Battery power supply

Hello,

I'm more of a software-guy but I have a microcontroller project
underway that is intended to run off battery power. The MCU draws
about 30mA at 3V and I had intended to run this off a CR2450 battery
that is said to provide about 600mAh at 3V. I thought this would give
an operating time of around 20h, which is acceptable.

However, when I'm reading the specs for a CR2450 battery, it says the
maximum continuous discharge current is only 2mAh! The wikipedia page
for battery types lists the CR2450 as recommended for "high" current
devices around 30mA, so I'm a bit confused...

Is the CR2450 adequate for my application, or do I need to use a
different kind of battery, maybe two AAA or something like that, which
are able to give more current?

Thankful for educational advice!

 

[Nobody]

On Wed, 11 Feb 2009 01:01:55 -0800, manenidittoga wrote:

I'm more of a software-guy but I have a microcontroller project
underway that is intended to run off battery power. The MCU draws
about 30mA at 3V and I had intended to run this off a CR2450 battery
that is said to provide about 600mAh at 3V. I thought this would give
an operating time of around 20h, which is acceptable.

However, when I'm reading the specs for a CR2450 battery, it says the
maximum continuous discharge current is only 2mAh! The wikipedia page
for battery types lists the CR2450 as recommended for "high" current
devices around 30mA, so I'm a bit confused...

Is the CR2450 adequate for my application, or do I need to use a
different kind of battery, maybe two AAA or something like that, which
are able to give more current?

CR2450 isn't adequate for 30mA continuous. The data sheet suggests that
you can draw 30mA pulses (15 sec), but the output will drop to 2-2.5V
(depending upon temperature) at that load.

Using 2x AAA sounds about right. "Button" cells are generally designed for
low (average) current, long life usage.

The "30mA pulsed" usage is for things like central-locking remotes, where
you might have a few short pulses each day.

 

On 11 Feb, 12:59, Nobody <nob...@nowhere.com> wrote:

CR2450 isn't adequate for 30mA continuous. The data sheet suggests that
you can draw 30mA pulses (15 sec), but the output will drop to 2-2.5V
(depending upon temperature) at that load.

Using 2x AAA sounds about right. "Button" cells are generally designed for
low (average) current, long life usage.

The "30mA pulsed" usage is for things like central-locking remotes, where
you might have a few short pulses each day.

Ah, 'tis as I feared...

My application has to be active a bit longer than a mere 15seconds so
button cells are out then...And unfortunately, so are the enclosures
I've been eyeing since they don't have the capacity to accomodate AAA
batteries

But thanks for the help, much appreciated!