12V Electric Blankets & Heated Bedding for Campervans: Complete Guide
An electric blanket is one of the most efficient ways to stay warm in a campervan. Running the diesel heater all night keeps the whole van warm — including the empty air above your bed. An electric blanket heats only the space you occupy (your bed), using a fraction of the power.
I switched to a 12V electric blanket two winters ago. My diesel heater now runs for 20 minutes before bed and 10 minutes in the morning. The blanket keeps me warm through the night on 15–30W. My battery thanks me.
12V vs 240V Electric Blankets
| Feature | 12V Blanket | 240V Blanket (via inverter) |
|---|---|---|
| Power draw | 30–60W | 60–150W |
| Battery drain (8h) | 20–40Ah | 40–100Ah |
| Inverter needed | No | Yes (adds 10% loss) |
| Warm-up time | 15–30 minutes | 5–10 minutes |
| Cost | £30–60 | £20–40 (blanket) + inverter cost |
| Safety (low voltage) | High | Low (mains voltage in bed) |
Which is best? A 12V blanket is the right choice for off-grid van life. It uses half the power of a 240V blanket (no inverter losses) and is safer (12V vs 240V in your bed). The only advantage of a 240V blanket is faster warm-up.
Power Consumption
| Blanket Setting | 12V Draw | 8-Hour Battery Cost (100Ah battery) |
|---|---|---|
| Low (1) | 30W (2.5A) | 20Ah (20% of battery) |
| Medium (2–3) | 45W (3.8A) | 30Ah (30%) |
| High (4–5) | 60W (5A) | 40Ah (40%) |
| Pre-heat only (30 min on high) | 60W × 0.5h = 30Wh | 2.5Ah (2.5%) |
Recommendation: Run the blanket on high for 20–30 minutes before bed (pre-heat), then switch to low for the night. This uses 10–15Ah total — manageable for any 100Ah+ battery.
Blanket Types
| Type | Coverage | Cost | Best For |
|---|---|---|---|
| Under-sheet (fitted) | Full mattress | £35–55 | Permanent install, best heat distribution |
| Throw (over-blanket) | Single person lap | £25–40 | Flexible, can move around the van |
| Mattress pad | Full mattress, thicker | £40–60 | Extra warmth, best for winter |
| Heated sleeping bag liner | Sleeping bag | £20–35 | Wild camping, tent, extreme cold |
Best for campervans: The under-sheet (fitted) blanket. It sits between your mattress and bottom sheet, covers the full bed, and does not move around. The heat rises through the mattress — warm and comfortable.
12V vs Battery-Powered vs USB
| Power Source | Pros | Cons |
|---|---|---|
| 12V (cigarette plug or hardwire) | Direct to battery, no battery pack to charge | Requires 12V cable run |
| USB (5V) | Can use power bank | Very low power (5–10W) — barely warms |
| Battery pack (rechargeable) | Portable, no wiring | Limited runtime (4–6 hours), battery wears out |
| 12V with timer | Auto-off saves battery | More expensive |
Best option: Hardwired 12V with a timer. Wire it to a 12V circuit with a 5A fuse. Most 12V blankets include a 4-hour or 8-hour auto-off timer.
Installation
Hardwiring a 12V Blanket
- Remove the cigarette plug (if the blanket comes with one). The plug is a poor connection for a permanent install.
- Splice the positive wire into a 12V circuit that is switched or permanent, depending on your preference.
- Switched (ignition): Blanket only works when the engine is on. Not ideal.
- Permanent leisure circuit: Blanket works when the battery has power. Best for van life.
- Install a 5A inline fuse on the positive wire.
- Route the negative wire to the negative busbar or a chassis ground point.
- Hide the controller in a bedside pocket or mount it to the bed frame.
Cable requirements: The blanket draws 5A max. 1.5mm² cable is sufficient.
Connectors
If you want the blanket to be removable (for washing or summer storage), use:
| Connector | Cost | Best For |
|---|---|---|
| 2-pin waterproof connector | £5–8 | Permanent install + removable blanket |
| Anderson PowerPole | £3–5 | Modular system |
| Cigarette plug (original) | £0 | Simplest — just use the existing plug |
| Screw terminal block | £1–2 | Secure hardwired connection |
Safety
| Risk | Prevention |
|---|---|
| Overheating | Only use blankets with automatic overheat protection (all reputable brands have this) |
| Fire | Do not fold or bunch the blanket — it can overheat if the wires are bunched |
| Water | Do not use a wet blanket. If the mattress gets damp from condensation, dry it before using the blanket. |
| Battery drain | Use the timer function. An 8-hour timer prevents the blanket from running all day and draining the battery. |
| Low voltage | At 12V, even a short circuit is relatively safe. Still fuse the circuit. |
Battery Impact
A 12V electric blanket on low setting for 8 hours uses 20Ah. On a 200Ah LiFePO4 battery, that is 10% of usable capacity. On a 100Ah battery, it is 20%.
| Battery Bank | 8-Hour Cost (Low Setting) | 8-Hour Cost (High Setting) |
|---|---|---|
| 100Ah | 20% | 40% |
| 200Ah | 10% | 20% |
| 300Ah | 7% | 13% |
| 400Ah | 5% | 10% |
Diesel heater comparison: A diesel heater running all night (50% duty cycle) uses 120–150Wh (10–12Ah) — about half the power of a 12V blanket. However, the blanket is silent (no diesel heater fan) and does not create condensation (diesel heaters dry the air, which is good, but the fan noise can be annoying).
The ideal strategy: Run the diesel heater for 20 minutes before bed (warms the van to 18–20°C), switch to the electric blanket for the night, run the diesel heater for 10 minutes in the morning.
Best 12V Electric Blankets for UK Campervans
| Brand | Type | Power | Timer | Price | Best For |
|---|---|---|---|---|---|
| Snug Rug | Under-sheet | 50W | 8h | £45 | Excellent value, UK brand |
| VanWarm | Under-sheet | 55W | 4h/8h | £50 | Designed for vans |
| RoadPro | Throw | 45W | 4h | £35 | Portable, move around |
| Cozywoggle | Mattress pad | 60W | 8h | £55 | Thicker, warmer |
| Generic 12V (Amazon) | Under-sheet | 40–60W | 4h/8h | £25–35 | Budget option |
My recommendation: The Snug Rug 12V under-sheet blanket (£45) or the VanWarm mattress pad (£50). Both are designed for van life, have proper safety certifications, and include timers.
FAQ
Q: Will a 12V electric blanket drain my battery overnight? A: On low setting (30W), it draws 20Ah over 8 hours. On a 200Ah LiFePO4 battery, that is 10% — fine. On a 100Ah lead-acid battery (50% usable), that is 40% — noticeable but manageable if you have solar or drive the next day.
Q: Can I use a 12V blanket with a solar-only system? A: Yes, if your solar system is sized for winter. In December, a 400W system produces 240Wh/day. An electric blanket on low for 8 hours uses 240Wh. That leaves no power for anything else. Use the blanket sparingly or run the diesel heater on cold nights to preserve battery.
Q: Is a 12V blanket safe to sleep on? A: Yes, if it has overheat protection and you follow the manufacturer's instructions. Do not use a damaged blanket (frayed wires, exposed elements). Do not fold or bunch the blanket.
Q: Can I wash a 12V electric blanket? A: Check the manufacturer's instructions. Most 12V blankets have a detachable controller and can be machine-washed on a gentle cycle. Never submerge the controller or the plug.
Q: Will a 12V blanket work with a campervan diesel heater? A: Yes — the two complement each other. Use the diesel heater for the initial warm-up and morning warm-up, and the electric blanket to stay warm overnight while the heater is off. This combination halves your winter heating power consumption.
Q: What size 12V blanket do I need? A: Measure your mattress. Standard UK single (90 × 190cm), double (135 × 190cm), or the custom mattress sizes common in van conversions. Most 12V blankets come in single and double sizes — choose the closest match to your mattress.
