Does anybody make a Li-PO charger circuit with a 5V input and a low current output for such a small battery? The battery in a cell phone is much larger and uses a much higher charging current.

I don't know for sure, but I believe the Adafruit system I linked to earlier does just that. They sell it for use with batteries down as low as 150mAh, so I certainly HOPE that they've got charging current chosen appropriately for small batteries!

 

The Adafruit charger can charge at 100mA or if you add one drop of solder then it charges at 500mA.

 

I think it's a 700 mAh battery, not 700 mA. It can probably provide a few amps of current.

That's what I meant.

 

OK so the power module will boost the 3.7, 700ma volt battery to 5 volts to run a standard USB charger to charge the smaller 280ma Lipo.
That will work but how are you charging the 3.7,700ma battery?

Okay so I think I am going to use a TP4056 to charge the power bank and I will be using a TE110 for the usb charger that will be charging the battery for the device. I'm hoping it can provide enough current and at least one full charge. The good quality image is the battery I desire to use in the power bank, The Internal Battery jpeg is the battery inside the device I want to charge

 

This is why you need to be careful with LiPo batteries. granted he did bite it but they don't handle abuse well at all.

 

Just order at aliexpress:
https://www.aliexpress.com/item/4-2...ter-Step-up-Module-18650-UPS/32826939778.html
Alain63720

 

Search eBay for TP4056. Here’s a link sorted by price: https://preview.tinyurl.com/yafdtqga