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Description

Hohm Tech SCHOOL⁴A Smart 4-Bay Charger

The Professor of Charging — 100% Autonomous. Zero Confusion.


🎁 What You Get:

  • 1x Hohm SCHOOL⁴A Universal Battery Charger

  • Compatible with: 18650, 20700, 21700, 26650 & more (up to 73mm)

  • Supports: Li-ion cells (3.6V / 3.7V only)
    USB-C Fast Charging Input
    Same-Day Shipping
    30-Day Money Back Guarantee


⚡ Smart. Safe. Seriously Simple.

No screens. No settings. No user errors.
The Hohm SCHOOL⁴A delivers a fully autonomous charging experience using Hohm Tech’s advanced 3-Tier BLD (Battery Length Detection) system. Whether you're charging one or four cells, this charger intelligently adjusts the output rate per slot—0.5A, 1A, or 2A per bay (up to a 4A combined total). Just plug it in, insert your batteries, and let it do the rest.


🧠 Intelligent Charging Features:

  • BLD³ System — Automatically senses battery size and adjusts charge rate

  • Low Voltage Activation — Revives deeply discharged batteries down to 1.95V

  • IPR (Input Power Regulator) — Stabilizes voltage to protect both the charger and your USB-C power source

  • LED Status Indicators — Clear red/green lights show charge progress and slot status

  • Universal Compatibility — Works with all standard Li-ion sizes from 30mm to 73mm

  • PCB/PCM Safe — Fully supports protected and unprotected cells


🔐 Built-In Protection:

  • Overcharge Protection

  • Reverse Polarity Detection

  • Short Circuit Prevention

  • Incorrect Battery Type Detection

  • Non-ABS Fire-Retardant Housing

This is charging made foolproof—with all the safety features you expect and more.


🚀 Performance You Can Count On

The SCHOOL⁴A was born from 18 months of engineering and field testing, designed to eliminate guesswork and prevent common mistakes made with traditional chargers. It doesn’t just charge—it protects, preserves, and extends the life of your Li-ion batteries with unmatched precision.

Total Output: 4A across 4 slots
Charging Input: USB-C (modern, fast, and stable)
Battery Types Supported: 3.6V / 3.7V Lithium-Ion only


📋 Certifications:

Every unit is tested and certified to meet global safety and transport standards:
✅ CE • ✅ ROHS • ✅ FCC • ✅ UN38.3 (Air/Sea Safe)
Backed by Hohm Tech’s industry-leading Product Liability Insurance (PLI) for your peace of mind.


⚠️ Battery Safety Reminder:
Lithium-ion batteries are powerful tools that must be handled with care. Always follow manufacturer safety guidelines. If you’re unsure about usage, storage, or charging, consult a certified lithium-ion specialist. Safety is non-negotiable.


Product form

Hohm School 4 Slot 18650 Battery Charger: Fits All Battery Sizes

    Hohm Tech SCHOOL⁴A Smart 4-Bay Charger The Professor of Charging — 100% Autonomous. Zero Confusion. 🎁 What You Get: 1x... Read more

    $24.99 $19.49

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        Description

        Hohm Tech SCHOOL⁴A Smart 4-Bay Charger

        The Professor of Charging — 100% Autonomous. Zero Confusion.


        🎁 What You Get:

        • 1x Hohm SCHOOL⁴A Universal Battery Charger

        • Compatible with: 18650, 20700, 21700, 26650 & more (up to 73mm)

        • Supports: Li-ion cells (3.6V / 3.7V only)
          USB-C Fast Charging Input
          Same-Day Shipping
          30-Day Money Back Guarantee


        ⚡ Smart. Safe. Seriously Simple.

        No screens. No settings. No user errors.
        The Hohm SCHOOL⁴A delivers a fully autonomous charging experience using Hohm Tech’s advanced 3-Tier BLD (Battery Length Detection) system. Whether you're charging one or four cells, this charger intelligently adjusts the output rate per slot—0.5A, 1A, or 2A per bay (up to a 4A combined total). Just plug it in, insert your batteries, and let it do the rest.


        🧠 Intelligent Charging Features:

        • BLD³ System — Automatically senses battery size and adjusts charge rate

        • Low Voltage Activation — Revives deeply discharged batteries down to 1.95V

        • IPR (Input Power Regulator) — Stabilizes voltage to protect both the charger and your USB-C power source

        • LED Status Indicators — Clear red/green lights show charge progress and slot status

        • Universal Compatibility — Works with all standard Li-ion sizes from 30mm to 73mm

        • PCB/PCM Safe — Fully supports protected and unprotected cells


        🔐 Built-In Protection:

        • Overcharge Protection

        • Reverse Polarity Detection

        • Short Circuit Prevention

        • Incorrect Battery Type Detection

        • Non-ABS Fire-Retardant Housing

        This is charging made foolproof—with all the safety features you expect and more.


        🚀 Performance You Can Count On

        The SCHOOL⁴A was born from 18 months of engineering and field testing, designed to eliminate guesswork and prevent common mistakes made with traditional chargers. It doesn’t just charge—it protects, preserves, and extends the life of your Li-ion batteries with unmatched precision.

        Total Output: 4A across 4 slots
        Charging Input: USB-C (modern, fast, and stable)
        Battery Types Supported: 3.6V / 3.7V Lithium-Ion only


        📋 Certifications:

        Every unit is tested and certified to meet global safety and transport standards:
        ✅ CE • ✅ ROHS • ✅ FCC • ✅ UN38.3 (Air/Sea Safe)
        Backed by Hohm Tech’s industry-leading Product Liability Insurance (PLI) for your peace of mind.


        ⚠️ Battery Safety Reminder:
        Lithium-ion batteries are powerful tools that must be handled with care. Always follow manufacturer safety guidelines. If you’re unsure about usage, storage, or charging, consult a certified lithium-ion specialist. Safety is non-negotiable.


        🔋 Important Battery Saftey and User Information ⚠️

        Saftey FirstSaftey First

        Important Safety Warnings from 18650 Battery Partners

        Important Safety Warnings from 18650 Battery Partners

        Improper use or mishandling of lithium-ion batteries can result in FIRE, EXPLOSION, or THERMAL RUNAWAY, leading to serious injury, property damage, or death. All users must read and follow our complete safety guidelines before purchase or use.



        🔴 Critical Warning

        Never carry loose batteries in your pocket, purse, or bag. Contact with metal objects like keys or coins can cause a short circuit, potentially resulting in severe burns, fire, or explosion.
        ✅ Always store or transport batteries in a protective case or box.

        🔧 Intended Use

        Our lithium-ion cells are intended for integration into protected battery packs that include a Battery Management System (BMS) or Protection Circuit Board (PCB).
        ❌ They are not intended for standalone use or use in consumer devices such as e-cigarettes or vaporizers.

        🔴 Critical Warning

        Never carry loose batteries in your pocket, purse, or bag. Contact with metal objects like keys or coins can cause a short circuit, potentially resulting in severe burns, fire, or explosion.
        ✅ Always store or transport batteries in a protective case or box.

        🔧 Intended Use

        Our lithium-ion cells are intended for integration into protected battery packs that include a Battery Management System (BMS) or Protection Circuit Board (PCB).
        ❌ They are not intended for standalone use or use in consumer devices such as e-cigarettes or vaporizers.

        🔥 What is Thermal Runaway?

        Thermal runaway is a dangerous chain reaction in which a battery overheats uncontrollably, potentially leading to fire or explosion.

        • Overcharging, short circuits, physical damage, or exposure to high heat
          Do not use any battery that shows signs of damage, including:

        ⚠ Important Safety Warnings from 18650 Battery Partners

        Improper use or mishandling of lithium-ion batteries can result in FIRE, EXPLOSION, or THERMAL RUNAWAY, leading to serious injury, property damage, or death. All users must read and follow our complete safety guidelines before purchase or use.


        🔴 Critical Warning

        Never carry loose batteries in your pocket, purse, or bag. Contact with metal objects like keys or coins can cause a short circuit, potentially resulting in severe burns, fire, or explosion.
        ✅ Always store or transport batteries in a protective case or box.


        🔧 Intended Use

        Our lithium-ion cells are intended for integration into protected battery packs that include a Battery Management System (BMS) or Protection Circuit Board (PCB).
        ❌ They are not intended for standalone use or use in consumer devices such as e-cigarettes or vaporizers.


        🔥 What is Thermal Runaway?

        Thermal runaway is a dangerous chain reaction in which a battery overheats uncontrollably, potentially leading to fire or explosion.

        • Common Causes:
          Overcharging, short circuits, physical damage, or exposure to high heat

        • How to Prevent It:

          • Use a smart charger

          • Avoid impact or puncture

          • Store batteries in a cool, dry place


        📦 Storage & Transport

        • Always use protective cases or boxes for storage and transport.

        • Never store loose batteries in pockets, bags, or near metal objects.


        🕵 Inspection Guidelines

        Do not use any battery that shows signs of damage, including:

        • Torn or missing PVC wrapper

        • Damaged or missing terminal insulator

        • Dents, leaks, bulging, or corrosion

        These are signs of internal instability and may lead to failure or fire.


        ⚡ Charging Safety

        • Use only smart chargers rated for lithium-ion cells

        • Match the charger voltage with battery specs

        • Never overcharge, over-discharge, or leave batteries unattended during charging


        ⛔ Prohibited Actions

        Do not:

        • Short circuit

        • Modify or puncture

        • Crush or expose to liquid

        • Solder directly to the cell (spot welding only is allowed)


        🚨 Emergency Response

        If signs of thermal runaway occur (smoke, swelling, or excessive heat):

        1. Stop use immediately

        2. Move the battery to a non-flammable surface (e.g., concrete or sand)

        3. For fires, use a Class D fire extinguisher or sand — never use water


        📜 Legal Disclaimer

        18650 Battery Partners is not liable for any damage, injury, or loss resulting from improper use, handling, or failure to follow safety guidelines. Lithium-ion batteries must be handled with strict adherence to all recommended safety practices.


        🔄 Reseller Responsibilities

        Resellers must:

        • Clearly communicate all safety warnings to customers

        • Provide individual protective packaging for each battery

        • Never distribute loose or unprotected cells

        Some batteries are shipped in bulk packaging; appropriate storage cases must be provided at the point of sale.


        🧩 Product Compatibility & Assembly

        • Compatibility is the customer’s responsibility.

        • 18650 Battery Partners does not guarantee fit or function in any specific device or application.

        • We do not take responsibility for battery pack design, assembly, or safety.

        Proper cell matching, protection circuitry, and safe construction practices are essential. Customers and resellers assume full responsibility for the safe handling and distribution of all products.


        Li-Ion WarningsLi-Ion Warnings

        18650 Battery Partners - High-Drain Lithium-Ion Cell Overview

        The 18650 Battery Partners’ high-drain lithium-ion cell is designed to support devices requiring continuous high power without frequent battery changes. This cell offers a 3015mAh capacity with a continuous discharge rate (CDR) of 22.1A and has a cut-off limit of 3.2V or 80°C, whichever is reached first, at 31.5A. For electric vehicle (EV) and direct current (DC) motor applications, the cell can support pulse loads of 37.1A for 5 seconds on and 30 seconds off, within defined limits.

        Built with advanced NMC chemistry and utilizing high-purity materials, each cell undergoes rigorous quality checks. Testing and certification align with UN38.3, EN62133, IEC62133 2nd Edition, and UL1642 safety standards, including required documentation for MSDS, CE, ROHS, UN38.3, and transport certifications.

        These cells are designed to be charged at appropriate rates within manufacturer specifications. Testing processes assess cycle life, thermal stability, voltage consistency, and resistance to ensure safety and consistent performance.

        Note: 18650 Battery Partners distributes and tests these cells but does not manufacture them directly. All products meet internal and external quality requirements for performance and safety.

        Important Safety Information

        Lithium-ion cells can pose serious hazards if misused, including fire, burns, injury, or property damage. Please follow all safety guidelines below:

        • out of reach of children and pets.
          cells to fire, microwaves, ovens, or temperatures above 100°C (212°F).
          in pockets, bags, or on your body. Always use a protective case that prevents the cells from touching each other or metal objects.
          or carry them on your body, as objects or debris may cause short circuits.


        do not exceed the cell’s rated wattage and amperage. Using cells beyond their rated limits can lead to overheating or explosion.

        Inspect for dents, tears, punctures, corrosion, or damage to the outer wrap before each use.


        and remove them promptly when fully charged.

        Charge only to the specified voltage (typically 4.2V) and avoid discharging below the minimum voltage (typically 2.5V).

        or batteries of different brands or capacities.


        non-conductive barrier prevents cells from touching each other or device metal surfaces, except at designated contacts.

        For additional information on lithium-ion safety, you may research “18650 battery safety” online to understand proper handling and use.

        Your safety is our priority at 18650 Battery Partners.

        Every cell model has been tested and certified by UN38.3, EN62133, IEC62133 2nd Edition, and UL1642 accredited laboratories and testing facilities assigned by regulatory bodies.  This includes MSDS, CE, ROHS, UN38.3, IEC, PSE, Specifications, and Air/Sea Transport certifications.  We do not cut corners. We deliver what we promise… chart-topping performance, capacity, consistency, and safety.

         To expound on safety:

         • modified cathode tag consisting of higher purity aluminum is utilized to aid in lowering internal resistance
        • updated poly seal with refined bitumen is installed in every cell to ensure excess pressure is controlled

         * CAN BE CHARGED AT 4.43A. This is not a misprint. 4.43A as in FOUR POINT FOUR THREE-amp charging is possible, tested, proven, and approved within all strict safety protocols set by YongDeli New Energy.
        ** TESTING BEYOND TEMPERATURE. int’l cells utilize both static & dynamic testing that includes but not limited to: density loss, thermal distribution, volt drop limiters, cycle life retention, and temperature. These tests are imperative to achieve true cell performance, longevity, and overall quality.
        *** NOTICE: The makers do not not manufacture batteries. These are made for and licensed achieving requirements set forth.

         1 Density Loss Ratio
        2 Thermal Image Distribution
        3 Pulse Voltage Drop Limitation
        4 Cycle Life Retention
        5 Resistance Retentivity Pre|Post
        6 Pulse & Peak is applicable to Dynamic EV Systems ONLY and rated @ ≤5 SEC ON / ≥30 SEC OFF

          

        WARNING:  LI-ION CELLS HAVE INHERENT RISKS IF MISUSED OR MISHANDLED.   CELL CAN EXPLODE CAUSING SEVERE BURN INJURY, FATALITY, AND PROPERTY DAMAGE– READ BELOW THOROUGHLY –

         CELL = BATTERY

         KEEP OUT OF REACH of minors (at least 18 years of age) and pets.

        • DO NOT PUT IN FIRE, oven, microwave, or expose to anything over 100oC (212oF)
        • DO NOT  CARRY or store OUTSIDE of its protective packaging or a PROTECTIVE CELL CASE.  The protective cell case must PREVENT CELLS FROM TOUCHING ONE ANOTHER.  UNDER NO CIRCUMSTANCE  is a protective case to be put in a pocket, bag, purse, or on your body.  A protective case can be carried by hand in a controlled manner and/or stored where it is not subjected to movement or extreme temperatures.
        • DO NOT PUT IN POCKET, bag, purse, or on your body (applicable at all times and in all circumstances).  Pockets contain KEYS, COINS, OBJECTS, and/or DEBRIS that can short-circuit a cell (battery) that can result in an explosion.  The cell is to be stored in its protective packaging or a protective case that prevents cells from touching one another.  UNDER NO CIRCUMSTANCE ARE CELLS (batteries) TO BE PUT IN A POCKET, bag, purse, or on your body.  With cell(s) in a protective case, carry by hand or store where cell(s) are not subjected to movement.
        • DO NOT PUT A DEVICE WITH CELL(S) INSTALLED IN IT IN YOUR POCKET or ON YOUR BODY.  As unlikely as it may be, a device can malfunction and/or be affected by debris or object(s) in the pocket that can short-circuit a cell causing it to explode.  Additionally, removable-battery devices enable the cell(s) to move/shift inside a device which can subject cell(s) to condition(s) that put wear and tear on a cell’s protective label/wrap/skin barrier.  This can lead to a short-circuit and potential explosion.  Being in a pocket subjects the device (and cell(s)) to abrupt and jarring movements.  Carrying and using the device with hand(s) is proper.  ** we encourages to use a fire-retardant case/enclosure to carry device(s) with cell(s) installed inside it (applicable to device(s) with external and/or removable cell(s)). 
        • DO NOT USE IN A DEVICE THAT CAN EXCEED MAX CELL WATTAGE (W) or AMPERAGE (A) (listed on each cell and retail packaging).  Otherwise, this can overload a cell, causing it to explode.
        • DO NOT USE A LOWER RESISTANCE (Ω) # (listed on each cell and retail packaging).  Otherwise, this can overload the cell(s), causing it to explode.
        • DO NOT USE CELL WITH ANY DAMAGE TO ITS STRUCTURE OR OUTER PROTECTIVE LABEL (also called “WRAP”, “sleeve”, “skin”). Damage may include: dent(s), tear(s), nick(s), puncture(s), corrosion, or any other undisclosed abnormalities or damages.  Otherwise, a cell can short-circuit and explode.  ALWAYS INSPECT cell VISUALLY and by TOUCH to SEE/FEEL for damage BEFORE EACH USE.  ** SEE THE ILLUSTRATION BELOW AS A GUIDELINE. **
        • DO NOT LEAVE UNATTENDED WHILE CHARGING, & IMMEDIATELY REMOVE CELL(s) FROM CHARGER ONCE FULLY CHARGED to ensure it is not exposed to any potential charger malfunction such as overcharging which could damage the cell causing it to explode.
        • DO NOT CHARGE HIGHER THAN MAX CHARGE VOLTAGE (V) (typically 4.2Vor DISCHARGE BELOW MAX VOLTAGE CUT-OFF (V) (typically 2.5V).  Overcharging or over-discharging cell(s) can cause irreversible damage and cause it to explode.
        • DO NOT MIX WITH USED or DIFFERENT BATTERY TYPES. Differences in cell capacity can lead to one or more cell(s) being overcharged or over-discharged. 
        • IF USING A MULTI-CELL DEVICE, the device MUST HAVE A NON-CONDUCTIVE BARRIER (typically plastic) OR FITMENT that PREVENTS CELL(S) from TOUCHING THE SIDE(S) OF ONE ANOTHER OR ANY ADJACENT METAL except for the very center of top and bottom of the cell. Otherwise, cell(s) could short-circuit and explode.
        • ALWAYS REPLACE CELL when capacity has decreased or within a maximum of 12 months of use (whichever occurs first) when used in a device that allows cell(s) to be changed/removed.  Cell degradation and wear incurred from repeated installation/removal can negatively impact cell integrity and subject it to conditions that can cause it to be short-circuited and explode.
        • ALWAYS charge, connect, and operate cell(s) within their capabilities as listed on each cell, packaging, and all product detail pages, while adhering to the device’s user manual.
        • COMPLETELY READ and follow the WARNING section listed on each cell, packaging, and here, in its entirety.
        • Understand the importance of consistently taking safety precautions and using Li-ion cells properly.  Cell advocates recycling and replacing any damaged Li-ion cell/battery. As a tool to find your LOCAL RECYCLE CENTER. 
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