2026-04-15 · ChargeWizards

Can My Panel Handle an EV Charger?

Short answer: almost certainly yes. The longer answer involves three things every Bay Area homeowner should understand — your panel's amperage rating, the NEC 220.87 load calculation, and Dynamic Power Management. We've installed Level 2 chargers on hundreds of Peninsula and South Bay panels; fewer than 1 in 5 actually needed an upgrade. The other four were sold an upgrade by another contractor who didn't want to do the engineering.

1. Find your panel rating

Open your main breaker panel and look at the largest breaker — usually at the top. If it says 100, you have a 100A panel. If it says 200, you have 200A. San Francisco Victorians often have 60A or even 30A service. Most Peninsula homes built since 1980 are 200A.

A few important footnotes. If you have a sub-panel (a smaller panel fed from a larger main), the breaker that feeds that sub-panel is what matters for the EV circuit, not the main. If your main breaker reads 200A but your sub-panel feeder is 60A, you've got a 60A pool to draw from at the garage. We always trace the actual feed before quoting. And if you genuinely don't know — Federal Pacific stab-lok panels were installed in many Bay Area homes through the late 1980s and have a known fire-safety issue regardless of EV plans. Those need a real assessment, not a guess.

2. Understand NEC 220.87

The National Electrical Code (NEC) section 220.87 lets electricians calculate your panel's actual peak load by reading 30 days of utility data and adding 25% margin. If the highest 15-minute interval in those 30 days, plus the new EV load, plus 25% safety, comes in under your panel's rating — you're fine. No upgrade needed.

A typical 100A home uses peaks of 40–60A even on hot summer days. That leaves real headroom for an EV charger. Where do those peaks come from? Usually a single window AC starting up while the dryer is running and the oven is preheating. Most of the day, even a busy household is pulling 15–25A continuously. PG&E's SmartMeter data captures this in 15-minute intervals — Palo Alto Utilities, Silicon Valley Power, and CleanPowerSF all expose the same data through their customer portals. Pull a 30-day CSV, find the peak, add 25%, add the EV charger's 80% continuous load (a 48A charger = 38.4A continuous), compare to your panel rating. Sub-panel? Same math against the sub-feed.

California amended Title 24 in 2019 to require new construction to be EV-ready, but the vast majority of Bay Area housing predates that. NEC 220.87 is what makes those existing homes work. The City of San Mateo, City of Burlingame, City of Palo Alto, and City of Redwood City building departments all accept 220.87 calculations on first submission — provided the calc is complete, with the utility data attached and signed by a licensed contractor. Incomplete submissions are the #1 reason permit reviews bounce back.

3. How DPM closes the gap

Dynamic Power Management (DPM) puts a CT sensor on your main service conductors. The EV charger reads the signal 100 times per second and reduces its draw automatically when the rest of the house ramps up — making even tight panels work safely.

DPM is fully NEC 625-compliant. It's the reason ChargeWizards rarely quotes a panel upgrade. Most electricians will quote the upgrade by default — saves them the engineering work, costs you $2,500–$5,000.

DPM hardware costs around $550 in our pricing. That's a one-time line item that replaces a $2,500–$5,000 panel upgrade. The math wins almost every time — and unlike a panel upgrade, DPM doesn't require PG&E service shutoff, doesn't need a service-equipment inspection, and doesn't add weeks to the project timeline. A typical DPM-equipped install in San Mateo, Foster City, or Burlingame is one day, one permit, no PG&E coordination required.

When you DO need an upgrade

• Federal Pacific or Zinsco panels (safety hazard regardless of EV plans)
• Panels that are physically full with no breaker slots
• Real peak loads (per the 220.87 calc) close to your panel's rating
• Plans for solar + battery + EV + heat pump on the same panel
• 60A or smaller services (common in older San Francisco Victorians and some Atherton estates with original wiring)

For these cases the upgrade is the right call — and we'll tell you that honestly. ChargeWizards subcontracts the actual service swap to a panel-upgrade specialist when needed; we don't mark up that work, and we don't recommend it unless the load calc forces it.

What ChargeWizards charges in the Bay Area

Real numbers, no "starting at" tricks. Base Level 2 install (200A panel, 10–20 ft run, simple wall mount) runs $1,600–$2,000 including the permit. Add $550 if you need DPM. Add $595 if you specifically want the Tesla Wall Connector hardware supplied by us. Add $750–$950 for the city permit fee, depending on the jurisdiction. A typical 100A San Mateo home with DPM and a Tesla Wall Connector lands around $2,800–$3,200 all-in. Compare that to $5,500–$7,000 from contractors who insist on the panel upgrade — and you can see why we built the company around DPM.

If you're unsure, send us photos of your panel and a screenshot of your last 30 days of PG&E (or Palo Alto Utilities, or Silicon Valley Power, or CleanPowerSF) usage data. We'll do the load calc free and tell you honestly whether you need an upgrade. Most homeowners who think they need the upgrade don't — and the ones who do, deserve to know that too.

FAQ

More on this: How DPM lets you install an EV charger without a panel upgrade · Full DPM guide · What it actually costs.