LP-HV-256 high voltage LiFePO4 battery pack

It is a system, not a component

Below about 100 V, a battery pack can be bought as a product. Above it, the pack becomes a system with electrical, thermal and safety design that has to be documented — for the certification body, and in most markets for the installer.

Four things are mandatory at this level and are all included in this platform:

• Master-slave BMS with one slave board per module measuring its own cells and temperatures, and a master that aggregates the stack, computes state of charge and health, and drives the contactors.
• Pre-charge circuit to protect the inverter's DC link and avoid welding a contactor on connection.
• Insulation monitoring to earth, with a contactor trip when isolation resistance degrades. Above low voltage, an earth fault is a hazard rather than a nuisance.
• Documented service disconnect — a lockable isolation point and protection coordinated with the inverter's own DC protection.

What we need to quote

High-voltage work is quoted from a requirement rather than a catalogue page. Send the inverter's DC voltage window, the continuous and peak power, the maximum charge and discharge current, the ambient conditions, the space available and the certification target. We return a single-line diagram, a module layout and a price for approval before any hardware is built.

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