High-Voltage LiFePO4 Battery Packs (100 V – 800 V)

What changes above 100 V

A low-voltage pack is a self-contained product. A high-voltage stack is an engineering project with electrical, thermal and safety design that must be documented for the certification body and, in many markets, for the installer.

The four additions that matter:

• Master-slave BMS. Each series module carries a slave board measuring its own cells and temperature; a master unit aggregates the stack, calculates state of charge and state of health, and controls the contactors.
• Pre-charge circuit. The inverter's DC-link capacitance looks like a short circuit at the instant of connection. Without a pre-charge resistor and correctly sequenced contactors, the inrush will weld a contactor or trip the fuse.
• Insulation monitoring. Above the low-voltage threshold, an insulation fault to earth is a hazard rather than an inconvenience. The BMS must measure isolation resistance and open the contactors when it degrades.
• Service disconnect and fusing. The stack needs a documented, lockable isolation point and protection coordinated with the inverter's own DC protection.

Typical configurations

Our standard high-voltage platforms are built around a 51.2 V module as the repeatable unit — the same module used in our 48 V and rack products. Stacking 5, 8, 10 or 16 modules gives 256 V, 410 V, 512 V or 819 V nominal, which covers most commercial three-phase inverters and containerised systems.

What we need from you to quote

High-voltage work is quoted from a requirement, not from a catalogue. Send the DC voltage window the inverter accepts, the continuous and peak power, the maximum charge and discharge current, the ambient temperature range, the installation space and the certification target. We return a single-line diagram, a module layout and a price for approval before anything is built.

On most projects this takes one exchange of documents. Where the customer already has an inverter and a grid-code requirement, we start from the inverter's DC specification and work backwards to the stack.