Re: Solar power battery system for WRT54GS

miso@xxxxxxxxx hath wroth:

Like I said, I couldn't find a manual. However, it is uses a 12V wall
wart, what current does it draw?

The WRT54G and GS uses a switching regulator down to 3.3VDC. It will
run on anything from about 4VDC to about 18VDC. The regulator will
probably handle a higher voltage, but I'm worried about the input
filter cazapitor.

The current drain is:
Volts Amps
15 0.25
12 0.3
5 0.8
4 1.0
for about 4 watts dissipation. The actual current drain varies
somewhat with hardware version. This is for my V3.0 WRT54G.

The WRT54G/GS will run quite nicely directly from a 12V gel cell. For
charging, a small solar controller (i.e. Morningstar) will do just
fine.

The problem is that it burns about 4 watts continuously. To run for
24 hours without a charge (required for mid-winter operation), and
keep the battery at 75% charge, the 12v battery would need to be rated
at 30 A-hrs min. I threw together a spreadsheet for the purpose. It
was made for commercial and ham radio repeaters, but should work for
anything:
http://802.11junk.com/jeffl/rf-calc/solar-repeater-206.xls
Unfortunately, to recharge a 30 A-hr gel cell in one day or less
requires a 400watt solar array (non-tracking). The WRT54G will burn
94 watt-hrs/day. The solar array would need to equal that in order to
prevent the battery from running down. At 25 watt solar array would
do the job. oh-oh, I think I just found a mistake in the spreadsheet.

Some photos of a solar powered Wi-Fi box (not mine).
http://socalfreenet.org/lowbudgetsolar
http://socalfreenet.org/node/286
http://socalfreenet.org/node/287
http://socalfreenet.org/solarnode
http://socalfreenet.org/image/tid/20?from=15

--
Jeff Liebermann jeffl@xxxxxxxxxxxxxxxxxxxxxx
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
.

Relevant Pages

  • Re: Solar power battery system for WRT54GS
    ... The WRT54G will burn ... The solar array would need to equal that in order to ... prevent the battery from running down. ... Note that even with a 40 A-Hr battery and a 50 watt solar array, ...
    (alt.internet.wireless)
  • Re: Solar power battery system for WRT54GS
    ... I think the input capacitor won't be an ... Throw enough money at the input cap and the problen will be ... The WRT54G and GS uses a switching regulator down to 3.3VDC. ... The solar array would need to equal that in order to ...
    (alt.internet.wireless)