Electric Vehicle Solar Panel & Battery Sizing Calculator
Adding an Electric Vehicle increases average household electricity demand by 3,500 to 6,800 kWh per year. Calculate the exact solar kW, number of 440W panels, and overnight LFP storage buffer needed to drive on 100% rooftop sunshine.
1. Select Your EV & Daily Commute
⚡ Engineering Tip: Why Charging an EV from a Home Battery Beats Direct Grid TOU
If your car is parked at work from 9 AM to 5 PM, your rooftop solar panels export power at midday for pennies (3–5¢/kWh under Net Billing) and you end up buying back expensive utility power at night. Pairing an EG4 18kPV / GridBOSS or EcoFlow Delta Pro Ultra lets you bank midday solar or use bidirectional solar-only EV charging.
Level 2 EV Charger & Solar Integration Blueprint
⚡ CHARGER EFFICIENCY🔌 Why Level 2 Charging Has a 12% AC-to-DC Conversion LossAlways size your solar array 12% larger than your EV dashboard's kWh/mile screen.
Your EV's in-dash energy screen only counts energy reaching/leaving the high-voltage DC battery pack. When charging from a 240V Level 2 wall connector (40A–48A), the vehicle's onboard AC-to-DC rectifier, battery thermal management pumps, and 240V branch wiring consume an extra 10% to 12% of electricity. Our calculator automatically includes this 1.12x real-world charging multiplier.
🛠️ NEC WIRING RULE🔋 How Smart Load Shedding Prevents a 48A EV Charger from Draining Your Home BatteryWiring your Level 2 EV charger onto the non-backed-up main panel or smart relay port.
A 48A Level 2 EV charger pulls 11.5 kW continuously—which can empty a 13.5 kWh home battery in 70 minutes during a blackout! When wiring a whole-home backup inverter (like the EG4 GridBOSS, Sol-Ark 15K, or FranklinWH aGate), land the 60A EV charger breaker on a dedicated Smart Load Port so the EV charger automatically pauses the millisecond the utility grid goes down.
Skip the $14,000 Installer Markup: Direct-Purchase Hardware & Vetted Quotes
Turnkey solar salespeople routinely charge $3.60–$4.80/W by bundling 30% loan dealer fees and $12,000+ battery margins. Buying Tier-1 UL9540 hardware directly—either DIY or hiring a local licensed electrician ($1,500–$2,500)—cuts total cost by 50–65%.
EG4 18kPV Inverter + 14.3kWh PowerPro WallMount
The gold-standard UL9540 all-in-one hybrid system. Pair an 18kW PV input hybrid inverter (200A pass-through) with an indoor/outdoor IP65 14.3kWh LiFePO4 WallMount battery—saving $12,000+ vs turnkey quotes.
- 18kW PV Input / 12kW Continuous AC Output (200A Pass-Through)
- 14.3kWh LiFePO4 (8,000+ cycles @ 80% DoD)
- UL9540 & UL1741-SB Certified for Permit Approval
EcoFlow Delta Pro Ultra (6kWh–30kWh Modular)
Skip the $30,000 contractor quote and 6-month utility interconnection wait. Delivers 7.2kW–21.6kW continuous 120V/240V split-phase output and 5.6kW Solar Input right out of the box—expandable up to 90kWh.
- 7,200W–21,600W 120V/240V Split-Phase Output
- 6.1kWh LFP Stackable Battery (scales to 30kWh–90kWh)
- 5,600W Solar Input — Zero Roof Permit Required for Portable PV
Renogy 48V Off-Grid & Hybrid LFP Solar Kit
Complete modular 48V architecture combining high-efficiency N-type bifacial panels, a 48V 3,500W–5,000W MPPT inverter-charger, and smart modular LiFePO4 storage at ~$1.15/W hardware cost.
- 48V High-Efficiency Bus (75% lower copper wire loss)
- Modular 48V 50Ah / 100Ah Smart LiFePO4 Battery Bank
- Complete Plug-and-Play MPPT All-in-One Controller
Auditor Disclosure: Solar Ledger never sells your contact information to solar telemarketers. Outbound partner links (/go/...) may earn a referral commission at zero additional cost to you.