I can power my project through the USB just fine. However, when I connect it to my battery, a 5V/1A Li-Ion 2200mAh (Powerpack for charging phones) , the battery dies after a few seconds. The voltage jumps up and down, then goes to 0V. If I disconnect the battery and connect it again, it runs for a few seconds again before stopping.
However, the battery can charge my Samsung Galaxy S4 phone without any problems.
I have a GPS, SD Card writer, compass and a pressure sensor connected to a pro mini 3.3V. The load is not that high I think.
I tried a different brand. The same problem, but now it turns off much faster.
I just realized that it might be a build in feature of the batteries. They are for charging phones. When charging, they turn on some leds to indicate the battery status. Could the battery power down by itself if the load is to low in order to save battery life?
Try a completely different type of battery - for example a few NiMh AA cells that give the same voltage.
And rig up a circuit with a resistor that draws the same current as the Arduino board and see how long the phone battery can provide current in that while maintaining the voltage.
A phone battery charger will expect to see a demand for 0.5A from the phone - substantially
less than this and it will assume the battery is fully charge and switch itself off (to save itself
for the next phone I presume)
The moral is use a phone charger battery pack only for charging phones.
What you need is a simple battery pack of a suitable voltage.
MarkT:
A phone battery charger will expect to see a demand for 0.5A from the phone - substantially
less than this and it will assume the battery is fully charge and switch itself off (to save itself
for the next phone I presume)
The moral is use a phone charger battery pack only for charging phones.
What you need is a simple battery pack of a suitable voltage.
Time to break out your maker skills. You could crack open the case, get to the power leads from the battery, and wire them to your own 5V regulator. Then you could still use the charging circuit on the battery pack to charge it, and use your regulator to power your projects (although lithium battery systems usually count the mA/h drawn from them to figure out when they need to be recharged, and you might bypass the current measurement circuit with this approach.
A 6 volt lead-acid gel battery should work great as a power supply for an Arduino. You could feed it directly into Vin, or add a 5 volt regulator and then feed it into the regulated power in.
DuncanC:
Time to break out your maker skills. You could crack open the case, get to the power leads from the battery, and wire them to your own 5V regulator.
//CUT//
Remember, the standard USB Power bank has 1 cell Lithium battery inside (3.2-4.2V) and the power bank has a boost-converter that makes the 5V, so opening the box won't help much.
The cheaper power banks that have no power button, does not turn off. I have some very simple ones, and the boost-converter runs constantly in those - and it can regain a charge for quite some time (over a month)
I played around with some resistors to keep the battery from going to sleep. It worked but took to much space for my project. Already got everything soldered onto a proto-board.
I returned the batteries to the store. Got refunded for both power banks. Will just use a couple of regular AA batteries for now.
Thought a power bank for charging phones would be great. Cheap with lots of power and easy of use and recharge. Never knew they would be this tricky to get to work.