This is every component you need for a complete van electrical system, what each one does, and typical prices. Use it as a shopping list and sanity check.
Core 12V system components
Battery
What it does: Stores energy for use when solar isn't producing and the engine isn't running.
What to buy: LiFePO4 (lithium iron phosphate) for van builds — 2× the usable capacity of AGM at similar weight.
| Size | Use case | Approx price |
|---|---|---|
| 100Ah LiFePO4 | Weekend builds | $250–$350 |
| 200Ah LiFePO4 | Full-time, moderate loads | $400–$600 |
| 300Ah LiFePO4 | Full-time, heavy loads | $600–$900 |
Brands: Battle Born, LiTime (Ampere Time), SOK, Renogy, Chins.
Solar panels
What they do: Convert sunlight to DC electricity to charge the battery.
| Size | Use case | Approx price |
|---|---|---|
| 200W (2× 100W) | Weekend builds, low loads | $100–$160 |
| 300W | Full-time moderate use | $150–$220 |
| 400W | Full-time heavy use | $200–$300 |
Brands: Renogy, Rich Solar, HQST.
MPPT solar charge controller
What it does: Regulates power from panels into the battery — protects against overcharge, maximizes harvest.
| Rating | For panels | Approx price |
|---|---|---|
| 20A MPPT | Up to 260W (12V battery) | $40–$80 |
| 30A MPPT | Up to 390W | $60–$100 |
| 40A MPPT | Up to 520W | $80–$150 |
Brands: Victron SmartSolar (best), Renogy Wanderer/Rover, EPever.
DC-DC charger
What it does: Charges house battery from the vehicle alternator while driving, with a proper charge profile.
| Rating | Charge rate | Approx price |
|---|---|---|
| 20A DC-DC | 240W | $80–$120 |
| 30A DC-DC | 360W | $130–$200 |
| 40A DC-DC | 480W | $200–$350 |
Brands: Renogy DCC series, Victron Orion XS, Votronic.
Inverter (for 120V AC loads)
What it does: Converts 12V DC battery power to 120V AC for outlets and appliances.
| Size | For loads | Approx price |
|---|---|---|
| 1,000W | Laptop, small appliances | $100–$150 |
| 2,000W | Induction cooking, coffee maker | $180–$250 |
| 3,000W | Air compressor, large loads | $300–$450 |
Brands: Renogy, AIMS, Victron (MultiPlus for inverter/charger combo).
Distribution and protection
Main fuse/breaker
What it does: Protects the battery cable from the battery to the bus bar. Must be within 18 inches of the battery positive terminal.
- ANL fuse holder + fuse: 200–300A, ~$15–$30
- Bus bar with integrated circuit breaker: ~$40–$80
Positive bus bar
What it does: Central distribution point for all positive connections from the battery.
- Blue Sea Systems 250A bus bar: ~$20–$30
- Lynx Distributor (Victron, combines bus bar + fuses): ~$80
Negative bus bar / ground block
What it does: Central return point for all negative connections.
- Blue Sea Systems ground block: ~$15–$25
Fuse block (for 12V loads)
What it does: Individual fused circuits for each 12V load — fridge, lighting, fans, USB hubs.
- 6-circuit fuse block with bus: ~$20
- 12-circuit fuse block: ~$30–$50
- Blue Sea 5025e PowerBar (integrated): ~$60
Battery monitor / shunt
What it does: Measures actual amp-hours in and out to give accurate state-of-charge. Essential for LiFePO4.
- Victron SmartShunt 500A + BMV-712 display: ~$100–$130
- Renogy 500A shunt + monitor: ~$60
Wiring and connectors
| Item | Typical need | Price |
|---|---|---|
| 2/0 AWG cable (battery to inverter) | 4–6 feet | $3–$5/ft |
| 4 AWG cable (DC-DC, MPPT to battery) | 6–10 feet | $1–$2/ft |
| 10 AWG wire (load circuits) | 20–30 feet | $0.30–$0.60/ft |
| ANL fuse + holder | 1× | $15–$25 |
| Inline blade fuses | Assortment | $10–$20 |
| Lugs and terminals | Assortment | $15–$30 |
| Heat shrink butt connectors | Pack | $10–$20 |
Totals by build tier
| Tier | Battery | Solar | Other | Total parts |
|---|---|---|---|---|
| Weekend 100Ah | $300 | $120 | $300 | ~$720 |
| Full-time 200Ah | $500 | $200 | $600 | ~$1,300 |
| Full-time 200Ah + inverter | $500 | $200 | $900 | ~$1,600 |
Related
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Roam Wired turns campervan research into practical plans. We publish transparent guidance, a free electrical design tool and marketplace resources for UK and US van builders.
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