How to get most from this tiny solar cell?

Thread Starter

Singed

Joined Mar 21, 2024
1
Found this:

https://waf-e.dubudisk.com/anysolar...k/www/Gen2/KXOB25-12X1F DATA SHEET 202007.pdf

https://waf-e.dubudisk.com/anysolar...k/www/Gen2/KXOB25-04X3F DATA SHEET 202007.pdf

https://waf-e.dubudisk.com/anysolar...k/www/Gen2/KXOB25-01X8F DATA SHEET 202007.pdf

Same size with different cell configurations.

As title, how I can get the most from this cells?

I'd like to use one, or two if necessary (price is not low), for a small outdoor project. Didn't found a lot on this kind of cells. I suppose that efficiency is a goal to get something.

I've a small MCU powered by a 100mA lipo (with BMS), a 3.3LDO and a small battery charger, approx. 1mAh drawing.

What's more efficient; use this solar chips to recharge battery? Or should I use battery as auxiliary power and get power from this chip?

Connection advises are welcome (by switching, charge p
ump or.. idk).
 

MrAl

Joined Jun 17, 2014
11,581
Found this:

https://waf-e.dubudisk.com/anysolar.dubuplus.com/techsupport@anysolar.biz/O18Adzn/DubuDisk/www/Gen2/KXOB25-12X1F DATA SHEET 202007.pdf

https://waf-e.dubudisk.com/anysolar.dubuplus.com/techsupport@anysolar.biz/O18Adzm/DubuDisk/www/Gen2/KXOB25-04X3F DATA SHEET 202007.pdf

https://waf-e.dubudisk.com/anysolar.dubuplus.com/techsupport@anysolar.biz/O18Adzl/DubuDisk/www/Gen2/KXOB25-01X8F DATA SHEET 202007.pdf

Same size with different cell configurations.

As title, how I can get the most from this cells?

I'd like to use one, or two if necessary (price is not low), for a small outdoor project. Didn't found a lot on this kind of cells. I suppose that efficiency is a goal to get something.

I've a small MCU powered by a 100mA lipo (with BMS), a 3.3LDO and a small battery charger, approx. 1mAh drawing.

What's more efficient; use this solar chips to recharge battery? Or should I use battery as auxiliary power and get power from this chip?

Connection advises are welcome (by switching, charge p
ump or.. idk).
Hi,

To get the maximum power from a solar cell a max power point tracker is used, but you may not need that. You can charge batteries directly, but you have to have enough cells in series so that you get an open circuit voltage greater than the battery by maybe 25 percent or more. To charge a 12v car battery with charging voltage near 14 volts I used a 21 volt solar panel, for example.
 

Jerry-Hat-Trick

Joined Aug 31, 2022
583
Taking a quick look, it seems like you'll need your third link option to have an open circuit voltage larger than the battery voltage as a boost converter to boost the lower voltages would just waste power. When there is sufficient sunlight - and solar panel specifications are always optimistic - a lot of the time, you may only get enough current to trickle charge the battery and since you have a processor on board you can control the current so as not to exceed the battery specification, just dumping excess power, and turn charging off periodically for a brief check of the battery volt. MPPT (Maximum Power Point Tracking) may be able to optimise you charge current but I'd suggest keeping it simple if that will keep the battery topped up sufficiently to see you through the night, and days when it's seriously cloudy.
 

BobTPH

Joined Jun 5, 2013
9,174
What's more efficient; use this solar chips to recharge battery? Or should I use battery as auxiliary power and get power from this chip?
You need 3.3V x 1mA = 3.3 mW. The panel produces more than that. So, if you are not charging a battery, you are wasting most of the energy the panel produces.
 

MrAl

Joined Jun 17, 2014
11,581
Found this:

https://waf-e.dubudisk.com/anysolar.dubuplus.com/techsupport@anysolar.biz/O18Adzn/DubuDisk/www/Gen2/KXOB25-12X1F DATA SHEET 202007.pdf

https://waf-e.dubudisk.com/anysolar.dubuplus.com/techsupport@anysolar.biz/O18Adzm/DubuDisk/www/Gen2/KXOB25-04X3F DATA SHEET 202007.pdf

https://waf-e.dubudisk.com/anysolar.dubuplus.com/techsupport@anysolar.biz/O18Adzl/DubuDisk/www/Gen2/KXOB25-01X8F DATA SHEET 202007.pdf

Same size with different cell configurations.

As title, how I can get the most from this cells?

I'd like to use one, or two if necessary (price is not low), for a small outdoor project. Didn't found a lot on this kind of cells. I suppose that efficiency is a goal to get something.

I've a small MCU powered by a 100mA lipo (with BMS), a 3.3LDO and a small battery charger, approx. 1mAh drawing.

What's more efficient; use this solar chips to recharge battery? Or should I use battery as auxiliary power and get power from this chip?

Connection advises are welcome (by switching, charge p
ump or.. idk).
BTW, how many solar cells do you have to use for this or can you get more also.
 
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