I have a LiPo Charger/Booster - 5V/1A (PRT-14411) , which is connected to a LiPo battery via the jst connector. The circuit powers a small weather station, with a BME180 breakout board and a TFT screen (ST7735). There are a couple of LEDs and also an AS3935 lightning detector board. Anyway, everything works until the battery is fully empty, then it shuts off (obviously)
Then, when I plug in a charger, the blue charging LED comes on, and the red boost LED, but for some reason no power is sent through the 5V pin to power the project, it shows as dead on my multimeter. But then when I test it with a multimeter a few times, it starts reading as 5V again.
I have an external switch wired to the board, and I know it says to get a reliable charge you should turn the switch on and draw less than 20mA during charging. However, the display consumes like 60-70mA so I have to break that rule if I leave the switch on.
Am I tricking the chip into not providing power somehow? Or is something else going on? I have tried the circuit with 2 different chips and the same thing happens. It works fine, battery dies, shuts off, charges fine - and then no output voltage until I screw with the terminals with my multimeter.
Any ideas? Thanks!!
What size is the battery? https://learn.sparkfun.com/tutorials/sp … -a-battery
Sharing a photo of the set-up might help too
It is the Lithium Ion Battery - 2Ah (PRT-13855)
The setup is a little messy but here are some pics I realize the little onboard switch is on but that is for trouble shooting I usually have it to off since I connected an external switch. Also the battery is located under the Mega:
A point of clarification: I leave the weather station on until the LiPo battery dies (or at least the whole thing turned off). Then, I charge it with a 5V - 1A wall charger wired to the +/- pins behind the USB port. I have the switch off (external switch and onboard switch) while charging since the circuit draws close to 70 mA. But, after charging (the blue LED goes off) I am not getting any power from the 5v pin on the board. Those output pins are wired into the Mega’s VIN pin and ground. I did have them connected to a barrel jack that plugged into the Mega but after running into issues with the charging I switched that up to go directly into Vin.
Another detail - when charging (with switches in the Off position) I am still getting a dim red light from the boost LED. Maybe I need to wire the external switch to the EN and Gnd pins instead of +/- pins? Anyway, I am stumped.
Well, I could not figure out why the board would not activate after charging. I tried wiring the ENABLE pin to my switch instead of to the external switch pins. Still no dice. So I swapped out the entire board for an Adafruit Powerboost 500C - and it works perfectly. The switch connects the PB’s Enable pin to ground (like the Sparkfun board). I think the difference is the load sharing capability of the Adafruit board. You can run the circuit from the USB input and still charge the battery. Or you can turn off the switch and still charge the battery. I don’t really know, but in any case the project works now.
Glad to hear that. Best of luck with your project!
