DIY battery packs must have the cells balanced (same voltage) before assembly. Returns are not accepted for incorrect assembly or lack of assembly knowledge. Professionals detect voltage, resistance, and appearance before every shipment. We ensure that the single battery is good. Upon arrival, you can test the cells within 15 days. After this period, it is assumed the batteries are in good order and no returns or refunds will be provided. If you find problems, contact us for a return or refund. Returned batteries must be unused (electrodes intact, no welding, no wear, and appearance in good condition). The buyer is responsible for return shipping fees.

5 years (from the date of successful delivery). If the single battery capacity drops below 80% of its initial capacity, please send test pictures or video to us, and we will replace it or provide a satisfactory solution.

Please contact us first and send us pictures or videos to verify. If the cargo is lost or the battery is damaged to the point where it cannot be used (or poses a high safety risk), we will coordinate with the buyer to resend, replace, or refund the product cost. If the buyer returns the cells, the buyer pays the shipping costs.

1. Issues occurring during or after the assembly process, such as a protection board connected incorrectly causing battery damage, charger failure, assembly errors, or unbalanced assembly.
2. Damage caused by battery bulging, welding, or charging a battery pack without a protective BMS.

Tips:
* These products are prototype cells without a protection board; you need to purchase a matching BMS. Please consult us for details.
* Please consider these terms before placing an order. Placing an order indicates agreement to these terms. Thank you for your cooperation!