Keith Lofstrom wrote:
> I fiddled a bit with the "Auxilliary Power Supply DC 12V" input to
> my FIOS BBU.
>
> The barrel connector seems to be a 0.15 inch barrel (approximately
> 6mm), center positive. I clipped the connector and cable off an
> obsolete wall wart, and proceeded. This is the same power connector
> as some of the older Nokia cell phones, IIRC.
>
> I set up a lab bench power supply with current and voltage limits,
> and connected it to the cable. When I increased the voltage above
> 12.5V , the "Auxilliary Power Source" light on the front panel lit
> up. The BBU drew less than 10mA. I dialed it up to 13.5V, about
> what a car battery puts out, and set the current limit to 5 amps.
> Since the unit draws 20W from the line in normal operation, I
> assumed that would be enough.
>
> I pulled the line power input to the BBU, the unit went on battery
> as intended. I pulled the internal battery connection, hoping it
> would use the auxiliary power instead of the internal battery,
> and the BBU shut down, without drawing current from the auxiliary
> jack and bench supply. It might have been a startup surge, so I
> tried again with 0.086 farads across the supply. Again, shut
> down, no current from the bench supply. I don't want to try a car
> battery directly, too much current if something shorts.
>
> So - a mystery. Perhaps there is some protocol on the wire to the
> approved external device. For extended life, use an external UPS
> on the line input, I guess.
>
> Keith
>
Keith Lofstrom
According to what I have read (online manual for the unit I have
(CPL28U12) - you didn't mention your model) ... you are/were almost
there ... there is (again, on my model) a button marked "Battery
Emergency Use" (next to the Alarm Silence button), which (although
Verizon fails to mention it in their documentation) is intended for
emergency use as follows ...
"Press the button once to use the reserve battery capacity and/or
the auxiliary battery capacity after low battery shutdown. The unit
will emit a confirmation beep."
... as an additional note, the battery is a 12 V 7.2 AHr battery - I am
not sure what that would equal in amps from a bench power supply, but I
don't think that was the cause of the NoGo in your test, as you didn't
mention pushing the Battery Emergency Use button.
Thanks for the input - that sounds (correct me if I am wrong) as if one
were to connect the free ends (say with alligator clips attached?) of a
cable of the description you gave above to a fully charged 12 V 7.2 AHr
battery (i.e., the same type as the one in the unit itself), and the
barrel end of that cable to the BBU auxiliary port provided, one could
be good to go? First making sure polarity on the cable was correct, of
course.
Regards
Fred James
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