# Anyone come across an electronic battery?

#### cjdelphi

Oct 26, 2011
1,166
if there isnt one, I'm going to think up one and build it, I'm thinking a microcontroller and a screen, set the output voltage 3/5/9/12v etc, and then you tell it how big the battery is, eg 100ma

it then runs whatever electronics you want and delivers 100ma of current when finished it tells you how long it took to consume that current..

if it's been done no point re inventing the wheel

#### Harald Kapp

##### Moderator
Moderator
Nov 17, 2011
13,054
you tell it how big the battery is, eg 100ma
A battery's capacity is measured in mAh, not mA. Do you mean 100 mAh?

it then runs whatever electronics you want and delivers 100ma of current
You can't deliver a set voltage and current at the same time. The current drawn by the load will depend on the load. You only set the voltage.
(under special circumstances you can set the current, but then the voltage will vary depending on the load).

I think you haven't worked out the concept of what you want to achieve.
Where's the power to come from?
What if the electronics requires more or less than 100 mA?
How will you define the point to determine "when [it is] finished "?

I recommend you go to battery university and study a bit more about batteries, charging and discharging.

if it's been done no point re inventing the wheel
I'm almost certain that it has been invented before - if only I knew what it is you want to achieve.

#### cjdelphi

Oct 26, 2011
1,166
A battery's capacity is measured in mAh, not mA. Do you mean 100 mAh?

You can't deliver a set voltage and current at the same time. The current drawn by the load will depend on the load. You only set the voltage.
(under special circumstances you can set the current, but then the voltage will vary depending on the load).

I think you haven't worked out the concept of what you want to achieve.
Where's the power to come from?
What if the electronics requires more or less than 100 mA?
How will you define the point to determine "when [it is] finished "?

I recommend you go to battery university and study a bit more about batteries, charging and discharging.

I'm almost certain that it has been invented before - if only I knew what it is you want to achieve.

yes not thought it out properly, I just want to know if an electronic battery exists, I'll be using a shunt and measure the voltage drop across, when its consumer a certain amount of current, cut it off and display how long it ran for

I want to test the efficiency of several circuits so defining a limit and seeing how long it takes, I won't be controlling the current, it will take whatever it needs I'll just be timing it...

either way I can't find one when I search for one...

#### cjdelphi

Oct 26, 2011
1,166
so I would dial in 100mah select 5v

when 100ma has been delivered be 1 hour or 30 seconds, it then says how long it took to consume that current, simple as that...

that's why I'm asking I can't find one but sounds like it should exist

#### Alec_t

Jul 7, 2015
3,330
Sounds a simple enough task for a micro, e.g. the ubiquitous Arduino. Have a PWM-controlled voltage source, a current shunt, integrate the voltage across the shunt and switch off the voltage source when the integral reaches a predetermined value.

#### kellys_eye

Jun 25, 2010
5,469
Therre already exists a panel meter that monitors voltage, current and power consumed (over time). This does what you want to (seemingly) achieve except for generating the power itself which is a basic current-limiting power supply.

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