a good thick copper wire to connect the panel to the battery.
As I have already mentioned, during a short circuit batteries
can create quick and powerful current spikes that will melt
wires. The fuse should take the beating but play it safe with
something like AWG 17 (1.15mm) or thicker. There are also
considerations for proper wire gauge that take into account
wire length, voltage and current. There are plenty of places
online that provide formulas and information on wire selection.
couple of rules apply. Good ventilation is a must. You should
have vent holes on top of the enclosure [Fig 3]. Hydrogen
is lighter than air and will collect at the top of your box
if there is a leak.
enclosure is probably not the best idea. You could short circuit
the battery if you touch the metal with the wire terminals.
Short circuiting a 12V battery can cause premature death.
your battery enclosure in a dry area.
place has a great selection of equipment enclosures - http://www.polycase.com/
got mine at the swap meet [Fig. 5]. Three used 12V 7Ah batteries
for $5 U.S. Not a bad deal. If you are buying used look for
cracks in the plastic. Explosive gas may leak through the
cracks (although there may be cracks that you can't even spot
with a naked eye). A new battery is a better and safer choice.
can get fancy and connect several batteries in parallel to
increase capacity. This is done by connecting any number of
batteries' positive to positive leads and negative to negative
leads. Just remember that this should be done with new batteries
only. Otherwise you are reducing the used battery lifespan.
single 7Ah battery should be enough to run your WRT54G for
Fig. 5 12V 7Ah battery