This Dayi 21V lithium battery pack is a high-performance industrial replacement battery compatible with all Dayi cordless power tools, solving weak power, voltage drop, overheating and short endurance issues. Established in 2009, Jiangxi Huaxin Industry & Trade owns 6 production bases and large annual output with self-independent R&D and production capacity. Adopting Grade A+ 13005 cells and upgraded BMS system, it supports stable 3C/5C high-rate discharge and 800+ charge-discharge cycles. Certified with ISO9001, IATF16949, ROHS and CE, and equipped with 300+ patents, it cooperates with BYD and supports customized OEM/ODM services for construction, maintenance, garden work and cross-border export. Official website: http://www.huaxin-hairtools.com.
Product Basic Overview
This rechargeable Dayi 21V lithium battery pack has standardized complete product specifications with exclusive model and item numbers, suitable for domestic wholesale, retail, engineering procurement and cross-border export. Manufactured in the standardized production base of Fuzhou High-tech Zone, Jiangxi, relying on a 5,000㎡ factory area and 16,000㎡ construction area, it implements full-process standardized quality control with stable delivery and consistent quality. The battery shell is integrally injection-molded with thickened high-strength ABS engineering plastic, with fine matte anti-slip, wear-resistant, scratch-proof and impact-resistant treatment. With solid texture and stable structure, it effectively resists construction collision, high-altitude falling, dust and oil erosion without deformation, cracking or shell peeling under long-term high-intensity use. Adopting Dayi exclusive 5-series multi-parallel mature structure, it has two specifications: 1300mAh (3C) conventional rate and 2000mAh (5C) high rate, accurately matching the power supply demand of full-series Dayi tools. Featuring 18.5V nominal voltage and 21.0V full charge voltage, the discharge cut-off voltage is stably maintained at 13.75V-15.0V, with internal resistance ≤60mΩ, high cell consistency, zero false capacity and zero voltage difference. The voltage output is stable and continuous, avoiding sudden power failure and fluctuating power during construction. The optimized internal cell layout and heat dissipation structure effectively eliminate local high temperature, cell attenuation and power failure faults, greatly improving service life and working stability. The lightweight design balances firmness and drop resistance, reducing hand burden during long-term high-frequency operation, adapting to the working habits of domestic construction workers.
Performance Parameters & Protection FunctionsThe Dayi 21V lithium battery pack is available in 8 gradient capacity versions including 1.3Ah, 2.6Ah, 3.9Ah, 5.2Ah, 2Ah, 4Ah, 6Ah and 8Ah, fully covering household light maintenance, commercial batch construction and industrial heavy-load operation. Supporting dual 3C conventional discharge and 5C high-rate discharge modes, the standard discharge current is 0.5C-1C with strong peak discharge power and stable torque output, perfectly matching high-power Dayi tools such as impact wrenches, electric drills, angle grinders and pruning machines. Adopting constant current and constant voltage intelligent charging technology, it ensures uniform and stable charging, accurate cell protection, high charging conversion rate and low loss, effectively delaying cell aging and extending cycle life. With excellent wide-temperature adaptability, the charging temperature ranges from 0℃-45℃, discharge temperature from -20℃-60℃, and storage temperature from -10℃-30℃, adapting to complex environments such as high-temperature construction sites in summer, low-temperature outdoors in winter and humid closed workshops. The upgraded built-in intelligent BMS system provides six-fold intelligent protection against overheat, overvoltage, overcurrent, short circuit, overload and PTC risks, real-time monitoring cell temperature, current and voltage with intelligent power-off protection to eliminate hidden dangers such as bulging, short circuit, burnout and over-discharge. Equipped with 4-segment LED power indicator for clear remaining power display. The exclusive Dayi snap-in interface ensures stable plugging, sensitive contact and anti-loosening vibration resistance. The detachable dustproof filter at the air inlet regularly cleans sawdust and dust to ensure smooth heat dissipation. The integrated body without screen and foldable structure is sturdy, drop-resistant and wear-resistant, suitable for long-term high-frequency construction operation.
Applicable Crowds, Purposes & Scenarios
Applicable Crowds: Household DIY enthusiasts, domestic professional decoration workers, steel structure installation technicians, equipment maintenance personnel, garden greening construction workers, hardware store owners, project contractors, domestic engineering purchasers, cross-border foreign trade wholesalers, factory operation and maintenance staff and daily power tool users.
Applicable Purposes: Perfectly compatible with full-series Dayi 21V cordless drills, impact wrenches, impact drivers, angle grinders and garden trimmers. It supports screw disassembly, bolt tightening, steel drilling, profile cutting, plate polishing, garden pruning, equipment maintenance and mechanical assembly, meeting diverse demands including household daily repair, store retail stocking, batch construction, engineering supporting procurement and cross-border e-commerce inventory.
Applicable Scenarios: Widely used in home maintenance rooms, indoor decoration construction sites, steel structure installation sites, outdoor garden greening areas, factory maintenance workshops, building infrastructure sites, hardware warehouse storage, cross-border stocking warehouses and factory operation and maintenance scenarios.
This exclusive Dayi replacement lithium battery adapts to most domestic construction conditions. The lightweight ergonomic body greatly reduces hand fatigue during long working hours, perfectly suitable for household daily maintenance, commercial professional construction, outdoor engineering operation and bulk stocking, serving as the preferred replacement lithium battery for domestic power tools.
Certification, Packaging & Customization
This Dayi replacement lithium battery has passed authoritative certifications including CE, FCC, MA, CNAS, ROHS and REACH, complying with domestic quality inspection standards and global cross-border export specifications. Supported by ISO9001 quality management system, IATF16949 industrial certification and more than 300 independent patents, it features mature production technology, strict quality control and stable quality without compliance risks, suitable for engineering procurement, supermarket entry and foreign trade export. Each unit is packed with an independent high-quality color box and thickened carton reinforcement, shockproof, compression-resistant and moisture-proof, adapting to domestic logistics and ocean shipping. Standard packing quantity is 20 pieces per carton. With sufficient large-scale production capacity, the factory provides full OEM and ODM customization services, including laser logo engraving, customized packaging, parameter adjustment and private label production. Standard MOQ is 100 pieces, sample lead time 3-5 days, bulk order lead time 15-25 days, with 12-month official warranty. It supports domestic hardware channel distribution, engineering bulk procurement, cross-border export, enterprise gift matching and physical store retail, providing high-cost-performance and stable core lithium battery supply for domestic and foreign merchants.
This industrial lithium battery pack is a high-end lithium energy storage battery pack tailored for engineering construction, auto repair, garden maintenance, commercial operation and factory reserve, serving as a high-strength high-power energy storage battery for industrial operations. It fully integrates 9 core selling points of lithium batteries, solving industrial pain points of insufficient power, unstable voltage, short service life, poor safety and weak environmental adaptability of traditional batteries. Equipped with an upgraded smart protection battery BMS system, it resists high-current impact and provides full protection against electrical faults, avoiding battery burnout and shutdown during high-frequency industrial operation.
Adopting military-grade military-grade battery cells, it supports continuous output of high-current discharge battery and realizes full-working-condition constant voltage lithium battery operation, eliminating power drop of high-power tools. With long-cycle battery performance and outstanding low-attenuation industrial battery features, it maintains durability under high-intensity operation, reducing enterprise maintenance and replacement costs. Thanks to the wide-temperature industrial battery advantage, it works stably in harsh industrial environments such as high temperature, low temperature, humidity and dust with strong adaptability.
The lightweight industrial battery and integrated structure is lighter and more compact than traditional lead-acid batteries, convenient for handling, installation and debugging. It features ultra-low self-discharge, suitable for factory inventory reserve and construction site emergency backup. With full cross-border industrial battery compliance qualifications, it is a formalcompliant energy storage battery, ideal for foreign trade lithium battery and engineering energy storage battery cross-border sales and transportation.
It covers 108 industrial, commercial, engineering and emergency scenarios, fully compatible with industrial power tool batteries such as impact wrenches, electric drills and angle grinders to meet construction needs. It supports garden equipment, water pumps, high-pressure cleaners and disinfection sprayers for garden irrigation and environmental sanitation. It serves as an industrial backup power supply and construction equipment battery for construction site lighting, store emergency power and property maintenance. It adapts to auto repair, advertising spraying, exhibition temporary power supply, agriculture, animal husbandry, fishery, RV and ship power supply, as well as disaster rescue and pipe gallery inspection. It supports industrial customizable battery service and is the preferred professional industrial lithium battery, durable industrial battery and high-efficiency discharge battery for industrial and commercial fields.
Product Usage Instructions
New Dayi compatible lithium batteries are pre-charged with residual power. It is recommended to fully charge before formal use to fully activate Grade A+ cell activity, improve discharge efficiency and endurance stability, and extend overall cycle life. For long-term storage, complete a full charge and discharge cycle every two months to prevent cell dormancy, capacity attenuation and internal resistance increase. Store in dry, cool and ventilated places, away from high temperature, humidity and flammable materials. Only use the dedicated original 21V charger; mismatched chargers are strictly prohibited to avoid short circuit, overheating, cell damage and bulging caused by unmatched current and voltage. Charge in open, dry and well-ventilated environments; closed-space charging is forbidden. Cut off power timely after full charging to prevent long-term overcharging. Never short-circuit positive and negative poles with metal objects, immerse in water, drop violently, extrude, puncture or burn the battery. Non-professionals are not allowed to disassemble or modify the battery. Stop using immediately in case of abnormal heat, bulging, power failure, insufficient power and poor contact, cool down and contact after-sales support instead of self-repairing. Waste batteries shall be recycled in accordance with environmental protection regulations to avoid safety hazards and environmental pollution.
After-sales Policy
Please check the battery interface, size and compatible model carefully before ordering to ensure full matching with Dayi 21V power tools. This product enjoys 12-month official warranty. Free replacement service is available for non-human quality problems without water ingress and irregular operation within the warranty period. For non-artificial quality faults occurring within one month after order confirmation, the round-trip freight shall be undertaken by Jiangxi Huaxin Industry & Trade Co., Ltd.; after one month, the buyer shall bear all return and replacement freight. Natural capacity attenuation, normal wear, water damage, artificial breakage and unauthorized disassembly damage are not covered by the warranty. For non-quality returns caused by wrong purchase and personal mismatch, all transportation fees shall be borne by the buyer, and cash-on-delivery is not supported. All after-sales terms are transparent. Order placement means full recognition of the after-sales agreement, welcoming long-term bulk procurement and customized cooperation from domestic and foreign merchants.
CN
Registered trademarks (1) 
