How does charge point ranking work in Monta?
How Monta calculates and ranks charge point models and brands, including ranking thresholds, the rolling average methodology, and the four performance measures: uptime rate, user satisfaction rate, charge success rate, and performance score.
Monta has developed a ranking system for charge point brands and models. You can see model rankings on the supported charge points page. Brand rankings are available in Monta's Hardware Portal.
Charge point rank
The ranking is a first indicator of how well a charge point performs on Monta. It is available at the model level on the supported charge points page, and at the brand level in the Hardware Portal.
Thresholds
A minimum data threshold must be met before a model is ranked. Models below these thresholds appear as "not ranked" but may still have individual measures associated with them.
- At least 50 charge points of the model connected to Monta
- At least 200 successful charges completed on the model
- At least 30 daily performance score values within a 90-day period
Time dimension
The rank is a trend indicator of a brand or model against its competition. The actual rank is based on a 30-day rolling average performance score, not daily scores. This prevents day-to-day fluctuations while remaining representative of recent trends.
Rolling average formula: the average of (daily performance score + sum of rolling average performance scores over the last 30 days).
- If no daily performance score exists for a given day, the previous day's rolling score is carried forward.
- For new models with fewer than 30 days of data, the average is built over the available data.
Example rolling average calculation:
| Day | 1 | 2 | 3 | 4 |
| Daily performance | 100 | 50 | 80 | null |
| Rolling performance | 100 | 75 | 85 | 85 |
What are charge point measures?
Rankings are built from four measures following a key performance indicator (KPI) tree approach, similar to a DuPont analysis. All measures are represented as a percentage between 0% and 100%.
Metrics are aggregated across three levels:
- Individual charge points — calculated from all data for that specific charge point.
- Charge point models — aggregated across all charge points of that model.
- Charge point manufacturers — weighted averages of all models produced by the manufacturer.
Example: If one model accounts for 80% of a manufacturer's installation base and another for 20%, the first model has a proportionally larger impact on the manufacturer's scores.
Measure 1: Uptime rate (UR)
Uptime measures the percentage of time a charge point is available for service. Monta calculates uptime based on the OCPP (Open Charge Point Protocol) state of Connector 0, as defined in OCPP specifications section 7.7.
| State | Condition | Counted towards uptime |
|---|---|---|
| Available | Connector available for a new user (operative) | Yes (operative) |
| Unavailable | Connector unavailable due to a Change Availability command or charge point discretion (inoperative) | No (inoperative) |
| Faulted | Charge point or connector has reported an error and cannot deliver energy (inoperative) | No (inoperative) |
Start condition: First three successful charges above 1 kWh. After this, the charge point contributes to the model's and brand's uptime.
End condition: No OCPP communication from the charge point within 14 days. The charge point is excluded from the calculation and the 14 days of offline time are retroactively removed. Any OCPP communication (heartbeats, boot notifications, etc.) within the 14-day window resets the timeframe.
Measure 2: User satisfaction rate (USR)
Drivers using Monta Charge can rate a charge session from 1 to 5 stars. These ratings are aggregated per model and converted to a percentage as follows:
| Star rating | Percentage |
|---|---|
| 1 | 0% |
| 2 | 25% |
| 3 | 50% |
| 4 | 75% |
| 5 | 100% |
All ratings are weighted equally. The final score is the average of all ratings given. Driver feedback is available in Monta's Hardware Portal.
Measure 3: Charge success rate (CSR)
The CSR measures the reliability of a charge point model by analysing the outcome of charging sessions initiated by drivers — specifically the percentage of sessions that result in a successful energy transfer.
A successful charge is:
- A session where energy (in kWh) is delivered to the vehicle.
- A session where no critical errors occur, even if no energy is delivered — for example, when smart charging delays energy transfer or the user cancels before charging starts.
A failed charge occurs when:
- The session ends due to critical errors that prevent energy delivery, such as connector faults or hardware malfunctions.
- The session ends prematurely due to issues outside user or system control, such as communication failures or charge point errors.
Measure 4: Performance score
The performance score is calculated once daily using the three measures above for each model. The score is used as the basis for the 30-day rolling average that determines the final rank.