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Battery Consumption

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Aug 16, 2020
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Hi guys,

I am new here and still not an engineer and have not much knowledge in Battery / electricity but have a major project I am working on and would be very happy to get some answers..

I am trying to build a machine that is using a spin motor that work periodically in set times (650 spins a day: 10 turn per minute than a few minutes rest) by a simple electric circuit and position it in a place without electricity connection.

The manufacture of the motor sent me these consumption values: Voltage: 3 - 12VDC, Current @ maximum efficiency: 0.17A. On the machines provided power supply I have the follow values: 3v / 1.2A

They also claim that when it is operated by strong 2 x AA batteries it will be able to work for around 8-9 weeks (defined amount of movements periodically in a day - around 650 turns total).

I try to find a way to operate the machine longer without any need to change the batteries every second month.

I try to look at a solution of connecting a 40000mAh portable usb power bank to it through a 'step down voltage device' that will provide it the right amount of Voltage and Ampere.

Like this one:

My questions are:

Is it true that in these settings with a 40000mAh power bank, the machine will be able to run 20 times longer than when it will when running on 2x AA 2000mAh batteries ?

Is it safe to have the machine connected to such a power bank constantly and have it stored in a close place ?

Thanks a lot for your time !

A larger battery will last longer but not necessarily as long as the AH rating alone would suggest. Batteries also have a 'self discharge' property by which they lose capacity over time even when nothing is being drawn from them. Also bear in mind that the ratings on 'power bank' devices are generally exaggerated by the manufacturer, personally I would assume they really have no more than about half of what they claim.

If you run a voltage converter from the battery it will consume some power itself, even with no load on it so the battery life would be further reduced. You really need a battery with higher capacity and a power supply that completely disconnects until the motor has to turn, for that you would have to show us the schematic for the machine so we can advise on the best method to use.


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