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.
The quickest way to turn this into a plan is our free electrical calculator: add your appliances and it sizes the battery, solar, charging and inverter, then produces a wiring diagram and parts list.
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).
US equipment options
Build the shopping list around the design
These are examples for two different system roles. Keep essential, conditional and optional components separate, and verify every exact variant before ordering.
House battery
Epoch 12V 105Ah Essential Series LiFePO4 Battery (1.34kWh)
A compact-capacity option to compare for a modest daily energy budget.
Check before choosing: Physical fit, usable energy, discharge current and the exact cold-charge/heating specification.
Alternator charging
Victron Orion XS 12/12-50A DC-DC Battery Charger
A 12V-to-12V charging option for a compatible vehicle and house-battery installation.
Check before choosing: Alternator headroom, cable run, battery charge acceptance and the required controls/protection.
These links open our US shop. Check the exact configuration, current price and availability there; affiliate products are purchased from the named supplier. We may earn a commission from qualifying purchases.
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 |
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Jack Kennedy is a self-builder who has built two vans. He created Roam Wired to simplify conversion planning and share free tools, supported by affiliate links.
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