Having a custom battery manufactured: What you need to decide before placing your order

A custom battery is designed based on the machine itself, not the other way around. Before placing an order, you need to determine six key factors: the voltage accepted by the controller, the desired energy for the range, the current required by the controller, the actual available space, the connectors and the BMS (Battery Management System), and finally, the charging method. A well-defined request will address these questions, or at least provide the information needed to answer them. Here is a list of what the workshop will ask you, and why.

1. Voltage: The voltage the machine accepts

The voltage of a battery depends on the number of cells connected in series. It must remain within the controller's voltage range, including the fully charged state, with some margin to accommodate regenerative braking, which increases the voltage. The display, the converters that power the lighting, and the charger must also be able to handle this voltage range.

Increasing the voltage provides higher top speed, but it's a comprehensive project that affects all other aspects of the machine. Our guide explains how to increase the voltage of your scooter and covers all the related considerations.

2. Power: Desired range

The energy, in watt-hours, is the product of the voltage and the capacity. Start with your actual measured consumption and the desired distance, with a margin. The calculation is detailed in Wh, Ah, volts: calculating battery capacity. More energy means more cells: this adds weight, volume, and a longer charging time.

3. Current: The requested power

This is the question that is most often overlooked. The controller, or controllers in the case of a dual-motor setup, will draw a certain peak current and an average current. The battery must be able to supply this current without cutting out or overheating excessively. This current determines:

• the type of cell (energy or power), compared in our guide Molicel P45B, Samsung 50S, P42A, or 40T;
• The number of cells connected in parallel
• The section covers internal connections and output cables
• The BMS calibration.

Please provide the reference number and settings of your controller; this is the starting information.

4. The Space: Measure before you dream

A battery is built within a certain volume. Measure the interior space of the deck or frame (length, width, height, but also any constrictions, screws, and cable passages) and note what else needs to coexist with the battery: controllers, wiring, ventilation. On a scooter, a large battery may require moving the controllers out of the deck or extending the frame. On a lightweight electric motorcycle, the size and weight affect the handling, as explained in our guide larger battery for Sur-Ron or Talaria.

5. Connectors, BMS (Battery Management System), and Enclosure

The connectors

The discharge connector must be sized for the current, and the charging connector can be separate or common. The length and gauge of the output cables must also be appropriate for your machine. Specifying the existing connector avoids the need for an adapter, which is always a potential weak point.

The Battery Management System (BMS)

At this stage, the current rating, port type (common or separate charging), balancing, and connection (Bluetooth, connection to the controller) are determined. A connected BMS (Battery Management System) allows you to monitor each cell group and simplifies diagnostics throughout the battery's lifespan.

The enclosure

Depending on the application, the battery is protected by a sheath and secured within a closed deck, or by a dedicated enclosure: aluminum, 3D-printed part, or a waterproof enclosure with a pressure valve for machines exposed to water and mud. We design and manufacture these enclosures on demand, with our offering of custom enclosures.

6. Charging

What charger should I use? The original charger if the voltage doesn't change; otherwise, a charger with the new voltage. If you're interested in fast charging, you need to plan for it from the beginning: the BMS, the charging connector, and the charging cables must be sized accordingly.

And beyond the scooter..

For a vehicle or machine that doesn't yet exist, or for a fleet, the battery is designed in conjunction with the motor and controller, sized to match the machine's requirements. This is the work of our electric motorization engineering department.