Sizing depends on what you're running. Light loads (LED lights, phone charging, USB): 80-120W panel. Fridge + lights + small loads: 150-200W minimum. Fridge + lights + induction or kettle: 300W+ with a large battery. Permanent setup on a caravan/camper: 200-400W rooftop is the sweet spot. Folding portable panels are flexible — set up in sun while you camp in shade. Always pair with a quality MPPT regulator (Victron, Renogy, Redarc) for 30% better efficiency than basic PWM units.

PWM (Pulse Width Modulation) regulators are simple and cheap but inefficient — they essentially throttle solar panel voltage to match battery voltage, wasting any excess. MPPT (Maximum Power Point Tracking) regulators convert excess voltage into amperage, extracting 25-30% more energy from the same panels. For any system over 100W, MPPT is the no-brainer choice. Quality brands: Victron, Redarc, Renogy. Budget $150-400 for a 30A MPPT regulator that handles up to 400W of panels.

AGM (Absorbent Glass Mat) batteries are the established option — affordable ($300-400 for 100Ah), reliable, but heavy (~30kg) and limited to 50% usable depth-of-discharge (so 100Ah AGM = 50Ah real). Lithium iron phosphate (LiFePO4) is the modern choice — usable to 80-90% DoD (100Ah lithium = 85Ah real), 1/3 the weight (~12kg), 4-8x the cycle life. Initial cost is 2-3x AGM ($800-1,500 for 100Ah) but lifetime value is far better. For frequent campers, lithium pays back within 2-3 years.

A DC-DC charger takes 12V from your vehicle alternator and converts it to a properly regulated multi-stage charge (bulk/absorption/float) for your auxiliary battery. Why you need one: modern smart alternators (most cars after 2015) reduce voltage to save fuel — without a DC-DC charger your auxiliary battery never reaches full charge. Also charges at higher amperage (25-50A) than a basic isolator. Quality brands: Redarc, Renogy, Victron. Budget $400-800 for a quality 25-50A unit. Can also include MPPT solar input.

Match inverter size to your largest single load. Small inverters (300-600W) handle laptops, lights, small appliances. Mid-size inverters (1000-1500W) handle TVs, induction cooktops, hair dryers, kettles (briefly). Large inverters (2000W+) needed for microwaves, air conditioners, power tools. Pure sine wave inverters are essential for anything with electronics (TVs, laptops, CPAP machines); modified sine wave is cheaper but causes problems. Battery capacity must match — a 2000W inverter at full load draws 200A from a 12V battery, depleting 100Ah in 30 minutes.

Inverter: converts stored battery DC power to AC power — silent, instant, fuel-free, but limited by battery capacity and recharge time. Generator: burns petrol or diesel to produce AC power directly — unlimited runtime (with fuel), but noisy, smelly, and requires fuel storage. Inverter generator (Honda EU2200i, Yamaha EF2400iS) combines a small petrol engine with electronic inverter output — quiet, fuel-efficient, clean power for sensitive electronics. For camping, an inverter + solar is generally better than a generator. For high-load needs (air conditioning), a quality inverter generator is the practical choice.

Use correctly sized cable — 12V systems suffer voltage drop over distance; oversized cable is always safer than undersized. As a guide: 6mm² for 30A circuits up to 3m, 8mm² for runs over 3m. Always fuse circuits at the battery (within 30cm) — fuse value should match cable rating, not load. Use Anderson plugs for high-current connections (50A or 175A); cigarette plugs only for low-current accessories. Crimp and heat-shrink all terminals; never use unprotected lug-and-screw connections in a vehicle environment. Get a 12V auto electrician to do major installs.

A genderless high-current connector — same plug on both ends, rated for 50A (small grey) or 175A (large grey/red). Used for connecting solar panels to regulators, charging auxiliary batteries from a tow vehicle, and any high-current 12V connection that needs to be unplugged regularly. Always use the correct size for your current load (50A handles up to 600W of solar; 175A handles inverter loads or DC-DC charging). Crimp and heat-shrink the terminals properly — bad crimps melt and start fires. Mount with a weatherproof cover for permanent installs.

A typical 12V camping fridge draws 1-2A when running, with a duty cycle of 30-50% depending on temperature and contents. Daily consumption: 15-30Ah per 24 hours. From a 100Ah AGM (50Ah usable): 1.5-3 days without recharging. From a 100Ah lithium (85Ah usable): 3-5 days. With 200W of solar, you can run a fridge indefinitely in good sun. Tips to extend battery life: insulate the fridge, keep it in shade, set to 4°C (not 1-2°C), and don't open it constantly.

Match capacity to vehicle: 1000-2000 peak amps jumps petrol cars up to V6; 2000-3000 peak amps jumps V8 and small diesel; 3000+ amps jumps large diesel utes and trucks. Lithium jump starters (NOCO, Schumacher, Projecta) are now the standard — pocket-sized, 12V output, USB ports, often with built-in air compressor and emergency LED light. Charge to full before storage and recharge every 6 months. Far better than jumper cables for solo travel.

For tent and awning lighting: 12V LED strip lights (Hardkorr, Korr) at 800-1500 lumens give wide soft light. For specific tasks: USB-rechargeable lanterns (Goal Zero, Black Diamond) are versatile. For outdoor area lighting: 12V flood/spot LEDs from Hardkorr or Stedi. Use warm-white (3000K) bulbs for camp ambience; cool-white (5000K) is harsh outdoors. Always have multiple lighting sources — area lights, head torch, hand torch — so you're never caught out. Quality LEDs draw 0.1-0.5A — negligible battery impact.

A battery monitor (Victron BMV-712, Redarc BMS, Renogy 500A) measures actual amp-hours in/out and gives you a real percentage of state-of-charge — far more accurate than a voltmeter. Voltage alone is misleading: a battery sitting at 12.6V might be 100% charged or 50% charged depending on rest time. Quality monitors run $200-400 and pay for themselves by preventing battery damage from over-discharge. Lithium batteries with built-in BMS show state-of-charge via Bluetooth apps — simpler but less detailed.

Yes, with caveats. Inverter generators (Honda EU2200i, Yamaha EF2400iS) produce clean AC power suitable for caravan electronics, fridges, and air conditioners. Sizing: 2.0-2.4kVA handles a single AC; 3-4kVA handles AC + microwave + chargers. Plug into the caravan's 240V inlet as you would a powered site. Conventional (non-inverter) generators produce dirty power that can damage sensitive electronics — avoid for caravan use. Many free-camp sites have generator-use rules (typically 8am-5pm, max noise levels) — check before running.

A BMS is the smart electronics in modern lithium batteries that protect against: over-discharge (under-voltage cutoff), over-charge (over-voltage cutoff), short-circuit, over-temperature, and cell imbalance. Built-in BMS is standard on quality LiFePO4 batteries (BB, Enerdrive, Power-Sonic, Renogy). External BMS units (Redarc Manager) integrate solar, DC-DC, and battery management in a single device with a remote display. The BMS is what makes lithium safer and longer-lasting than AGM — never buy a lithium battery without a quality BMS.

Calculate daily power consumption first: list every load (fridge 15-30Ah, lights 5Ah, USB charging 5Ah, water pump 2Ah, inverter loads X Ah). Add 20% buffer. Battery capacity: aim for 3 days of autonomy without solar input (so daily consumption × 3, divided by usable depth of discharge). Solar: divide daily consumption by 4 hours of "good sun" — that's your minimum panel wattage. Always oversize: real-world conditions (clouds, shade, dust) reduce solar output by 30-50%. Get a 12V specialist (Redarc, Enerdrive dealers) to design and install for serious setups.