Custom EV Battery Systems

EV Battery Systems Engineered Around Your Vehicle

Custom low-voltage and high-voltage lithium battery systems for EV conversions, commercial electric vehicles, and specialty EV platforms - developed around your voltage, power, driving range, installation space, charging, and communication requirements.

  • 48V-700V+ Systems
  • LFP and NMC
  • BMS and CAN Integration
  • Prototype to Production
Get an EV Battery Proposal Discuss Your EV Project

Start with your vehicle, motor, target range, or available space. Incomplete information is enough to begin.

EV chassis with an integrated high-voltage battery system and orange power cables
01

Voltage

Low- and high-voltage development matched to the vehicle and duty cycle.

02

Packaging

Enclosures, mounting, interfaces, and pack layout developed around available space.

03

Communication

BMS, VCU, charger, and CAN requirements reviewed as one vehicle system.

04

Production

Engineering support from initial architecture through pilot and batch production.

Vehicle-First Engineering

Your EV Battery Starts With the Vehicle - Not a Catalog

Two vehicles can share the same nominal voltage and still need completely different battery systems. Motor power, controller current, driving range, payload, installation space, charging, communication, temperature, and validation targets all influence the final architecture.

We begin with the vehicle and duty cycle, then define the battery voltage, usable energy, current capability, chemistry, enclosure, thermal strategy, BMS, protection components, and interfaces.

  • Motor rated and peak power
  • Controller maximum current
  • Vehicle operating voltage
  • Target range or operating time
  • Vehicle weight and payload
  • Available battery envelope
  • Charging voltage and power
  • CAN or VCU communication
  • Operating temperature
  • IP, vibration, and shock requirements
Engineers reviewing battery packaging within an electric vehicle chassis
Packaging, electrical interfaces, and duty cycle are evaluated together before the pack architecture is released.

Application Fit

EV Platforms We Support

Classic vehicle conversion project in a specialist automotive workshop
01

EV Conversions

Classic cars, passenger vehicles, and prototype conversions fitted around an existing chassis.

Electric delivery van and light commercial truck at a logistics depot
02

Commercial Electric Vehicles

Electric vans, delivery vehicles, and light trucks where range, payload, duty cycle, and serviceability interact.

Electric UTV supporting field maintenance at a solar energy site
03

UTV Electric Vehicles

Electric utility terrain vehicles for industrial sites, agriculture, estates, and field-service operations.

Low-speed electric shuttle operating on a landscaped campus
04

Low-Speed EV Platforms

LSVs, patrol vehicles, and sightseeing vehicles that need compact, repeatable integration.

Engineers measuring a camouflaged prototype vehicle during OEM development
05

Custom OEM EV Platforms

New vehicle programs, pilot projects, and low-volume production with coordinated system development.

Architecture Range

From Low-Voltage EVs to High-Voltage Vehicle Platforms

48V-144V

Conversion and Utility Platforms

EV conversions, low-speed EVs, utility EVs, and specialty vehicles.

200V-450V

Passenger and Light Commercial

Passenger EVs, electric vans, light-commercial vehicles, and custom OEM programs.

450V-700V+

High-Power Vehicle Platforms

Commercial vehicles, high-power EV platforms, and special-purpose vehicles.

LFP

Often evaluated when thermal stability and cycle-life potential are important for commercial, utility, or conversion projects.

NMC

Often evaluated when higher energy density is important for space- or weight-sensitive packaging.

Chemistry selection remains project-dependent and is reviewed against packaging, power, thermal, service-life, and market requirements.

System Integration

Built Around Your Vehicle Architecture

The battery is developed as part of the vehicle system, not as an isolated enclosure.

01

Electrical Design

Nominal and operating voltage, usable energy, continuous and peak current, motor and inverter compatibility, and charging power.

02

Mechanical Integration

Dimensions, orientation, mounting points, chassis interfaces, connector positions, weight distribution, and enclosure layout.

03

Controls and Communication

BMS architecture, CAN 2.0 or J1939 where required, VCU and charger integration, SOC/SOH reporting, and fault logic.

04

Environmental Design

Ingress protection, temperature, air or liquid thermal management, heating, vibration, shock, pressure relief, and sealing.

Discuss Your EV Project
Illustrative cutaway of an EV battery system with modules, protection components, and cooling structure
Illustrative EV battery system architecture. Final component selection and layout are developed for each vehicle project.

System Anatomy

More Than Cells in a Box

A complete EV battery system coordinates energy storage, switching, protection, communication, thermal paths, service access, and the vehicle interface.

Cells and modulesBMSCurrent sensorMain contactors Pre-charge circuitFuseMSDHV connectors LV communicationThermal sensorsCooling pathPressure relief Steel or aluminum enclosureOptional PDU

Engineering Starting Points

Representative EV Battery Configurations

Low-voltage

96V EV Conversion System

  • 96V-class architecture
  • LFP or NMC according to project priorities
  • Custom enclosure and connector layout
  • Current matched to motor and controller
  • Single- or split-pack layouts where required

High-voltage

300V-400V Vehicle Battery System

  • Integrated HV protection components
  • CAN communication
  • Thermal management matched to duty cycle
  • Passenger and light-commercial EV development

High-power

500V-700V+ High-Voltage System

  • High continuous and peak power capability
  • Liquid cooling where required
  • HVIL, MSD, fuse, and contactor integration
  • Commercial and high-power EV platforms

These are representative engineering configurations, not fixed catalog products. Final voltage, capacity, current capability, thermal system, and enclosure are developed around each vehicle project.

Battery engineers reviewing vehicle CAD and available installation space

Project Inputs

Start With What You Know

You do not need a complete battery specification to start.

  • Vehicle type and application
  • Motor rated and peak power
  • Motor and controller voltage
  • Controller maximum current
  • Target range or operating time
  • Battery installation space
  • CAD or STEP files
  • Maximum battery weight
  • Charging requirements
  • Operating environment
  • Prototype and annual quantity

Incomplete information is OK. Our engineers can help define the remaining battery parameters.

Send Your Vehicle Requirements

Verified Project Cases

EV Battery Development in Practice

Customer identities are withheld. Details are limited to the project information supplied for this page.

Custom 96V battery enclosure developed for a classic-car EV conversion program

Germany · Repeat conversion program

96V Classic-Car Conversion

Constraint
Compact packaging for an existing vehicle with repeatable dimensions and interfaces.
Engineering response
Vehicle-led enclosure, cell configuration, BMS protection, high-current connections, and mounting design.
Project stage
Progressed beyond prototype development into repeat batch supply.
Custom 332.8V high-voltage battery pack for a light-commercial EV platform

United States · Light-commercial EV

332.8V Vehicle Battery System

Constraint
Energy and power within a fixed space while integrating inverter, charger, communications, and HV safety.
Engineering response
Integrated modules, BMS, HV protection, service disconnect, communication, thermal management, and vehicle connections.
Project stage
Completed engineering and validation and progressed into batch production.
Custom 72V battery pack for electric tuk-tuk and three-wheel vehicle production

Thailand · Three-wheel commercial EV

72V Tuk-Tuk and Electric Tricycle

Constraint
Frequent daily use, repeated cycling, high ambient temperature, vibration, and a compact chassis envelope.
Engineering response
A robust 72V pack with BMS protection, high-current output, thermal design, and repeatable interfaces.
Project stage
Completed vehicle integration and validation and progressed into ongoing batch production.

Development Path

From Vehicle Requirements to Production Battery

  1. 01

    Requirement Review

    Vehicle, motor, inverter, range, packaging, environment, charging, communication, and volume inputs.

  2. 02

    Battery Architecture

    Voltage, energy, chemistry, current capability, BMS strategy, and protection concept.

  3. 03

    Mechanical Integration

    Cell or module layout, enclosure, mounting, service access, and connector positions.

  4. 04

    Electrical and Thermal Design

    HV protection, communication, cooling, heating, and the charging interface.

  5. 05

    Prototype Manufacturing

    Prototype pack build in the agreed configuration for vehicle integration work.

  6. 06

    Validation

    Applicable electrical, insulation, communication, thermal, sealing, vibration, and enclosure checks.

  7. 07

    Pilot Production

    Small-batch verification of build, inspection, and integration repeatability.

  8. 08

    Batch Production

    Controlled production, inspection, documentation, and delivery after project release.

Build and Verify

EV Battery Manufacturing and Validation

Battery module assembly equipment at the Bonnen production facility

Module Production

Cell and module processes are completed according to the released design and selected components.

Laser welding process used during battery module manufacturing

Joining and Integration

Joining and electrical interfaces follow the process specified for the cells, busbars, modules, and enclosure.

Electrical functional testing of a battery pack at the Bonnen facility

Electrical Functional Testing

Electrical checks verify the released configuration and applicable pack functions before delivery.

Battery pack airtightness testing at a production test station

Pack Sealing Checks

Airtightness and enclosure sealing checks are applied where required by the project validation plan.

Global Project Support

Documentation and Compliance Support for Global EV Projects

Depending on the final design and destination, project documentation may include UN38.3 transport test documentation, MSDS, dangerous-goods shipping documents, quality-management evidence, and support for CE, IEC, or CB requirements where applicable.

Documentation and certification requirements are reviewed according to the final battery design, vehicle category, and destination market.

  • 01Transport and shipping documentation
  • 02Quality-management evidence
  • 03Market-specific requirement review
  • 04Project-level test and document planning

Compliance support does not mean every battery configuration carries the same approvals. Applicable standards, test scope, document ownership, and market requirements must be confirmed during the project.

FAQs About Custom EV Battery Systems

Practical answers for EV manufacturers, vehicle conversion companies, system integrators and engineering teams developing custom lithium battery systems for electric vehicles.

Yes. Bonnen Battery develops custom lithium battery systems based on the vehicle voltage, motor and inverter requirements, installation space, required driving range, continuous and peak current, charging system and operating environment. We can support passenger vehicles, light commercial vehicles, classic car conversions, utility vehicles and other specialized EV platforms. A project can start from complete CAD drawings or from basic information such as voltage, capacity, available space and motor power.

Battery voltage should normally be matched to the motor, inverter and overall vehicle electrical architecture, while battery capacity depends mainly on the required driving range and expected energy consumption. A preliminary estimate can be made from the vehicle’s average energy consumption in kWh per kilometer or mile, but final sizing should also consider usable battery capacity, vehicle weight, driving conditions, auxiliary loads, reserve energy, discharge current and expected battery life.

The most useful information includes the required system voltage, target capacity or driving range, motor rated and peak power, inverter current, available battery installation dimensions, charging requirements, communication protocol and operating temperature range. CAD or STEP files are helpful for mechanical integration, but they are not required at the beginning. If some project information is not yet available, we can start with the known parameters and identify the remaining engineering inputs during development.

Yes. The enclosure and internal battery layout can be developed around the available vehicle space. We can evaluate maximum length, width and height, mounting points, cable routing, service access, connector position and weight distribution. For projects with limited packaging space, a CAD or STEP model of the battery compartment is especially useful because it allows the battery structure and cell arrangement to be evaluated before the detailed mechanical design is finalized.

Yes. A battery system can be designed as one enclosure or divided into two or more battery boxes depending on the vehicle structure and available installation space. Split battery systems are commonly considered for classic car conversions and vehicles where the battery must be distributed between front, rear or underfloor compartments. The electrical architecture, protection strategy, BMS communication, HV interconnection and service isolation should be designed as one complete battery system.

The correct chemistry depends on the project priorities. LFP is commonly selected when cycle life, thermal stability and long-term durability are more important, while NMC may be preferred when higher energy density and lower battery weight are critical. The decision should also consider available installation space, required vehicle range, operating temperature, discharge power, charging strategy and expected service life. We can evaluate both options based on the vehicle requirements rather than selecting chemistry only by energy density.

The battery must be sized for both continuous operating current and short-duration peak current. Motor power alone is not enough because actual battery current depends on system voltage, inverter efficiency, acceleration demand, regenerative braking and operating conditions. We normally review motor rated power, peak power, inverter current limits and expected duty cycle before selecting the cell configuration, busbar design, contactors, fuse and BMS current capability.

Yes. Custom EV battery systems can support CAN communication with vehicle controllers, inverters, onboard chargers and other vehicle systems. Depending on the project, communication may include battery voltage, current, SOC, SOH, temperature, alarms, charge and discharge limits and system status. Existing CAN protocols can be reviewed for compatibility, or communication requirements can be defined together during development. CAN database or protocol documentation is helpful when available.

The charging system should match the battery voltage range, maximum charging current and vehicle architecture. Custom EV batteries can be designed to work with onboard chargers, external chargers or other charging solutions depending on the application. During battery development, the charger output voltage, charging power, CAN communication requirements, charge cut-off conditions and low-temperature charging strategy should be reviewed together to ensure safe and reliable charging performance.

Not every EV battery requires liquid cooling. The correct thermal management method depends on cell chemistry, continuous and peak power, charging rate, ambient temperature, battery enclosure design and vehicle duty cycle. Some lower-power systems may use passive cooling or air cooling, while higher-power or more demanding applications may require liquid cooling. Thermal management should therefore be selected from the actual heat generation and operating profile rather than from battery capacity alone.

Battery testing can include electrical performance verification, BMS protection testing, insulation checks, temperature monitoring, communication testing and other project-specific validation. For international transportation, UN38.3 and supporting shipping documentation can be provided where applicable. Additional certification or compliance requirements depend on the destination market, vehicle category and customer project, so these requirements should be identified early in the development process.

Yes. Many custom EV battery projects begin with one or several prototype packs for vehicle integration, communication testing and road validation before moving into pilot or batch production. Keeping the electrical architecture, mechanical structure, cell selection and key components consistent from the prototype stage can help reduce redesign work later. After validation, the design can be finalized for repeat production with controlled drawings, BOMs, testing procedures and production quality requirements.

Begin With Your Vehicle

Tell Us About Your EV Project

Share your motor voltage, power, target range, available battery space, or vehicle CAD. Even incomplete project information is enough to start.

Get an EV Battery Proposal

Include your vehicle type, motor or inverter data, available space, charging needs, operating environment, and expected quantity if known.