Re: [Starlink] Starlink power use & satellite tracking

[Jonathan Bennett <jonathanbennett@hackaday.com>]

[-- Attachment #1.1: Type: text/plain, Size: 5876 bytes --]

I've run my 1st gen dishy on the road, and discovered that the inverter
needs to be a true sine-wave to get reasonable efficiency from the power
brick. With mine, the device just bootlooped on a modified sine wave
inverter, presumably because the brick couldn't quite push enough power to
complete boot.

Jonathan Bennett


On Thu, Feb 16, 2023, 5:14 PM Nathan Owens via Starlink <
starlink@lists.bufferbloat.net> wrote:

> I should add, I can actually run the HP dish w/o the router using the same
> setup, but when it's obstructed it spikes to ~190W AC, which if it lasts
> more than 60s does trip my car E-Fuse. I'll be adding a small battery as a
> buffer, which should be able to pull 150W DC from my car, and handle the HP
> dish continuous draw of 65-95W.
>
> On Thu, Feb 16, 2023 at 3:12 PM Nathan Owens <nathan@nathan.io> wrote:
>
>> I ran a Round Dishy in my car for a long time, along with the router,
>> using a 300W inverter. My car is rated for 12A continuous, 16A peak. Per my
>> Kill-A-Watt, it drew on the order of 30-50W, sometimes spiking to 80-90W
>> when obstructed/booting. My inverter is 90% efficient, and never tripped my
>> car 12v E-fuse. The V3 dish is more efficient, and uses less power.
>>
>> On Thu, Feb 16, 2023 at 3:08 PM Ulrich Speidel via Starlink <
>> starlink@lists.bufferbloat.net> wrote:
>>
>>> In the aftermath of our cyclone here, I got dragged out for a bit of
>>> media comment and, downstream, a few questions came up on dishy power use.
>>> Here's what I know and can glean - comments welcome:
>>>
>>>    - Starlink's own specs say 50-75 W "Average Power Usage":
>>>    https://www.starlink.com/specifications. But that's average, not
>>>    peak, and peak is what matters when people start recommending that Starlink
>>>    could be run out of a small inverter and a car battery in a disaster.
>>>    - Small inverters usually come with cigarette lighter cables, and
>>>    cigarette lighter sockets are typically fused with 8 or 10 A fuses. That
>>>    puts maximum safe power outputs in the 96W to 130-something W range
>>>    depending on battery voltage.
>>>    - Our lab's "RV" subscription rectangular dishy & router regularly
>>>    clocks in at around 80-100 W, and I've seen it go as high as 108 W on one
>>>    occasion. I've also seen it go as low as 30 W for the first time last night.
>>>    - I have a user report from an older round dishy owner having seen
>>>    up to 200 W on occasion.
>>>    - Assuming conservatively 90% inverter efficiency, that could mean
>>>    up to ~120W and maybe more for the rectangular version and over 220 W for
>>>    the circular one.
>>>    - If dishy goes over cigarette lighter fuse capacity, people may
>>>    lose their ability to charge phones from their car - also a critical
>>>    capability in a disaster.
>>>       - Not everyone takes kindly to the suggestion that advising
>>>       inverter + car battery use could potentially be counterproductive.
>>>       - So, what's the peak power use you have seen on your version of
>>>    dishy?
>>>    - It appears that the current mode of operation here is that dishy
>>>    uses several satellites in parallel if these can all see a gateway and have
>>>    capacity to carry traffic.
>>>    - So for us in urban Auckland with few Starlink users in the cell
>>>       and three gateways in the vicinity, our dishy is spoiled for choice and
>>>       usually gets to use maybe three or more satellites at once. That takes a
>>>       corresponding amount of power but also means great data rates a lot of the
>>>       time.
>>>       - For a rural user with more Starlink users in the cell and
>>>       further away from gateways, the satellites that the cell can see and that
>>>       can also see a gateway may be fewer in number. This means dishy only gets
>>>       to talk to maybe one or two birds at a time and so uses a lot less power,
>>>       and you get more average data rates there.
>>>    - If this is so, then it begs a question:
>>>       - If Starlink could cap the number of satellites dishy can use in
>>>       an emergency area, they would be able to keep your fuse intact. Should they
>>>       aim for that, even if it means that you might see lower data rates in a
>>>       situation when many people depend on one unit?
>>>
>>> Starlink is currently being touted as THE comms solution for emergencies
>>> as large swathes of NZ's northern and eastern North Island remain without
>>> terrestrial or mobile Internet coverage after cyclone Gabrielle. This is
>>> the outage map of one of the larger mobile phone providers just for these
>>> areas:
>>>
>>> Most of these are due to power outages to sites, but there are quite a
>>> few backhaul cable issues as well.
>>>
>>> One of the biggest problems is that electronic payment systems don't
>>> work without Internet. In our largely cashless society, this is leading to
>>> situations where emergency services can't refuel their vehicles because
>>> their fuel cards won't work, supermarkets and other stores can't sell
>>> anything because customers have no means of paying, and the air force is
>>> flying in hard cash in order to help the locals buy food.
>>>
>>> --
>>> ****************************************************************
>>> Dr. Ulrich Speidel
>>>
>>> School of Computer Science
>>>
>>> Room 303S.594 (City Campus)
>>>
>>> The University of Aucklandu.speidel@auckland.ac.nz http://www.cs.auckland.ac.nz/~ulrich/
>>> ****************************************************************
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> Starlink mailing list
>>> Starlink@lists.bufferbloat.net
>>> https://lists.bufferbloat.net/listinfo/starlink
>>>
>> _______________________________________________
> Starlink mailing list
> Starlink@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/starlink
>

[-- Attachment #1.2: Type: text/html, Size: 8133 bytes --]

[-- Attachment #2: T7iUkprxXR60409x.png --]
[-- Type: image/png, Size: 172632 bytes --]

[-- Attachment #3: F2CEH9TnkDh1Wrc0.png --]
[-- Type: image/png, Size: 366212 bytes --]