Negotiation of Power: The Role of BMS in Charging Off-Road Equipment

What is the most critical step in electrifying off-road machinery? The simplest answer is replacing the internal combustion engine (ICE) drivetrain with an electric drivetrain. However, that’s just the beginning.

Electrification is a system-wide transformation. Critical decisions exist at every junction—choice of electric motor, inverter, battery chemistry, and more. Rather than any single step, each decision links with the next, collectively shaping performance, reliability, and safety.

Similarly, an OEM’s choice of charging method is not an isolated decision, and negotiating power to a machine is not as simple as plugging into the nearest outlet.

Battery management systems (BMS) are essential in this process. Along with the right charging solution, the BMS ensures safe and efficient power transfer, making it a core component of any electrification strategy.

The Challenge of Charging Off-Road Equipment 

While charging electric vehicles (EVs) may seem straightforward, industrial and off-road equipment face additional considerations.

Unlike ICE, electric equipment must answer the ever-present question: Where do you plug in? 

For OEMs operating in urban zones or commuting with electrified equipment to worksites, the answer may lie in public EV charging stations, otherwise known as electric vehicle supply equipment (EVSE).

EVSE presents a powerful charging solution, but successful integration depends on several factors: 

• Availability of EVSE infrastructure – Projections indicate significant growth in charging infrastructure globally. For OEMs grappling with increasingly stringent emission restrictions in urban worksites, such infrastructure could emerge as a valuable supplement to recharge equipment.
• Compatibility with industrial power needs – Even with EVSE available, not all infrastructure natively supports the stringent requirements of non-road machinery. Voltage levels, connector types, or charging protocol mismatches can render the negotiation mute—unable to supply a charge.
• Machine-level integration – At the other end of the “negotiating table”, the machinery itself requires a means to accept charge. This requires an onboard charging system capable of secure, standards-based communication with the EVSE.

Even with all of these elements in place, bridging the gap requires one additional technology: BMS. 

BMS: The Central Negotiator 

Where compatible hardware and communication protocols provide the infrastructure, a BMS steps in to effectively handle the negotiation of power. Such systems ensures that charging is:

• Safe – The BMS continuously monitors variables such as voltage, temperature, and current. Should any parameter deviate beyond defined thresholds, the system will immediately interrupt charging to prevent hazardous conditions, including thermal runaway.
• Efficient – Intelligent algorithms enable the BMS to manage current flow dynamically, negotiating the “best deal” that both minimizes energy loss and maximizes operational uptime.
• Controlled – When tailored to the battery—and paired with the right charger—an effective BMS executes critical cell balancing functions. This extends battery life, maintains uniform charge distribution, and preserves overall system health.

A coordinated power transfer process where each component operates at its highest potential, guided by the real-time oversight of the BMS.

Five Key Steps to a Successful Negotiation

Yet another question remains: How does the BMS accomplish this safer, more efficient charging? While plugging in is simple, this one motion activates a multi-stage process: 

• Waking up the MCU (microcontroller unit) – BMS begins by waking up the machine’s control systems, initiating communication with the EVSE. This initial handshake is essential for data transfer to begin.
• Negotiating the MCU-EVSE connection – Next, both machine and charging station agree on key parameters—such as voltage levels, current limits, and charging profiles—under which the charge will proceed.
• EVSE activates AC power – With communication validated, the EVSE begins delivering alternating current (AC) power to the system.
• On-board charger activation – The machine’s on-board charger recognizes the incoming power, converting AC into direct current (DC) suitable for battery storage.
• Ongoing diagnostics – Throughout charging, the BMS monitors internal conditions such as cell temperature, voltage uniformity, and state-of-charge (SoC). In case of any abnormalities, the BMS will interrupt or limit the charge to prevent component degradation.

This five-phase protocol unfolds in a matter of seconds, yet reflects years of engineering development and system refinement. The BMS thus optimizes charger performance and ensures end-user safety at every touchpoint.

Is a BMS Always Required? Contextualizing its Role in Electrification

The above example of charging with EVSE is one way to safely charge an electrified machine. However, it is not the only way.

There are several use cases in which a BMS is not required, such as: 

• Fleets managed through centralized, purpose-built off-board chargers that incorporate external safety and diagnostic mechanisms, overlapping with the role of a BMS.
• Machines using on-board charging solutions with integrated protections, designed to operate independently of a BMS while still maintaining high safety and performance standards.
• Designs built on legacy battery architectures, such as lead-acid chemistries, which lack the communication protocols necessary for BMS integration.

In each case, a BMS is either unnecessary, incompatible, or functionally redundant. For OEMs and machine design engineers, this is a crucial takeaway: The key is not whether a BMS is always used, but whether its functions are appropriately covered.

For example, charging systems—such as ZIVAN’s SG9—are engineered from the ground up with embedded safety features that protect against overvoltage, overcurrent, and thermal risk. Other models utilize charging algorithms tailored to the battery (including lead-acid chemistries), enabling many of the same efficiency and longevity benefits associated with a BMS.

ZIVAN: Negotiating Power with a Custom Charging Solution

It’s clear that electrifying off-road equipment is about far more than the battery. Successful, safe, and efficient power transfer hinges on advanced charging technology. 

In scenarios involving EVSE or high-performance lithium-ion systems, a BMS indeed serves as an essential interface. 

However, BMS must be evaluated alongside the capabilities of the charger. 

As demonstrated by the SG9 and other ZIVAN innovations, a well-engineered charging solution can mitigate or even eliminate the need for additional battery-side intelligence, particularly for legacy chemistries or compact machinery applications.

Regardless of design choice, one thing is certain: OEMs require more than single components. They require well-integrated systems that support both present operational needs and future scalability.

ZIVAN, as part of the ZAPI GROUP, offers precisely this combination: robust, chemistry-agnostic charging hardware paired with application-specific expertise. Whether integrating with BMS-enabled systems or designing intelligent standalone solutions, ZIVAN enables OEMs to build the future of electrified mobility with confidence.

Sources: 

IEA. Outlook for electric vehicle charging infrastructure. https://www.iea.org/reports/global-ev-outlook-2024/outlook-for-electric-vehicle-charging-infrastructure

European Union. On the deployment of alternative fuels infrastructure. https://data.consilium.europa.eu/doc/document/PE-25-2023-INIT/en/pdf

Media Contact 
Violetta Fulchiati | Marketing & Communication Specialist 
Phone: +39 0522 960593
E-mail: marketing@zivan.it