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Solar Charger Prod: 390 (MCP73871)
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Solar Charger Prod: 390 (MCP73871)

by antoniob on Mon Sep 20, 2021 3:02 am

I am currently using the "Solar Charger, SKU 390 (MCP73871 based)" for remote solar power back to field sensors.
I am recently experiencing issues. I been unable to find similar problems in the forums.

The /PG LED and the /CHG LED's are either OFF or flashing. never steady state. I am unable to find any reference to flashing LED's in the data for the MCP73871 device.
Is this normal or is the module faulty. The battery seems to be fine and the Solar Panel in full sunlight reads 5.8V.

Thanks.

antoniob
 
Posts: 28
Joined: Tue Jul 09, 2013 2:47 am

Re: Solar Charger Prod: 390 (MCP73871)

by mikeysklar on Mon Sep 20, 2021 6:45 pm

@antoniob,

This sound like a possible connection issue. Can you post photos of the solar charger soldering and relevant connections? What voltage range have you been seeing on the battery itself?

How long have you been using the charger?

mikeysklar
 
Posts: 5767
Joined: Mon Aug 01, 2016 8:10 pm

Re: Solar Charger Prod: 390 (MCP73871)

by antoniob on Mon Sep 20, 2021 7:11 pm

The measured DC IN from the Solar panel is 5.48V, steady, measurement taken at the "DC IN" terminals.
The LiPo battery (3.7V 4400mAh) voltage, measurement taken at the "BATT" terminals is 3.88V, steady.
The "LOAD" output, with solar feed is measures 5.4VDC, with no solar feed, 3.8VDC.
The "LOAD" connection is fed to an Adafruit TPS63060 Boost/Buck Converter, the output, measured at 5.1VDC, then feeds an ESP32 module and two sensor boards.
The LEDs flash at a rate which appears correlates with the amount of power being fed from the solar panel. As the solar feed drops, the flashing rate of the LEDs reduces...
The electronics are fitted inside an IP65 housing.
I am unable to supply a photo as the unit is currently at the office and I am working from home.
All measurements were taken at 5:10pm, 20 Sep 2021.
The charging module, battery and TPS converter have been in operation for about 3 months.
Any assistance appreciated.
Cheers.

antoniob
 
Posts: 28
Joined: Tue Jul 09, 2013 2:47 am

Re: Solar Charger Prod: 390 (MCP73871)

by mikeysklar on Tue Sep 21, 2021 4:56 pm

The voltage values you are reading all see well within tolerances and what you would hope to see.

The flashing has been seen by other users. As to what is happening (charging, checking and switching modes) based on battery voltage and light level. Take a look at the last thread we had on this:

viewtopic.php?f=19&t=158677

mikeysklar
 
Posts: 5767
Joined: Mon Aug 01, 2016 8:10 pm

Please be positive and constructive with your questions and comments.