Low Current Power Bank

[Alan Wood 4Participant @alanwood4]

While working on some very low current portable Arduino applications using the Seeed Xiao I opted to use an off the shelf power bank as the power source.   I ran into the problem that the majority of power banks need a current draw of around 50mA to stay ‘on’.   A big resistor was looming until in the course of my frustration I found that a Charmast branded 10Ahr pack has a soft work around.   Plug your low current device into the USB-C output, switch on and then hold the power button for a few seconds.   The last digit of the capacity display will begin to cycle round its segments and the unit will stay on.

[SillyOldDufferModerator @sillyoldduffer]

As Alan reports, a power bank (phone recharger) may not be best choice for running a low-power Arduino.  Power banks are designed to wallop power as fast as possible into a flat smart phone battery, not to trickle milliamps, and their electronics may be unhelpful!  Like as not they are designed to stop charging the phone when it’s only taking milliamps,which usually means the phone battery is full.

A plain 6V battery would be my first choice.

On the other hand, Alan is on to something!  Power-banks look to the cheapest rechargeable batteries on the market, and they plug straight into any USB device.  Good idea then, provided they can be cajoled into trickling!

Dave

 

[bernard towersParticipant @bernardtowers37738]

surely a battery only gives up whats demanded of it?

[bernard towers]

On bernard towers Said:

surely a battery only gives up whats demanded of it?

The underlying problem, I would posit, is that the rechargeable cell [or battery of cells] typically only charges to three point something Volts, and therefore the Power Bank has to incorporate Boost circuitry to provide 5v

Too clever by half

MichaelG.

 

 

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