Your OEM / ODM engineering partner

Battery packs and chargers. Built around your device.

OEM / ODM engineering, from your first requirements to samples, testing and production.

In-house engineering · Small-quantity orders accepted

Black single-bay charger with a sloped cradle, four gold contacts and a front indicator
Single-bay charger · retouched product photograph
Engineering
Battery packs & chargers
Development
Circuits & prototypes
Validation
In-house Battery Lab
Production
ISO 9001 manufacturing
Quality
Testing & traceability

PRODUCTSBattery packs & chargers

See the products behind the engineering.

Battery-pack formats and two charger designs, shown in real product photographs. Explore the physical format before discussing your project requirements.

Blue cylindrical battery pack with short colored leads and a white connector
Wired cylindrical battery pack · product photograph

Wired battery pack

A cylindrical format with a lead-and-connector interface.

Explore the details →
Black e-bike battery housing with a through carry handle and charge indicator panel
E-bike battery housing with handle · background-retouched product photograph

E-bike battery housing

A handled housing shown as an e-bike format example.

Explore the details →
Green wrapped backup battery with red and black leads and a white connector
Backup battery format · product photograph

Backup battery format

A compact wrapped format with separate lead wires.

Explore the details →
Black sloped charger with four visible gold contacts
Single-bay charger · retouched product photograph

Single-bay charging cradle

A recessed interface in a sloped charging base.

Explore the details →
Black charging base with a shaped red insert
Single-bay charger · product photograph

Shaped charging cradle

A raised insert defines the battery position.

Explore the details →
Sheet 01 Battery PCB · protection circuitRedrawn from our battery PCB design
Lithium-ion cell circuit with three-level protection: a PTC on the P+ line (2nd protection); on the P− line a Japan IC with over-charge, over-discharge and over-current protection driving a MOSFET (1st protection), then a second Japan IC with over-charge protection driving a MOSFET (3rd protection). Lithium Ion Cell Circuit 2nd protection 1st protection 3rd protection Li-ion Battery PTC P+ Japan IC Over charge protect Over discharge protect Over current protect MOSFET Japan IC Over charge protect MOSFET P− OUTPUT 1 2 3
Three-level protection circuit (redrawn from our battery PCB design)

01How protection is engineered

A closer look at battery protection

Explore an example of our battery PCB protection design. Use Next to explore the protection circuit.Use Next to explore the protection circuit.

  1. 11st protection

    Protection IC + MOSFET

    A Japanese protection IC checks for over-charge, over-discharge and over-current, and controls a MOSFET on the P− line.

  2. 22nd protection

    PTC

    A PTC sits in series on the P+ output line as a separate, second level of protection.

  3. 33rd protection

    Second protection IC + MOSFET

    A second Japanese protection IC adds its own over-charge protection, with its own MOSFET on the P− line.

  4. P±Output

    To your device's P+ / P− contacts

    Three levels stand between the cell and your device. We design this battery PCB to fit your pack and device.

1 of 4

Send your specsSee the project path

02Project path

From your requirements to a tested, traceable shipment

Six stages. Select each one to see what we do, what we need from you, and the equipment or record behind it.

Stage 01 of 06

Requirements

Tell us what the pack or charger has to power and where it has to fit.

What CHYI FENG does

  • Our in-house engineering team reviews your device and how it is used.
  • We list what is needed to start the design and help you fill the gaps.
  • We tell you which certification documents exist for certified models, on request.

What you provide

  • The device or application
  • Voltage and capacity, or the runtime you need
  • Size limits and the connector or contacts
  • Whether you also need a charger
  • Quantity stage: prototype, pilot run or production
  • Unknown values are fine. We work them out with you.
Build a spec brief

01Project checkpoint

Define the interface

  1. Device & application
  2. Space & connection
  3. Runtime & charging

Discuss your project with our engineering team.

Stage 02 of 06

Circuit design

We design the battery PCB (protection circuit) and the charger PCB in-house.

What CHYI FENG does

  • Battery PCB with three levels of protection: Japanese protection IC + MOSFET (1st and 3rd), PTC (2nd).
  • Protection IC for over-charge, over-discharge and over-current.
  • Fuel gauge (gas gauge) for smart batteries when your device needs it.
  • Charger PCB designed to match your pack.

What you provide

  • Charge and discharge needs of your device
  • Connector pin-out or contact layout
  • Whether the battery must report its charge level (fuel gauge)
  • Standards your market requires
See how protection is engineered
Schematic of a lithium-ion cell circuit with three protection levels: two Japan IC and MOSFET pairs on the P− line and a PTC on the P+ line
Fig. 2Three-level protection circuit (redrawn from our battery PCB design)

Stage 03 of 06

Prototype

We build prototype packs and chargers so you can check fit and function in your device.

What CHYI FENG does

  • Prototype packs and chargers built in our own production.
  • Small quantities accepted, so samples and pilot runs are possible.
  • Design changes made after your feedback, with quick, flexible production.

What you provide

  • Fit and function results from your device
  • Changes you need before validation
See charger types

03Project checkpoint

Review the sample

  1. Fit in your device
  2. Check the connection
  3. Confirm your requirements

Discuss your project with our engineering team.

Stage 04 of 06

Battery Lab validation

Our in-house Battery Lab has equipment for the UN 38.3 test items T1 to T8, plus an explosion-proof test chamber.

What CHYI FENG does

  • T1Altitude simulation
  • T2Thermal
  • T3Vibration
  • T4Shock
  • T5External short circuit
  • T6Crush / impact
  • T7Overcharge
  • T8Forced discharge

Plus an explosion-proof test chamber. Certification documents for certified models are available on request.

What you provide

  • The markets you sell into
  • The standards or documents your customers ask for
See the Battery Lab
Room with rows of white battery test chambers
Fig. 4Test chambers in our Battery Lab

Stage 05 of 06

Production

Products are manufactured under ISO 9001, and every product carries a printed traceability code.

What CHYI FENG does

  • Incoming materials and cells are tested before production.
  • Manufacturing under ISO 9001.
  • A printed code on every product records who built it, which process step and the date code.
  • Small-quantity and flexible production.

What you provide

  • Approved sample and final specification
  • Order quantity and delivery schedule
  • Label or marking requirements
How traceability works
What the traceability code records
Who built itEach worker has a code
Which process stepEach process step has a code
Which productEach product has its own code
WhenDate code
Fig. 5What the printed traceability code records

Stage 06 of 06

QC report & shipping

Every battery pack is tested, and a QC test report ships with every shipment.

What CHYI FENG does

  • Every battery pack tested before packing.
  • QC test report included in every shipment.
  • Packed to SOP in export cartons.
  • Express shipping to the US and Europe by UPS or FedEx.

What you provide

  • Ship-to address
  • Preferred carrier: UPS or FedEx

06Project checkpoint

Release with records

  1. Battery-pack testing
  2. QC report with shipment
  3. Packing to SOP

Discuss your project with our engineering team.

01Product families

Starting points you can customize

Explore a battery family or charging configuration. The final design starts with your device and requirements.

Capability A · Battery

Custom battery packs

Packs built around your device: cells, size, connector and protection circuit.

Capability B · Battery

Smart batteries

Battery packs with a fuel gauge (gas gauge) that reports the charge level.

Capability C · Battery

Backup batteries

Small NiMH or lithium cells with leads, for memory backup.

Capability D · Battery

NFC batteries

Battery packs with NFC. Tell us your device and we confirm what is possible.

Capability E · Battery

E-bike batteries

Battery packs for e-bikes, from the same engineering team and lab.

Capability F · Charger

Single-bay chargers

One pocket, matched to your pack and its contacts.

Capability G · Charger

Dual-bay and 4-bay chargers

Two or four batteries charged in one base.

Capability H · Charger

6-bay and multi-bay chargers

Larger chargers for fleets of devices, with our own charger PCB.

04Proof you can check

Engineering backed by testing and records

Ask for any of these when you evaluate us as a supplier.

Battery Lab room with stacked white test chambers

In-house Battery Lab

Equipment for the UN 38.3 test items T1–T8 and an explosion-proof test chamber.

See the test equipment
TESTRECORDSHIP

QC report with every shipment

Every battery pack is tested. The QC test report ships with the goods.

See QC and packing
WorkercodeStepcodeProductcodeDatecode

Traceability code

Each worker, each process step and each product has its own code, printed with the date code.

How it works
  • UL
  • UN 38.3
  • CE
  • IEC 62133
  • IP67
  • BSMI
  • PSE
  • IEC 61960
  • UL 2054

Certification documents

Documents for certified models are available on request.

Request documents

05Start a project

Send your specs, even the ones you don't know yet

The spec brief builder turns your requirements into a clean summary you can email to our engineers. Leave blank anything you are not sure about.

Or contact our sales team directly

sales@chyifeng.com.tw +886-2-2903-0918

New Taipei City, Taiwan