Rechargeable Cells And Battery Packs From One Factory
Custom Packs Built To Your Drawing
Sunder builds LiFePO4, lithium ion, lithium polymer and Ni-MH packs to the voltage, capacity, footprint and connector your product needs. Cell selection, BMS, wiring and case are all decided with your engineer before the first sample.
LiFePO4 Packs That Outlive The Lamp Head
More than 2000 cycles at 80% DOD, a -20℃ to 60℃ discharge window and IP55 ABS housings that drop into the same pole box as the lead acid battery they replace.
High Rate 18650 Packs For Tool Makers
11.1V 18Ah, 12V 4400mAh and other ICR18650 configurations with 1C continuous discharge, protection board and the terminal your tool housing already uses.
Frog Bottle And Silver Fish E-bike Batteries
24V, 36V and 48V 10Ah 18650 packs supplied with BMS, charger and aluminium case in the three standard e-bike form factors.
- LiFePO4, lithium ion, lithium polymer and Ni-MH
- More than 2000 cycles on the LiFePO4 range
- 3.2V single cells up to 51.2V 1000Ah cabinets
- Manufacturing in Shenzhen since 2008
What We Make
LiFePO4 cells and packs, 18650 lithium ion packs, lithium polymer cells and Ni-MH cells and packs, from a single 3.2V cell up to a 50kWh storage cabinet.
Who We Serve
Solar lighting and storage assemblers, power tool and appliance brands, e-bike builders, and consumer electronics teams that buy packs rather than cells.
What Problem We Solve
Lead acid that dies in a season, and off the shelf packs that never quite fit. We match chemistry, cell format and case to the duty cycle you actually run.
Why Buy From Us
A factory of 500 workers building rechargeable batteries since 2008, with an R&D and engineering team of more than 10 years in this industry.
Four Chemistries Built In One Factory
Sunder is an OEM and ODM rechargeable battery manufacturer in China. We produce and sell lithium iron phosphate battery, lithium ion battery, li-polymer battery, Ni-MH battery and battery packs for overseas markets.
Products Buyers Ask For Most
Every product page carries the full parameter table, the series and parallel arrangement and the model list for its range.
12V 100Ah LiFePO4 battery
Product: lithium iron phosphate battery · Model name: LFP12100
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5kWh battery
Product: 48V 100Ah 5kWh lifepo4 battery · Model: ESS48100
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3.2V 200Ah LiFePO4 battery
Dimension: 71*182*279mm · Model: LFP71182279
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18650 power tool battery 11.1V 18Ah
Dimension: 57*170*70mm · Model: ICR18650 3S9P
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Solar light battery
Product: 12V 45Ah solar light battery · Model: 26650 4S15P
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Li-polymer battery 900mAh
Dimension: 6.2*30.5*50.5mm · Model: PL603048
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Robot vacuum cleaner battery
Voltage: 14.4V · Capacity: 3000mAh, 3300mAh, 3500mAh, 3800mAh, 4000mAh
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48V lifepo4 battery
Product: 48V 50Ah lifepo4 battery · Model: ESS4850
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12.8V 200Ah LiFePO4 battery packs
Size: 243*258*391mm · Application: solar energy storage
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Electric bike battery
Voltage: 24V / 36V / 48V · Capacity: 10Ah
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Home battery storage
Product: 48V 100Ah 5kWh lifepo4 battery · Dimension: 500*171*500mm
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18650 lithium battery 18Ah
Model: ICR18650 1S7P · Single cell capacity: 2600mAh
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LiFePO4 280Ah
Product: 3.2V 280Ah LiFePO4 battery cell · Dimension: 72*174*205mm
View data sheetSix Industries We Supply
Different duty cycles, different chemistries. Each page sets out the pain points, the products that answer them and the questions buyers ask.
Solar Street Lighting
Rechargeable LiFePO4 battery packs are widely used in solar street lights and energy storage systems, and have a…
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Power Tools
Lithium-ion batteries are extensively used by the power tool industry as they are light weight and carry higher…
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Electric Bikes
Buy green, save green, and see more greens. Switch to lithium battery packs for more efficient e-bike…
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Consumer Electronics
More and more bluetooth products come to market, which increases the demand for lithium polymer battery. Li-polymer…
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Energy Storage
Rechargeable LiFePO4 battery packs are widely used in energy storage systems, with a longer cycle life than lead acid…
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Home Appliances
Ni-MH cells and packs remain the practical choice for appliances designed around 1.2V cells and for the service…
Read moreHow A Project Runs
Most of what we ship did not exist before a customer's drawing arrived.
Custom Battery Pack Development
Sunder is an OEM and ODM manufacturer. Most of what we ship is a pack that did not exist before the customer's drawing arrived.
Lead Acid Replacement
The most common project we run is swapping a sealed lead acid block for a LiFePO4 pack without changing anything else in the system.
Cell Supply And Pack Assembly
Some customers want cells and build their own modules. Some want the module. We supply both from the same cell stock.
Published Company Figures
Only what the company states about itself. Certifications and export figures are not published on this site until they are confirmed in writing.
Where The Packs Are Built
Photographs from our own factory and packing line.
Guides Written For The People Who Specify
Selection, design and maintenance notes built from our own published data.
- How To Choose Between LiFePO4 And Lithium IonBuying Guide
- Reading A Series And Parallel CodeDesign Guide
- Cylindrical Compared With Prismatic LiFePO4 CellsComparison
- Replacing A Lead Acid Battery With LiFePO4Installation Guide
- Charging LiFePO4 Batteries CorrectlyMaintenance Guide
- Choosing A Lithium Polymer Cell SizeDesign Guide
- When Ni-MH Still Makes SenseComparison
Frequently Asked Questions
The questions we answer most often. The full list is on the FAQ page.
What is a li-ion battery?
Li-ion battery mainly refers to the use of lithium in the electrode material as the main active substance of a class of batteries. We normally manufacture rechargeable lithium battery, which is also called secondary battery. It can be repeatedly charged and discharged.
Are li-ion batteries safe?
One should avoid certain things when handling a lithium ion battery. A li-ion battery should not get hot, over-charged, over-discharged or shorted. Battery packs contain a PCB or PCM that prevents over-charge, over-discharge and short-circuit. So the only remaining things to avoid are physically abusing the battery and getting it hot. Do not throw a battery into a fire.
What is the li-ion battery charge voltage?
The charging voltage depends on the li-ion chemistry. If the cathode is composed of LiFePO4, its nominal voltage is 3.2V, so 4 cells in series give a nominal voltage of 12.8V. A LFP cell is typically charged up to 3.65V, which corresponds to 14.6V for 4 cells in series. If the cathode is composed of LCO, its nominal voltage is 3.7V and the maximum charge voltage is 4.2V.
What is the charge current for lithium ion batteries?
The normal charge current is 0.2C to 0.5C, and the maximum charge current is 1C.
How do I charge a lithium ion battery?
CC/CV. For example, charge a LiFePO4 cell at a constant current of 0.2C or 0.5C until the cell reaches 3.65V, then charge at a constant voltage of 3.65V until fully charged at room temperature.
What is a cycle?
A complete cycle refers to the sequential charge and discharge of a battery pack or a cell.