Voltage dropping problems if cheap components are used

The following are some examples of the kind of Voltage drop expected across various gauges of wire on a 100 Watt load (12 Volt X 8.33 Amps).

These Voltage drops are in addition to the drops across the battery tabs, the welds, thermostat, circuit breaker or fuse or polyswitch & the outside connector. For a 12 Volt device on a nominal 13.2 Volt (11 cell) battery you don't have to worry as much about Voltage drop because you started out with more than you needed, but on a nominal 12 Volt battery, it is much more critical to try to not drop the Voltage too much.

Here is a realistic scenario of total Voltage drop on a 12 Volt NiCad or NiMH battery (using a 100 Watt load).
0.1388 across 2 feet of 16 gauge external cable.
0.0230 across 9 nickel tabs if they are 0.010" thick X 0.5" wide X 1.5" long
0.0300 across thermostats (2 Pepi Model B or N-1 in parallel) guestimate.
0.0300 across a quality in-line fuse.
0.0200 across an XLR connector.
0.2418 total Voltage dropped on a 100 Watt load.

>> Ohm's law calculator.

>> Wire gauge matrix & Voltage drop calculator.