Running Power Tools from a Van Inverter: What Size Do You Need?
Power tools have some of the highest surge demands of any load you'd run from an inverter. Planning this correctly avoids a frustrating experience of tools that won't start or inverters that shut down.
Why power tools are demanding
Electric motors draw 2–5× their running wattage at startup for a fraction of a second. This surge lasts only 10–50 milliseconds but must be within the inverter's surge rating.
A circular saw rated at 1,800W running may surge to 5,400W at startup. Your inverter needs a surge rating above 5,400W or it will fault at startup.
Running watts vs. surge watts:
| Tool | Running watts | Startup surge | Min inverter surge rating |
|---|---|---|---|
| Cordless drill (corded) | 500–700W | 1,500–2,000W | 2,000W surge |
| Jigsaw | 500–1,000W | 2,000–3,000W | 3,000W surge |
| Circular saw | 1,200–2,200W | 3,500–6,000W | 5,000W+ surge |
| Angle grinder (4.5") | 800–1,400W | 2,500–4,000W | 3,500W surge |
| Angle grinder (7") | 1,500–2,400W | 4,500–7,000W | 6,000W+ surge |
| Air compressor (1–2 HP) | 1,000–1,500W | 3,000–5,000W | 4,000W+ surge |
| Random orbital sander | 300–600W | 900–1,800W | 2,000W surge |
| Reciprocating saw | 1,000–1,400W | 3,000–4,000W | 3,500W surge |
Recommended inverter sizes for power tools
For light duty (drill, sander, jigsaw): 2,000W inverter with 4,000W surge rating. Most 2,000W pure sine inverters have adequate surge capacity for these tools.
For medium duty (circular saw, angle grinder, router): 3,000W inverter with 6,000W+ surge rating. Check the spec sheet — not all 3,000W inverters have 6,000W surge capability.
For heavy duty (large angle grinder, air compressor, table saw): 5,000W+ or a dedicated generator. A generator is often more practical for heavy tool use than batteries.
Battery considerations
A circular saw drawing 1,800W at 12V through an inverter pulls ~165A. Most 100Ah LiFePO4 batteries support 100A continuous discharge — one battery isn't enough. A 200Ah bank handles it comfortably.
For occasional short cuts, battery discharge is not the limitation — startup surge handling and inverter surge rating are.
Do you actually need corded tools?
Modern cordless tool platforms (DeWalt FlexVolt, Milwaukee M18 Fuel, Makita XGT) match or exceed corded performance for most tasks. Running a battery-powered circular saw from the tool's own 18V–60V battery eliminates the inverter surge challenge entirely. Many van lifers carry a good cordless tool set and skip the corded-tool-on-inverter scenario.
If you need high-powered tools frequently (e.g., you're a contractor using the van as a work vehicle), a generator is more practical than a battery inverter system for that purpose.