What size fuse do I need? Start with one rule: a fuse protects the wire, not the device. It has to blow before the cable overheats, but it shouldn’t blow during normal operation. Here’s how to size fuses for battery cables, inverters, DC loads and solar strings. Electrical work can be dangerous: follow the manual, […]
What size inverter do I need? Bigger isn’t automatically better. An oversized inverter wastes battery through higher idle draw and needs thicker cable. An undersized one trips when the fridge compressor kicks on. Here’s a five-step method and three worked examples. Electrical work can be dangerous: follow the manual, fuse and size every cable correctly, […]
Series vs parallel is the first wiring choice for any battery bank or solar array. The rule is short. Series adds voltage. Parallel adds current (amp-hours). Total energy (Wh) or power (W) is the same either way. What changes is the voltage and current your cables, charge controller and inverter have to handle. Electrical work […]
Volts, amps and watts explained simply: volts are electrical pressure, amps are flow, and watts are the work done, and the U.S. Department of Energy defines wattage as volts times amps. This guide uses a water analogy, one formula, and examples you’ll actually run into with solar and batteries, so a battery label in amp-hours […]
A wire gauge chart for 12V, 24V and 48V systems needs two numbers for each copper size: ampacity, from NEC Table 310.16, and resistance per foot, from NEC Chapter 9 Table 8. Ampacity is how much current the wire can carry without overheating, and resistance sets your voltage drop. In low-voltage DC systems, voltage drop […]
A voltage drop calculation tells you how much voltage a wire loses between the source and the load. Lose too much and inverters shut off at low voltage, motors run hot, and chargers never finish. The math is just Ohm’s law applied to the wire, and you can do it with a calculator and one […]
AC vs DC explained in one line: direct current (DC) flows one way, and alternating current (AC) keeps reversing direction. Your solar panels and batteries make DC. Your outlets deliver AC. Every off-grid or backup system exists to move power between the two, and knowing the difference makes inverters, chargers and wiring much easier to […]
Amp-hours vs watt-hours comes up every time someone compares a 12V battery to a 48V battery or to a portable power station. The short version: watt-hours tell you how much energy a battery holds. Amp-hours only mean something once you know the voltage. Here’s how to convert between them and compare batteries fairly. Amp-Hours vs […]
A watts to amps calculator comes down to one line, amps = watts ÷ volts, the same relationship the U.S. Department of Energy uses for appliance energy estimates. This guide gives the formula, a ready-made chart for common voltages, and the two corrections people forget: inverter losses and power factor. Use it to size wire, […]
The Ohm’s law formula is V = I × R: voltage equals current times resistance, the relationship physicist Georg Ohm published in 1827. It’s the most useful equation in DIY electrical work. It explains why cables get hot, why voltage sags under load, and why a dead short on a battery is so dangerous. Here’s […]
