Building a LiFePO4 pack is mostly discipline — EGbatt lays out the steps our own line follows so your build is safe, balanced and repeatable.

Overview

A LiFePO4 pack is cells arranged in series (voltage) and parallel (capacity), a BMS to protect and balance them, busbars to carry current, and an enclosure rated for the duty. The discipline that separates a good pack from a dangerous one is cell matching: every parallel group should have near-identical capacity and internal resistance, or it drifts and one cell carries the load. EGbatt grades cells, spot-welds or bolts busbars to spec, integrates a BMS matched to the topology, and validates on capacity, IR balance and thermal behaviour. Below is the method, whether you build in-house or have us build it.

Key specifications

SpecificationValueWhy it matters TopologySeries = voltage, parallel = capacity4S=12.8V, 8S=25.6V, 16S=51.2V. MatchingEqual capacity & IR per groupPrevents drift. BMSProtects + balancesMatched to S-count and current. BusbarsRated for currentLow-loss connections. EnclosureIP + thermal per dutyStationary vs mobile.

Typical applications

  • OEM in-house build: Follow the method.
  • Custom pack project: Spec to EGbatt.
  • Repair/upgrade: Rebuild safely.
  • Learning: Understand your supplier.

How to specify & buying guide

  • Match cells within 0.2 mΩ IR and a tight capacity band per parallel group.
  • Size the BMS to the series count and peak current; pick passive vs active balancing by pack size.
  • Rate busbars and fuses for the pack's continuous and fault current.
  • Validate the finished pack on capacity, IR balance and thermal rise before service.

Engineering & manufacturing at EGbatt

Our guides are written by the same engineering team that grades the cells and builds the packs. They are meant to help importers, installers and procurement specifiers make defensible decisions — not to rank for a keyword.

Certifications & compliance

  • UN38.3 — Mandatory lithium battery transport test (altitude, thermal, vibration, shock, external short). Required for any cross-border shipment.
  • IEC62619 — International safety standard for industrial Li-ion cells and batteries; expected by EU and most APAC buyers.
  • CE — EU declaration of conformity for the applicable directives.
  • RoHS — Restriction of hazardous substances in the battery and BMS.

Frequently asked questions

What is the hardest part?

Cell matching — unequal cells drift and one carries the load.

How many cells for 48V?

16 in series (16S) for 51.2V; parallel groups add capacity.

Passive or active balancing?

Passive for typical packs; active for large series strings.

Can EGbatt build it for me?

Yes — custom pack design is a core OEM/ODM service.

Related products & resources

  • Custom Pack Design
  • BMS
  • LiFePO4 Cells

Request a quote

Send us your voltage, capacity, dimensions, certification target and annual volume. Our engineering team returns a proposal within three working days. Start your RFQ or review our custom pack capabilities.

Request a LiFePO4 quote

Tell us your product, volume and specs — our engineering team returns a proposal within three working days.

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