Most EV owners have no idea what they actually spend on charging. They know their home electricity rate and have a vague sense of public charging costs, but the real blended rate, the number that determines your actual monthly spend, remains a mystery. Without tracking, you can't optimize, and you can't accurately compare your EV costs to the petrol car you replaced.
How to Track Your Real EV Charging Expenses
Tracking reveals patterns you'd never notice otherwise. You might discover that 25% of your charging happens at expensive public DC chargers because you undercharge at home on certain days. Or that your winter costs are 70% higher than summer due to increased consumption and pricier electricity. These insights are actionable: once you see the pattern, you can adjust your behavior.
Accurate records are also valuable for tax purposes in some countries. Self-employed drivers and company car users may be able to deduct charging costs. Having detailed session logs with dates, amounts, and receipts makes tax time straightforward and ensures you capture every legitimate deduction.
What to Record for Each Charging Session
Every charging session should capture five key data points: date and time, location (home, work, or specific charger), energy delivered (kWh), cost paid, and starting/ending SOC. These five fields let you calculate your cost per kWh at each location, your average cost per kWh across all charging, and your cost per kilometer driven.
Additional useful fields include charger type (AC/DC), charging network, peak power achieved, and session duration. These help you evaluate whether network subscriptions are worthwhile, which chargers deliver their advertised speed, and whether time-based billing is costing you more than per-kWh billing would.
For home charging, recording cost requires a small calculation since your electricity bill doesn't separate EV charging from household use. A dedicated EV energy meter (built into most smart wallboxes) solves this. Alternatively, multiply the kWh delivered (shown in your car's app) by 1.08 (to account for AC efficiency losses) and then by your electricity rate. This gives a close approximation of the grid energy consumed and its cost.
Manual vs Automated Tracking Approaches
The simplest approach is a spreadsheet. Create columns for the key data points and enter each session manually. This takes 30 seconds per charge and works well if you charge 3-5 times per week. The advantage is total control over your data and the ability to add custom fields or calculations. The downside is the discipline required: miss a few sessions and your data becomes unreliable.
Automated tracking through your car's app or charging network accounts is more convenient but fragmented. Tesla, BMW, and others provide charging history in their apps, but only for sessions initiated through their systems. Network apps like ChargePoint or Shell Recharge track sessions on their network only. You end up piecing together data from multiple sources, often in incompatible formats.
Smart wallboxes offer the best automated home tracking. Devices from Easee, Wallbox (Pulsar), or myenergi (Zappi) log every home session with precise kWh readings, timestamps, and even solar vs grid energy breakdowns. Combined with a centralized logging tool, you can merge home and public charging data into a single, comprehensive view of your costs.
Using Plan EV Charge Session Logging and Dashboard
Plan EV Charge includes a built-in session logger designed specifically for EV charging expense tracking. After each charging session, log the key details: your vehicle, the charger used, energy delivered, cost, and SOC range. The platform stores your history securely and lets you review sessions by date, location, or vehicle.
The dashboard aggregates your data into actionable insights. See your average cost per kWh across all charging types, your monthly spending trend, and a breakdown of home vs public charging costs. The system highlights your most and least expensive charging sessions, making it easy to spot opportunities for savings.
Over time, your session log becomes a powerful planning tool. The prediction engine analyzes your charging patterns to recommend optimal charging times and suggest when to charge at home versus when public charging makes sense for your schedule. Combined with the charging calculator, you can simulate future sessions with real cost data from your history, making budgeting for road trips and monthly expenses highly accurate.
