Solar powered power brick

[bushtech]

Got this brick fairly recently. Noticed on overlanding trip that brick was not charging via sunlight. Charge it from my cellphone charger and charges up fine. But I can leave it sitting in the sun for days and state of charge does not change. Can be seen by 4 blue LED's that light up when fully charged. Fully charged state seems to be 4.2V. Putting the charger in the sun and measuring voltage between S+ and S- I get 4.2V from the solar panel, but it doesn't reach the battery it seems.





Please can somebody suggest what/ where I can check to get to the bottom of this.

Thanks

 

[Bluejets]

4.2 from panel probably not enough. Do you have details on it as we do not.

 

[bushtech]

Oops, sorry, blonde moment. Red-E brick
http://www.red-electronic.com/products/powerbanks/red-e-solar-powerbank-rs80-detail

And thanks Bluejets, you're right, Input 5.1V

 

[debe]

200Ma solar panel will take forever to charge that battery.

 

[bushtech]

Hmmmm. I'm going to unsolder one lead from solar panel and stick an ammeter in there and see what it gives. Thanks for the heads up @debe

 

[bushtech]

Overcast day here. Stuck my DMM in the line from solar panel to pcb. Getting 5V but only 8mA.

Rubbish solar panel?

 

[debe]

Over cast day is not realy a good test as the output will be severly reduced. The biggest problem is the manufacturer has tried to fit a solar panel to too small an object. You realy need a phisicly larger panel to do the job.

 

[bushtech]

I haven't been able to find a similiarly sized panel with a higher charging rate so might go for something like this which should kick butt.

https://www.banggood.com/Universial...-Tablet-Cellphone-p-1139819.html?rmmds=search

 

[bushtech]

Ugh! Sun out now. Even pointing the solar panel aligned at the sun I only get 50mA.

Looks like I bought a pig in a poke

 

[debe]

The Banggood one should be mutch better at 1A output.