Batteries; Getting Wired - US Amps AX Installation Manual

CARE AND FEEDING OF YOUR BATTERIES
As mentioned before, most batteries are built for the relatively light chore of starting the
engine. Unless you have the room and ambition to install an upgraded high-powered alternator,
your system current requirements may exceed the charging capability of your car's electrical
system. When this happens, you have to rely on the vehicle battery(s) to make up the
difference. Another factor to consider is voltage. Although the electrical system is considered to
be "12 volt", the battery, when healthy, actually "rests" at 12.6 volts. The average alternator
"puts out" 14.4 volts when the engine is on, because it is necessary to "feed" a battery higher
voltage in order for it to charge.

GETTING WIRED:

Once you have established the current needs of your system, it will be of the UTMOST
IMPORTANCE to properly fuse the amplifier. Remember, power connections are always the last
thing. There cannot be enough emphasis placed on the importance of proper fusing. Fuses
prevent catastrophes. Always fuse each U.S.Amp product at or less than the recom-
mended amperage. Another major consideration is wire. If you wish to build a truly high-
powered system, you must take into account the total amperage requirements of the system
and select your wire gauge accordingly. The following chart can be used as a guide:
WIRE GAUGE and AMPERAGE Guide:
AWG 14 30 Amps
AWG 13 35 Amps
AWG 10 45 Amps
AWG 8 60 Amps
These are real numbers, right out of the 1951 U.S.Federal Electronics Code Book.
It takes real wire to do real work.
For each 100 watts, when playing music, count on 10 amps average of average current draw.
3
AWG 6 80 Amps
AWG 4 105 Amps
AWG 2 135 Amps
AWG 1 160 Amps
AWG 0 190 Amps
AWG 00 215 Amps
AWG 000 245 Amps
AWG 0000 275 Amps