Re: Which uses less power

On 2024-10-23 19:21, VanguardLH wrote:

"Carlos E.R." <robin_listas@es.invalid> wrote:
 

On 2024-10-23 03:04, VanguardLH wrote:

Chris <ithinkiam@gmail.com> wrote:
>

sms <scharf.steven@geemail.com> wrote:

On 10/21/2024 11:15 PM, Bill Powell wrote:

Which uses less of the phone's battery power on long trips?
>
Playing long podcasts with the Android speaker as the output?
Playing long podcasts with a Bluetooth speaker as the output instead?
>
Any idea?

>
Speaker wattage is about 3W.
>
Bluetooth uses about 2.5mW.
>
So the speaker uses more than 3000x the power.

>
Do you have a source?

>
Do you to refute?

>
I do not refute nor corroborate, so I would like a source either way :-)

 Me, too.  I'd like to know the basis for both claims.  Alas, there are
so many variables involve with unknown phones and BT/BLE devices
employed that the results are unpredictable.
 BLE devices go into low-power sleep mode when inactive.  Batteries in
BLE devices are typically much smaller (far less capacity) than the
battery in a phone.  But that's for BLE devices.  Unless you turn it
off, does the BT radio in the phone ever go into sleep mode?  No, not
when the phone itself goes into sleep mode, but if the BT radio alone
will go into sleep mode.

Low power BT does not transmits during silence, AFAIK.

 My reading of the OP's inquiry is that he is asking about power drain on
the phone's battery when using its speakers versus using the BT radio in
the phone to a BLE device.  BT isn't transmitting power, just a signal,
but the longer the BT radio is active the more power it consumes
assuming the BT radio in the phone ever goes into low-power sleep mode.
 From what I've found, the BT radio in the phone is either on or off, not
in a low-power sleep mode (that's just for BT devices).
 Since the OP wasn't asking about battery drain on the BT headset device,
but on the impact to the phone's battery when using BT, I did find:
 https://www.seinxon.com/blogs/blog-posts/does-bluetooth-drain-your-battery
 The article doesn't give a bio on Robert Triggs, or which of his
articles is cited.  Might be this guy:
 https://www.soundguys.com/author/roberttriggs/
 Note the OP only mentioned "Bluetooth".  Not which version of it.  He
didn't mention his phone, so we cannot lookup what BT versions it
supports.  We don't which versions of BT the BT headset uses, either.

Someone mentioned an app to measure power drain.

 Batteries lose capacity (coloumbs) over time even when not use, but more
when in-circuit than sitting on a shelf.  Be interesting to know if loss
of capacity in the phone's battery from BLE radio usage outstrips the
natural drain of the phone's battery.
 Also remember that it isn't just the BT radio in the phone that is
consuming power.  The CPU needs power to control the radio and the radio
protocol stack.  There is also chatter between the BT radio in the phone
to the BT device.  Once bonded to a BT device, the two endpoints need to
keep the channel alive by periodically passing packets even when no
traffic is being sent to the endpoints.
 https://www.link-labs.com/blog/bluetooth-zigbee-comparison
 That says the BLE radio consumes 10 to 100 mW while traditional BT
consumes 1 W: 10 to 100 times difference.  Again, we don't know which BT
is involved for the OP.  It also mentions packets are sent in bursts
using BLE, and the BLE device sleeps between bursts (but not if the
phone's BLE radio sleeps between bursts).
 So, then to compare BLE radio power consumption in the phone (to a BLE
device) versus using the phone's speaker power consumption, there are
several variable when using the speakers, like the volume level at the
speaker.  Playing at louder volume means more power consumed from the
phone's battery.  While phone speakers may be rated 1.5 to 3W (for
output power), input power would be higher (no speaker is 100%
efficient), but again affected by the volume level.  However, who
listens to music by putting their phone's speaker next to their ear to
play at low volume?  Earbuds don't need as nearly as much power to
produce the same volume level in the ear as opposed to audio from the
speaker in the phone.  Heavy bass uses more power.  More energy to push
the cone further.  Speaker sensitivity affects power consumption: a
lower-power rated speaker that is more efficient can produce the same
volume as a higher-power rated but less efficient speaker.  Headphones
are more energy efficient than speakers, but the OP probably does not
have a phone with a headphone jack, and why he asks about BT headphones
or ear buds.  The bigger the speaker, the more energy to move the larger
mass.  Design, components, and usage affect power consumption of the
speaker(s).
 Looks like the phone's internal speaker draws about 8 mW, on average,
but the variables above can produce varying results.  Meanwhile the BLE
radio in the phone will consume 10 to 100 mW of power which looks more
than for the internal speaker; however, you'd have to know how often are
the bursts and sleeps to average out or RMS the power consumption over
the time the BLE device is active.  There are no bursts with traditional
BT, so that type of radio in the phone would likely use nearly or more
power than the internal speaker.
 Besides, how many speakers are there in a phone?  One.  So forget about
stereo (left vs right) spatial differentiation in audio quality.  With
headphones (via jack or BT), you get stereo.

No, my phone does have stereo speakers, but you have to turn it 90 degrees (to horizontal).

 As others mentioned, probably the best way to gauge power consumption to
compare internal speakers against whatever BT version is used to the
BT/BLE headset is to monitor battery consumption.  Play the same media
for the same length of time, like 1 to 4 hours, once using the internal
speaker (with BT turned off) and another time using the BT/BLE headset.
A lot depends on volume level, density of the media, whether BT or BLE
is used, efficiency of the speaker and circuit design.  Start with a
fully charged phone battery each time to obviate the natural drain on
the battery even when idle.  The OP needs to determine how his
unidentified phone with its speakers fairs against using a BT/BLE
headset.  There are a LOT of variables in a vague scenario.

--
Cheers, Carlos.