Power Reduction at Low Battery (State of Charge)
As your Powerpack charge drops below certain thresholds, your FONZ automatically reduces available power output. This is expected, protective behaviour. This article explains what to expect and how it differs across models.
Why does this happen?
Electric vehicles (including every FONZ model) use battery cells that can only safely deliver a limited amount of current at low charge levels.
If full power were drawn from a nearly depleted PowerPack, it would place excessive strain on the cells and significantly reduce overall battery lifespan.
To protect both the rider and the PowerPack, the FONZ onboard battery management system automatically reduces power output as the battery charge decreases.
You may notice this as:
- Reduced throttle response
- Lower top speed
- Softer acceleration
This behaviour is intentional and expected. It is a built-in safety and longevity feature.
What to expect at low charge
The point at which power reduction begins varies depending on the model and Powerpack configuration:
- Single PowerPack models (Arthur 1 and Arthur 2)
These earlier models will reach the power management threshold sooner, so performance reduction may be noticed earlier as the battery depletes. - Dual Powerpack models (Arthur 6 and later)
These models can draw power across two batteries simultaneously, reducing stress on each individual pack. This allows them to maintain stronger performance at lower charge levels. - Z Series models
These use higher discharge-capable cells, meaning each cell operates under less stress. As a result, full performance can be sustained to a lower overall state of charge. - NKD Series models
These Powerpacks are built with a higher-capacity cell configuration (more cells in parallel within each pack), which reduces the load on each individual cell. This allows the system to sustain full performance down to a lower overall state of charge.
Tips to avoid reduced performance during a ride
To maintain consistent performance and avoid power limiting mid-journey:
- Charge before reaching low levels
We recommend charging at around 20% state of charge (SOC) - Top up regularly
FONZ Powerpacks do not develop memory, so frequent charging has no negative effect - Plan ahead for longer rides
Check your estimated range and allow a buffer - Account for riding conditions
Hills, headwinds, passenger weight, and sustained high speeds will increase energy consumption
Key takeaway
If your FONZ reduces power at low battery, it is operating exactly as designed - protecting your PowerPack, preserving long-term performance, and ensuring safe operation.