Medical Battery Selection Guide
Selecting a medical ventilator battery pack requires more than comparing voltage and capacity. The battery must support the ventilator's electrical load, required backup time, charging system, physical structure, communication interface, operating environment, and applicable safety requirements.
Quick Answer
A suitable ventilator battery should match the device's required voltage, continuous and peak current, target runtime, charging voltage, connector, dimensions, and communication protocol. It should also include an appropriately designed battery management system and be validated as part of the complete ventilator power system. A battery should never be selected using amp-hour capacity alone.
Ventilators may be used in intensive care units, ambulances, emergency stations, patient transport, home healthcare, and other environments where a stable power supply is essential. Each application creates different requirements for battery weight, runtime, temperature tolerance, charging speed, replaceability, and system monitoring.
JGNE develops custom ventilator battery solutions for different voltage, capacity, structural, connector, and operating requirements. This guide explains the main technical factors equipment manufacturers and professional buyers should evaluate before starting a battery project.
The first step is to obtain the ventilator's complete power specification. Two batteries with the same nominal voltage and capacity may still behave differently because of their discharge capability, voltage curve, BMS settings, connector design, and communication functions.
Confirm the following information before selecting a battery:
Required nominal voltage and acceptable voltage range
Average operating power in watts
Continuous operating current and peak current
Required backup or transport runtime
Battery charging voltage and charging current
Available battery compartment dimensions
Connector type and cable configuration
Required communication protocol
Operating and storage temperature range
Applicable device, market, transport, and safety requirements
Voltage compatibility is particularly important. A battery with an incorrect voltage range may prevent the ventilator from starting, trigger a low-voltage alarm, interfere with charging, or cause the BMS to disconnect earlier than expected. The battery, charger, ventilator power input, and monitoring system must therefore be evaluated together.
Amp-hours alone do not provide a reliable comparison when battery voltages differ. Watt-hours provide a clearer indication of the battery's nominal stored energy.
Nominal Battery Energy
Watt-Hours (Wh) = Nominal Voltage (V) × Capacity (Ah)
A preliminary runtime estimate can then be calculated using the ventilator's average power consumption:
Estimated Runtime
Runtime (hours) = Battery Energy (Wh) × Usable Efficiency ÷ Average Device Power (W)
For example, if a battery stores 100Wh, the estimated usable efficiency is 85%, and the ventilator consumes an average of 20W, the preliminary runtime estimate would be:
100Wh × 0.85 ÷ 20W = approximately 4.25 hours
Important: This calculation is only a preliminary engineering estimate. Actual runtime can change with ventilator mode, humidifiers, heaters, displays, alarms, wireless modules, ambient temperature, battery age, discharge rate, conversion losses, and the BMS cutoff point. Final runtime must be confirmed through testing with the complete device.
A portable ventilator battery and a hospital backup battery may require different design priorities. The intended operating environment should be defined before the battery structure and cell configuration are finalized.
| Application | Main Battery Priorities | Questions to Confirm |
|---|---|---|
| Portable ventilator | Low weight, compact size, usable runtime, clear state-of-charge information | How much weight can the device carry? Can the battery be replaced without tools? |
| ICU or hospital ventilator | Backup reliability, charging management, monitoring, alarm integration and redundancy | How will the ventilator respond when AC power is lost or the battery reaches its cutoff point? |
| Ambulance or emergency transport | Vibration resistance, secure connectors, temperature tolerance and rapid replacement | What vibration, shock and temperature conditions will occur during transport? |
| Home healthcare | Simple charging, clear indicators, storage life, dependable connectors and user-friendly replacement | Will the battery be handled by trained personnel, a caregiver or the device user? |
Hot-swappable batteries, dual-battery redundancy, or external backup packs can improve power continuity only when the ventilator has been specifically designed and validated to support those functions. They should not be added based on battery specifications alone.
Lithium iron phosphate and NCM lithium-ion cells can both be used in professional battery systems, but their electrical characteristics and design tradeoffs differ. The appropriate choice depends on the ventilator's voltage, energy, weight, size, cycle-life, discharge, and environmental requirements.
| Consideration | LiFePO4 | NCM Lithium-Ion |
|---|---|---|
| Nominal cell voltage | Typically around 3.2V | Typically around 3.6–3.7V |
| Typical design strength | Thermal stability and cycle-life potential | Higher energy in a smaller or lighter pack |
| Pack impact | May require a larger structure for the same energy target | Can support compact designs but still requires appropriate protection and thermal evaluation |
| Selection basis | Use verified cell data, pack-level testing and complete device requirements rather than chemistry name alone. | |
Series connections determine battery voltage, while parallel connections increase capacity and current capability. The cell arrangement must also account for balancing, thermal distribution, manufacturing consistency, enclosure space, serviceability, and fault protection.
The battery management system is a central part of a ventilator battery pack. It should be designed around the selected cells, electrical load, charger, environmental conditions, and the ventilator's power-management logic.
Electrical Protection
Overcharge, over-discharge, overcurrent and short-circuit protection.
Temperature Monitoring
Charge and discharge control based on verified cell and pack temperature limits.
Cell Management
Cell-voltage monitoring and balancing for multi-cell battery packs.
System Communication
State-of-charge, temperature, fault and remaining-runtime data when required by the device.
If the ventilator displays remaining battery time, the battery and device algorithms must be evaluated together. State-of-charge estimation can be affected by load changes, temperature, battery aging, calibration, and voltage characteristics. A simple voltage measurement may not provide sufficiently accurate runtime information for every design.
Electrical compatibility is only one part of the project. The battery enclosure, connector, cable outlet, mounting structure, sealing, and thermal design must fit the ventilator and its intended environment.
Dimensions: Confirm the maximum length, width, height and acceptable dimensional tolerances.
Weight: Portable and transport ventilators may have strict total device-weight limits.
Connector: Prevent incorrect insertion, accidental disconnection and inadequate current capacity.
Enclosure: Consider impact, cleaning procedures, moisture exposure and mounting requirements.
Temperature: Define separate charging, discharging and storage temperature ranges.
Transport conditions: Evaluate shock, vibration and connector retention for ambulance or mobile use.
Charging accessories must also be matched to the battery and device. The FDA's medical-device charging guidance advises using the charging accessories provided by the device manufacturer and inspecting devices and accessories for damage. A custom battery project should therefore define the charger, charging profile, connector, thermal limits, and user instructions as parts of one power system.
Battery testing and complete medical-device compliance are related but different responsibilities. Passing a battery test does not automatically make the complete ventilator compliant for every country or intended use.
| Reference | General Relevance | Important Limitation |
|---|---|---|
| IEC 62133-2 | Safety requirements and tests for portable sealed secondary lithium cells and batteries. | It is not, by itself, approval of the complete ventilator. |
| UN Manual of Tests and Criteria, Subsection 38.3 | Transport qualification testing for lithium cells and batteries. | UN 38.3 is a transport requirement, not a medical-device certification. |
| IEC 60601-1 | General requirements concerning basic safety and essential performance of medical electrical equipment. | Applicable collateral or particular standards may also be required for the final device. |
The required test plan should be determined by the ventilator manufacturer, qualified compliance specialists, target-market requirements, intended use, device classification, and complete system design. Only standards, certificates and test results that apply to the specific cell, pack and final product should be stated in product documentation.
JGNE currently lists the following reference configurations for ventilator battery projects. These values can be used as an initial reference, but final specifications must be matched to the customer's device and validated through project-specific testing.
| Reference Configuration | Nominal Energy | Charge Voltage | Listed Working Current | Weight | Size |
|---|---|---|---|---|---|
| 12.8V 7.6Ah | Approximately 97.3Wh | 14.4 ± 0.15V | 10A | 915 ± 50g | 151 × 65 × 93mm |
| 32V 16Ah | Approximately 512Wh | 36.0 ± 0.2V | ≤3A | 4.6 ± 0.2kg | 141 × 207 × 123mm |
Buyers requiring a different voltage, capacity, enclosure, connector, BMS setting or communication function can discuss a project through JGNE's custom battery solutions.
Providing complete project information early helps reduce repeated revisions and allows the battery supplier to evaluate electrical, structural, thermal and testing requirements more accurately.
Ventilator input-voltage range and power specification
Average, continuous and peak current requirements
Required backup runtime under defined operating conditions
Charging voltage, current and charger information
Maximum battery dimensions and weight
Connector, wire length and pin definition
Communication protocol and required data fields
Charging, discharging and storage temperature ranges
Expected annual quantity and project schedule
Target markets, applicable standards and required documentation
Runtime depends on usable battery energy, ventilator power consumption, operating mode, accessories, temperature, battery age and system losses. Watt-hours divided by average device power can provide an initial estimate, but complete-device testing is required for a reliable runtime specification.
There is no universal capacity. The required watt-hours must be calculated from the ventilator's average power and target operating time, then adjusted for conversion losses, cutoff limits, temperature, aging and an appropriate engineering margin.
Neither chemistry is automatically best for every ventilator. LiFePO4 may be preferred when thermal stability and cycle-life potential are priorities, while NCM may suit applications requiring higher energy in a smaller or lighter structure. The final choice should be based on complete pack and device requirements.
A consumer power bank should not be treated as a ventilator power source unless the ventilator manufacturer has specifically approved and validated that configuration. Voltage, current, connector, communication, alarms, charging and power-transfer behavior must all be compatible.
A typical design may include overcharge, over-discharge, overcurrent, short-circuit and temperature protection, along with cell monitoring and balancing. Exact thresholds must be designed around the cells, charger, device load and intended operating environment.
No. UN 38.3 relates to lithium-cell and battery transport testing. It does not replace the safety, performance, risk-management or regulatory evaluation required for the finished medical device.
Send JGNE your voltage, capacity, current, runtime, dimensions, connector, communication and operating-environment requirements. Our team can evaluate a battery solution for your specific equipment project.
Discuss Your Battery RequirementsTechnical note: This article provides general battery-selection information for equipment manufacturers and professional buyers. Final battery specifications, runtime, safety functions and compliance requirements must be verified for the complete ventilator and its intended use.
