Can I use household wire (Romex/NM-B/VD) in a camper van?

No. Household wire is solid core and will break from vibrations while driving. Always use stranded (fine-strand) automotive wire such as FLRY-B or GXL. These are designed for vehicles and have the right insulation for an environment with vibration, temperature changes and moisture.

Do I need to fuse every single cable in my camper van?

Every cable connected to the positive terminal of the battery (directly or indirectly) needs a fuse. The fuse protects the cable from overheating in case of a short circuit. Place fuses as close to the battery as possible, ideally within 30 cm. Cables between a fuse and a device are already protected by that fuse.

What is the difference between a blade fuse, ANL fuse and class T fuse?

Blade fuses (ATO/ATC) are used for low-current circuits up to about 30A and fit in standard automotive fuse boxes. ANL and MIDI fuses handle 40-300A and are used for heavier circuits like DC-DC chargers and small inverters. Class T fuses are for very high-current circuits (up to 400A+) with high interrupt capacity, used for main battery protection and large inverters.

How do I convert between mm² and AWG?

There is no exact 1:1 conversion because mm² measures cross-sectional area while AWG is a gauge number (lower = thicker). The most common equivalents: 0.75mm² = 18 AWG, 1.5mm² = 16 AWG, 2.5mm² = 14 AWG, 4mm² = 12 AWG, 6mm² = 10 AWG, 10mm² = 8 AWG, 16mm² = 6 AWG, 25mm² = 4 AWG, 35mm² = 2 AWG, 50mm² = 1/0 AWG, 70mm² = 2/0 AWG.

Is this cheatsheet also valid for 24V systems?

The wire gauges, fuse principles and power consumption values are the same. The main difference: at 24V, the current is halved for the same wattage, so you can use thinner cables or cover longer distances. Battery capacity in Ah is also halved for the same energy (Wh). Solar yield in Ah is halved but Wh stays the same.

Camper van electrical cheatsheet: all values at a glance

Everything you need for your camper van electrical installation in one page. Wire gauges, fuse sizes, typical power consumption, battery capacity and solar yield. Bookmark this page or print it out and hang it in your workshop.

Calculate your own values

Cable calculator →Fuse calculator →Battery bank calculator →Solar panel calculator →Power consumption monitor →Inverter calculator →

Wire gauge: mm² to AWG and maximum current

A cable that is too thin causes heat build-up and fire hazard. Too thick wastes money and is harder to route. This table shows the maximum continuous current per cable size, so you can choose the thinnest cable that is still safe for your circuit.

mm²	AWG	Max current	Typical use
0.75 mm²	18 AWG	10A	LED lighting, short signal cables
1.0 mm²	17 AWG	13A	Lighting, switches
1.5 mm²	16 AWG	16A	Lighting circuits, USB chargers
2.5 mm²	14 AWG	22A	Fridge, water pump, fans
4.0 mm²	12 AWG	30A	Heater, larger consumers
6.0 mm²	10 AWG	40A	High-power circuits
10 mm²	8 AWG	55A	Sub-distribution, small inverter
16 mm²	6 AWG	75A	Main battery cables, medium inverter
25 mm²	4 AWG	100A	Inverter up to 1500W, alternator charging
35 mm²	2 AWG	130A	Inverter up to 2000W
50 mm²	1/0 AWG	170A	Large inverter, main battery connection
70 mm²	2/0 AWG	215A	High-power systems

When in doubt, go one size up. Current ratings vary by insulation type, temperature and installation method.

Fuse sizes: which fuse for which circuit

The fuse protects the cable, not the device. Without the right fuse, a short circuit can overheat a cable before you notice it. Always choose based on the cable's maximum current rating and place fuses within 30 cm of the battery.

Blade fuses (ATO/ATC) — up to 30A

Rating	Circuit
3A	LED strip (single color)
5A	Interior lighting, USB charger
7.5A	Reading lights, small fan
10A	Water pump, diesel heater, vent fan
15A	Compressor fridge, multiple fans
20A	Large fan, 12V outlet
25A	Heavy consumer, sub-panel feed
30A	Shore power charger

ANL / MIDI / MEGA / Class T — 40A+

Rating	Type	Circuit
40A	ANL/MIDI	DC-DC charger, MPPT controller
60A	ANL/MIDI	Sub-distribution panel feed
80–100A	ANL/MIDI	Small inverter (up to 1000W)
150A	ANL/MEGA	Medium inverter (1000–1500W)
200A	ANL/MEGA	Large inverter (1500–2000W)
250–300A	Class T	Main battery fuse, large inverter (2000W+)

Power consumption: typical values at 12V

You need to know how much power your devices draw before you can size your battery, solar panels and cables. These are typical values — always check your specific device's datasheet for the exact figure.

Lighting

LED strip (per m)5–15W0.4–1.3A

LED spot/puck2–5W0.2–0.4A

Reading light3–5W0.3–0.4A

Kitchen

Compressor fridge30–50W2.5–4.2A

Water pump30–60W2.5–5A

Induction hob1000–2000Wvia inverter

Climate

Roof vent/Maxx Fan10–40W0.8–3.3A

Diesel heater10–30W0.8–2.5A

Glow plug (start)80–100W7–8A

Electronics

Phone charging10–15W0.8–1.3A

Laptop charging45–65Wvia inverter

Starlink Mini25–40Wvia inverter

Other

12V TV (24")25–40W2–3.3A

Inverter standby5–20W0.4–1.7A

Alarm/GPS tracker1–5W0.1–0.4A

Battery capacity: how many Ah do you need?

Your battery must store enough energy to bridge cloudy days and nights. Undersizing leads to deep discharges that shorten battery life. Lithium (LiFePO4) gives 80–90% usable capacity, AGM/gel only 50%.

Weekend, basic

20–30 Ah/day

LiFePO450 Ah

AGM100 Ah

Weekend, comfort

50–70 Ah/day

LiFePO4100 Ah

AGM200 Ah

Full-time, minimal

60–80 Ah/day

LiFePO4200 Ah

AGM2× 120 Ah

Full-time, comfort

100–150 Ah/day

LiFePO4300 Ah

AGM—

Full-time, heavy

200+ Ah/day

LiFePO4400+ Ah

AGM—

For off-grid: plan at least 2 days autonomy without solar. Multiply daily consumption by 2.

Solar yield per region and season

Solar yield varies enormously by region and season. Sizing your panels on summer figures means you'll run short in autumn. Use the worst season you'll travel in to calculate the Wp you need.

Daily yield in Ah at 12V per 100Wp panel

Region	Summer	Spring/autumn	Winter
Southern Europe	35–45 Ah	20–30 Ah	10–20 Ah
Central Europe	25–35 Ah	12–20 Ah	4–10 Ah
Northern Europe	25–35 Ah	8–15 Ah	1–5 Ah
Southwest US	40–50 Ah	25–35 Ah	20–30 Ah
Pacific Northwest	25–35 Ah	12–20 Ah	5–10 Ah
Northeast US/Canada	25–35 Ah	15–25 Ah	8–15 Ah

Quick sizing: daily Ah ÷ yield per 100Wp (worst season) = required Wp. Example: 80 Ah ÷ 16 = 500Wp.

Voltage drop: maximum cable length

Voltage drop means your device receives less than 12V, causing malfunctions or shutdowns. Long cables and high currents make it worse. This table shows the maximum one-way cable length for 3% drop — for inverter cables aim for under 1%.

Rating	1.5 mm²	2.5 mm²	4 mm²	6 mm²	10 mm²	16 mm²	25 mm²
5A	3.0m	5.0m	8.1m	12.1m	20.2m	32.3m	50.4m
10A	1.5m	2.5m	4.0m	6.0m	10.1m	16.1m	25.2m
15A	1.0m	1.7m	2.7m	4.0m	6.7m	10.8m	16.8m
20A	0.8m	1.3m	2.0m	3.0m	5.0m	8.1m	12.6m
30A	—	0.8m	1.3m	2.0m	3.4m	5.4m	8.4m
50A	—	—	0.8m	1.2m	2.0m	3.2m	5.0m
80A	—	—	—	0.8m	1.3m	2.0m	3.2m
100A	—	—	—	—	1.0m	1.6m	2.5m

For 1% drop: divide by 3. For 24V systems: multiply by 2.

Cable color coding: standard colors

Using consistent colors prevents dangerous mix-ups. These are the most common conventions for 12V DC camper van wiring.

Color	Use
Red	Positive (+) — battery, fuse box, all 12V positive leads
Black	Negative (−) / ground — battery negative, chassis ground
Green/yellow	Earth/chassis bond — safety ground to vehicle body
Blue	Solar panel cables — from panel to charge controller
Yellow	Ignition/accessory switched — circuits that only run with ignition on

These are conventions, not law. Always label your cables and document your wiring diagram. In a camper van with multiple builders, consistent color coding prevents dangerous mistakes.

Battery types compared

Not every battery is suitable for camper van use. Cycle life, depth of discharge and weight differ enormously between types.

Type	Cycle life	Usable (DoD)	Weight/100Ah	Self-discharge/mo	Temp range
LiFePO4 (lithium)	2000–5000	80–90%	~13 kg	2–3%	-20 / +60 °C
AGM	400–800	50%	~30 kg	3–5%	-20 / +50 °C
Gel	500–1000	50%	~32 kg	2–3%	-20 / +50 °C
Flooded lead-acid	200–400	50%	~30 kg	5–15%	-20 / +50 °C

LiFePO4 is the best choice for most camper van builds: lightest, most cycles, deepest discharge. AGM is cheaper upfront but heavier and needs replacing sooner.

Charge voltages per battery type (12V)

Setting the wrong charge voltage shortens battery life or can be dangerous. These are the correct values for your charge controller or charger at 12V nominal.

Type	Bulk	Absorption	Float	Low cutoff
LiFePO4 (lithium)	14.2–14.6V	14.4–14.6V	13.4–13.6V	10.0V
AGM	14.4–14.8V	14.6–14.8V	13.2–13.4V	10.5V
Gel	14.0–14.4V	14.1–14.4V	13.2–13.5V	10.5V
Flooded lead-acid	14.4–14.8V	14.6–14.8V	13.2–13.4V	10.5V

Always check your specific battery's datasheet — values can vary between manufacturers. Charging lithium below 0°C requires a heated battery or a charger with low-temp cutoff.

Common connectors and terminal sizes

Choosing the right connector for your cable size ensures a safe, low-resistance connection. An undersized connector causes heat and can melt.

Connector	Max current	Cable range
Anderson PP50 (SB50)	50A	6–10 mm²
Anderson SB175	175A	25–50 mm²
Anderson SB350	350A	50–70 mm²
MC4 (solar)	30A	2.5–6 mm²
Ring terminal M6	—	1.5–6 mm²
Ring terminal M8	—	6–25 mm²
Ring terminal M10	—	25–70 mm²

Always use the correct crimp tool for each connector type. A bad crimp is the most common cause of high-resistance connections and electrical fires in camper vans.

Calculate your own values

Use our free calculators to get exact values for your specific camper van setup.

Cable calculator →Fuse calculator →Battery bank calculator →Solar panel calculator →Power consumption monitor →Inverter calculator →

Frequently asked questions

Can I use household wire (Romex/NM-B/VD) in a camper van?: No. Household wire is solid core and will break from vibrations while driving. Always use stranded (fine-strand) automotive wire such as FLRY-B or GXL. These are designed for vehicles and have the right insulation for an environment with vibration, temperature changes and moisture.
Do I need to fuse every single cable in my camper van?: Every cable connected to the positive terminal of the battery (directly or indirectly) needs a fuse. The fuse protects the cable from overheating in case of a short circuit. Place fuses as close to the battery as possible, ideally within 30 cm. Cables between a fuse and a device are already protected by that fuse.
What is the difference between a blade fuse, ANL fuse and class T fuse?: Blade fuses (ATO/ATC) are used for low-current circuits up to about 30A and fit in standard automotive fuse boxes. ANL and MIDI fuses handle 40-300A and are used for heavier circuits like DC-DC chargers and small inverters. Class T fuses are for very high-current circuits (up to 400A+) with high interrupt capacity, used for main battery protection and large inverters.
How do I convert between mm² and AWG?: There is no exact 1:1 conversion because mm² measures cross-sectional area while AWG is a gauge number (lower = thicker). The most common equivalents: 0.75mm² = 18 AWG, 1.5mm² = 16 AWG, 2.5mm² = 14 AWG, 4mm² = 12 AWG, 6mm² = 10 AWG, 10mm² = 8 AWG, 16mm² = 6 AWG, 25mm² = 4 AWG, 35mm² = 2 AWG, 50mm² = 1/0 AWG, 70mm² = 2/0 AWG.
Is this cheatsheet also valid for 24V systems?: The wire gauges, fuse principles and power consumption values are the same. The main difference: at 24V, the current is halved for the same wattage, so you can use thinner cables or cover longer distances. Battery capacity in Ah is also halved for the same energy (Wh). Solar yield in Ah is halved but Wh stays the same.