DIY Assembly: DIY battery packs must have the cells balanced (same voltage) before assembly. Later, if you do not know how to assemble them or wrong assembly occurs, refunds cannot be accepted. Professionals detect voltage, resistance, and appearance before every shipment. We ensure the single battery is good when sent. Upon arrival, you can test the cells within 15 days. Beyond that, the cells are assumed to be in good working condition, and no returns or refunds are provided.

Return Policy: Batteries can only be returned if unused (electrodes intact, no welding, no wear, and appearance is good). The buyer is responsible for return shipping costs.

Warranty: Warranty period is 5 years from successful delivery. If the single battery capacity drops below 80% of the initial capacity, send test pictures or video to us for a replacement or solution.

Shipping Damage: If there is any missing or damaged item from shipping, contact us immediately with pictures or video. We will determine if a resend, replacement, or refund of product cost is necessary. Buyer covers return shipping if sending cells back.

Excluded Situations: We do not offer returns or refunds if:
1. Damage is caused during assembly processes (e.g., BMS protection board wired wrong, charger failure, unbalanced assembly).
2. Damage caused by user misuse, such as cell bulges/welded electrodes, or charging a battery pack without a BMS.

Tips: These products are prototype batteries without protection boards; you must purchase a matching one. Please consult us for assistance. Please consider these factors before placing orders. Placing an order implies agreement to these terms. Thank you for your cooperation!