# Short Battery Life

#### jack0987

##### Member
Edit, the solder pad should be bridged to power the board.
I reconnected the power LED. Please see image.

What should be bridged?
Do you mean the LED pad?

#### Pommie

##### Well-Known Member
In the schematic it's labeled SJ1 but your board doesn't have any component names. The only thing that looks like a solder bridge is the thing in the white box near the top GND pin. If that is the bridge then it should be connected to pin 5 (top left) of the regulator. The bridge is there so you can disconnect the regulator and use a more efficient one for lower power usage.

Mike.

#### jack0987

##### Member
Right now this is very unclear to me.
I'll give it another go tomorrow.
In the meantime, plese have a look at this:

https://www.instructables.com/id/Arduino-low-Project-and-code/

Right now, I am still using the onboard regulator to test the ma.
Was planning to do that last or I have to use a lot of jumpers to go from the USB interface to the mini.

#### be80be

##### Well-Known Member
The solder bridge is on the back on most boards

#### Pommie

##### Well-Known Member
That instructable confirms the position of your solder jumper. Also shows how to put Arduino in sleep mode.

Mike.

#### jack0987

##### Member
The solder bridge is on the back on most boards
This is back of a similar board I have.
(please over look my messy soldering.)

#### jack0987

##### Member
That instructable confirms the position of your solder jumper. Also shows how to put Arduino in sleep mode.

Mike.
I had my Arduino Pro Mini connected wrong and now have it running again so I guess I am now back online.

I have also disconnected the the power LED.

My AmpMeter is connected to the RAW voltage input feed by the batteries.
Adding this code, the power usage dropped from 20.4ma to 16.5ma.

Code:
#include <LowPower.h>

LowPower.powerDown(SLEEP_2S, ADC_OFF, BOD_OFF);
With the power LED disconnected, it dropped from 16.5ma to 16.4ma. Not much of a savings.

As I see it, if I now proceed to remove the voltage regulator, there will be nothing to power the board.
Will I still be able to power and program it using the USB interface?

#### Pommie

##### Well-Known Member
You replace the regulator with a more efficient regulator. If you remove it then you are correct, nothing will power your board.

Mike.

#### Pommie

##### Well-Known Member
If you connect your new, more efficient regulator between USB in and your processor then you'll still be able to program via USB.

Mike.

#### be80be

##### Well-Known Member
The regulator that it said it has is not a. Bad one it has good specks

#### jack0987

##### Member
The regulator that it said it has is not a. Bad one it has good specks
Thanks. I will revist this later.

For now, I am thinking that some code changes may help a lot with power savings.

What I have in mind is to use an interrupt to wake the computer.
I will google this area as well.

#### Nigel Goodwin

##### Super Moderator
With the power LED disconnected, it dropped from 16.5ma to 16.4ma. Not much of a savings.
Are you disconnected the transmitter, and putting the Arduino to sleep? - those are the important things - disconnecting the LED will make a massive saving once you've already done that.

#### jack0987

##### Member
Are you disconnected the transmitter, and putting the Arduino to sleep? - those are the important things - disconnecting the LED will make a massive saving once you've already done that.
Come to think of it, right now I am only putting the processor to sleep for (I think) only 2 seconds for each run of the loop.
Mike suggested I look at the transceiver data sheet on how to shut it down but I have not figured it out yet.

#### Nigel Goodwin

##### Super Moderator
Come to think of it, right now I am only putting the processor to sleep for (I think) only 2 seconds for each run of the loop.
Mike suggested I look at the transceiver data sheet on how to shut it down but I have not figured it out yet.
Switch the power to it, using an I/O pin, and either a transistor or FET switch. Even if it has a shut-off capability, they still waste a certain amount of power.

I would also suggest you increase the sleep time (at least temporarily), as repeatedly coming out of sleep while measuring makes it more difficult to measure - to measure mine I temporarily switch the TMR off, so it never comes out of sleep. Then I measure again, without sleep at all, then measure how long it spends out of sleep during normal functioning (using a scope) - a bit of simple maths then gives you the average current consumption.

In my case I was amazed how little time it spends out of sleep, only a few micro-seconds out of every second.

#### jack0987

##### Member
Switch the power to it, using an I/O pin, and either a transistor or FET switch. Even if it has a shut-off capability, they still waste a certain amount of power.

I would also suggest you increase the sleep time (at least temporarily), as repeatedly coming out of sleep while measuring makes it more difficult to measure - to measure mine I temporarily switch the TMR off, so it never comes out of sleep. Then I measure again, without sleep at all, then measure how long it spends out of sleep during normal functioning (using a scope) - a bit of simple maths then gives you the average current consumption.

In my case I was amazed how little time it spends out of sleep, only a few micro-seconds out of every second.
Thanks. I will try that out.

#### jack0987

##### Member
Switch the power to it, using an I/O pin, and either a transistor or FET switch. Even if it has a shut-off capability, they still waste a certain amount of power.
I don't think you are going to believe this. As quick test I just simply disconnected the transceivers power jumper and the usage jumped up from 16.4ma to 19.7ma.

#### Pommie

##### Well-Known Member
The transceiver only uses 1uA when in sleep mode.

Mike.

#### jack0987

##### Member
The transceiver only uses 1uA when in sleep mode.

Mike.
Thanks. mike. The usage is down below 1ma now and wondering what may be the best way to power the thing. I would like to use AA batteries because they are easy to come by.