell of a lot more heat than I applied, besides it’s still a hell of a lot more capacity than it had

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Other than the SPA mod you did, a much simpler way to mod a SKY would be to get a LiFePO4 cell slightly smaller in diameter than a 26650 so it fits or several smaller ones like you did and then just put an adapter between the cells and the other terminal in the battery cavity. No modification to the SKY would be required.

Proper spot welding of tabs on a cell doesn’t allow as much heat to make it into the cell as soldering does. The localized temperature is higher but the total amount of heat is not given the very brief time it is applied.

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So basically the same as I did but with 4 batteries instead of 8

The reason I didn’t use an adaptor the same size as an AA cell is I live upstairs in a small flat (apartment if you’re American) no workshop or anywhere locally to get one or make one up so I did the best I could do with the little resources I have and I’m happy with it.

Like I said I don’t have a workshop or tools and I had to make do with what I have

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I’m not discounting what you did or what you had to work with, only your claim that soldering put less heat into the cell, which is not true with a properly spot welded cell. It is one thing to solder NiCd cells and quite another to solder Li-ion type cells and didn’t want others to get the wrong idea.

If I had thought of your idea before I made my external battery mod I would have gone with your idea, without the mod to the SKY, since it doesn’t require an external battery. I may see what I can find for different LiFePO4 cells. If some were made which were the length of two AA cells and the same diameter it would make for an easy mod indeed.

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I know at this point this is a science project for you guys, but considering how many times he had to take the unit down, wouldn’t it have been far easier to just remove the solar completely and put some new AA batteries in there to enable the station to make it through the winter season ?

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The point of having a Solar battery is never having to put new ones in there.
Why have something if it doesn’t work properly.
THATS why I did it

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Really nice job thanks for the write up :slight_smile:
Your gold contacts appear in perfect condition. I have had issues with water ingress during gale force winds which then corrode the contacts. When I install a Sky in a difficult to access location I use contact grease on the contacts and flashing tape around the joins to the SPA. I have also used silica gel in the battery compartment and have also tried drilling drain holes in the SPA and the mount. An issue is that the Sky will be hot in the sun causing a high pressure air inside and then when a rain storm hits and cools the Sky the air inside cools and causes a vacuum which sucks what is now wet air or water if it can. So my silica gel option I tried for a water tight setup while without the silica gel I use the drain holes down through the mount attempting to allow the driest air to breath into the Sky, rather than breathing through the seal of the SPA which would be wet.
And I imagine removing the cover off the Sky may have damaged the seal below the ultrasonic sensors which might allow water in that was not entering previously. I did have a Sky with a cracked neck which allowed water into that area causing the nut and washer to corrode.
Good luck cheers Ian :slight_smile:

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This is why I wanted to fix my solar charging, I’ve been working on this for a long time but as I only know Basic and not Python or C+ or any of the better languages it’s taking a while to get right.
I know it’s not perfect and there are much better displays around but none were what i wanted so I made my own with a Raspberry Pi and mmbasic, and esp32 with annex wifi rds basic
19inch monitor on my wall

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good work. the dog is a nice touch :slight_smile:

it looks nice and functional. Nice work

17 posts were merged into an existing topic: Tempest Battery Not Charging; Need Power Booster