带电池器械的电气安全考察点

结论：电池把几类风险集中到一个部件上

带电池的器械，安全考察的重点会集中到电池及其周边电路上。原因是电池同时具备几个特点：储存了相当的能量、能量释放可能很快、失效模式包括发热和燃烧、以及性能随使用衰减。

这几个特点叠加，使电池成为产品上风险密度较高的部件。 而康复辅具中电动产品的比例在上升，电池相关的考察也就越来越重要。

电池相关的风险

其中过充电和内部短路的后果最严重，可能导致热失控。所以保护措施要在这两项上做足。

保护的层次

电芯层面。 电芯本身的安全特性，包括安全阀、隔膜特性。

电池组层面。 电池管理电路的保护功能——过充、过放、过流、过温保护。

充电器层面。 充电控制、限压限流。

设备层面。 设备对电池状态的监测和响应。

结构层面。 电池仓的机械防护、防止挤压穿刺、防止反接。

多层保护是基本要求，单一层次的保护失效不应导致危险。验证时应当逐层确认，而不是只看电池组有保护就认为足够。

充电与保护的验证

充电特性验证。 实测充电电压、电流曲线，确认与电池规格匹配。

过充保护。 人为使充电控制失效，验证保护是否动作、动作阈值是否合适。

过放保护。 持续放电至保护动作，确认阈值和恢复行为。

过流与短路保护。 输出短路时的保护动作和响应时间。

温度保护。 高温和低温下的充电限制。低温充电对锂电池有害，应当有保护。

异常充电器。 使用不匹配的充电器时设备的行为。这对应实际中的误用场景。

反接保护。 可更换电池的产品，验证反接时的保护。

「低温禁止充电」这一项在北方地区使用的产品上很重要，因为冬季在室外或未供暖场所充电的情况会发生，而低温充电会损伤电池并增加后续风险。

使用条件下的验证

除了故障状态，正常使用中的一些条件也要验证：

高温环境下的性能与安全。 夏季车内、直晒环境。

低温环境下的容量。 冬季续航下降的幅度。

长期存放。 存放期间的自放电和过放电风险。

循环寿命。 充放电循环后的容量保持。

振动与冲击。 使用中的振动对电池连接的影响。

跌落。 整机跌落后电池及其固定是否完好。

「长期存放」这一项容易被忽略。 产品在仓库或使用者家中长期不用，电池可能因自放电进入过放状态而损坏，甚至在后续充电时产生风险。资料中应当给出长期存放的处理建议。

运输方面的要求

含锂电池的产品在运输上有专门要求，这影响样品送检和产品出货：

需要相应的运输测试报告。 送检和出口时可能需要。

包装要求。 符合相关的包装规定。

标识要求。 包装上的相关标识。

数量与配置限制。 不同运输方式的限制不同。

建议在项目早期就确认运输方面的要求，因为准备相关文件需要时间，临到出货才发现会耽误进度。送样检测时同样要注意，含电池的样品运输有额外手续。

资料与标识

产品资料中应当包含：

电池型号与规格；充电方法与限制（含温度限制）；充电器的配套要求——明确说明不能使用非配套充电器；电池的更换方法（如可更换）；长期存放的处理；电池寿命与更换判断；废弃处理的说明；以及相关的安全警示。

「不能使用非配套充电器」这一条要写得醒目，因为通用接口的产品，使用者很容易用手边的充电器，而参数不匹配可能造成过充。

电池老化的管理

电池容量会随循环次数和时间下降，这带来几个实际问题：

续航缩短。 使用者可能在半路没电，对依赖电动轮椅出行的人是实际风险。

电量指示失准。 老化后的电池，原有的电量估算算法可能不准。

内阻上升。 大电流输出能力下降，可能影响爬坡等工况。

建议给出电池更换的判断依据 ——比如容量降到某个比例时建议更换。含糊地说「电池是消耗品」对使用者没有帮助。

电池的选型与来源

电池是外购件，选型和供应商管理直接影响产品安全：

电芯的安全数据。 要求供方提供安全测试报告。

电池组的保护电路。 确认保护功能齐全、阈值合适。

一致性。 多节电芯串并联时，一致性影响使用中的均衡和寿命。

供应商变更。 更换电池供应商属于重大变更，应当重新验证。

批次追溯。 电池应当可追溯到批次，便于出现问题时定位。

入厂检验。 对关键参数做入厂检验，而不是完全依赖供方声明。

「一致性」在多节电池组中影响很大。 单节电芯性能差异会导致使用中某些电芯过充或过放，加速老化甚至引发风险。

与整机的配合

电池不是孤立的部件，它与整机的配合要考察：

安装固定。 振动和冲击下电池不应移位，连接不应松动。

散热。 电池仓的散热条件是否满足电池的工作温度要求。

防水防尘。 电池仓的防护等级要与使用环境匹配。

接插件。 反复插拔的可靠性、接触电阻。

电量指示。 与实际容量的对应关系。

电池仓的散热在大功率产品上是实际问题 ——电池在大电流放电时发热，如果电池仓密闭且无散热设计，温度可能超出电池的允许范围。

我们的做法

做带电池产品的电气安全测试时，我们会把保护功能的实际动作作为验证重点，人为制造过充、过放、短路、高低温条件，看保护是否真的动作。 核对设计文件说有保护，与实测保护确实动作，是两回事。

另外，低温充电保护和长期存放后的行为，是我们建议加做的两项——它们对应的是实际使用中会发生但常规清单里没有的场景。

如果你有带电池的产品需要安排测试，想先理清电池相关的项目，可以把电池规格和电路资料发过来一起讨论，或者直接联系：132 4819 8029。能力范围见服务介绍，流程见检测流程，更多内容见知识库。

English version

Conclusion. In battery-powered equipment, safety assessment concentrates on the battery and its surrounding circuitry, because a battery combines several characteristics: it stores substantial energy, that energy can be released quickly, its failure modes include heating and fire, and its performance declines with use. Together these make the battery one of the highest risk-density components in a product. As the proportion of powered rehabilitation products grows, battery assessment matters increasingly.

Battery-related risks. Overcharge arises from charge control failure. Overdischarge arises from protection circuit failure or prolonged storage. Overcurrent arises from short circuit or abnormal load. Overheating arises from high ambient temperature, high current or inadequate cooling. Mechanical damage arises from crushing, puncture or dropping. Internal short circuit arises from manufacturing defects or ageing. Reverse connection arises from incorrect installation. And ageing failure appears as capacity loss and rising internal resistance. Overcharge and internal short circuit carry the most serious consequences, potentially leading to thermal runaway, so protection must be thorough on both.

Layers of protection. At cell level, the cell's own safety features including vents and separator characteristics. At pack level, battery management protection against overcharge, overdischarge, overcurrent and overtemperature. At charger level, charge control with voltage and current limiting. At equipment level, monitoring of battery state and response to it. And at structural level, mechanical protection of the battery compartment against crushing and puncture and against reverse connection. Multiple layers are a basic requirement, and failure of any single layer should not produce a hazard. Verify layer by layer rather than assuming that pack-level protection suffices.

Verifying charging and protection. Verify charging characteristics by measuring the voltage and current profile and confirming they match the cell specification. Verify overcharge protection by deliberately disabling charge control and confirming that protection operates at an appropriate threshold. Verify overdischarge protection by discharging until protection operates, confirming the threshold and the recovery behaviour. Verify overcurrent and short circuit protection for operation and response time. Verify temperature protection, including charging restrictions at high and low temperature; low-temperature charging damages lithium cells and should be prevented. Verify behaviour with a mismatched charger, which corresponds to real misuse. And verify reverse connection protection where batteries are user-replaceable. Prohibition of low-temperature charging matters particularly for products used in cold regions, because charging outdoors or in unheated spaces does happen in winter, and it damages the cell and raises subsequent risk.

Verification under use conditions. Beyond fault conditions, certain normal conditions need verifying. Performance and safety at high ambient temperature, as in a car in summer or in direct sun. Capacity at low temperature, quantifying the winter range reduction. Prolonged storage, covering self-discharge and overdischarge risk. Cycle life, covering capacity retention after charge-discharge cycling. Vibration and shock, covering the effect on battery connections. And drop testing, confirming that battery and its mounting survive. Prolonged storage is easily overlooked: a product left unused in a warehouse or a user's home may self-discharge into an overdischarged state, damaging the cell and potentially creating risk on subsequent charging. Give guidance for long-term storage in the documentation.

Transport requirements. Products containing lithium batteries face specific transport requirements affecting both sample shipment and product distribution. Corresponding transport test reports may be needed for submission and export. Packaging must meet the relevant provisions. Packages must carry the relevant markings. And quantity and configuration limits differ by mode of transport. Confirm transport requirements early in the project, since preparing the documentation takes time and discovering the need at shipment delays matters. The same applies to sending samples for testing, since battery-containing samples carry additional formalities.

Documentation and marking. Include the battery type and specification; charging method and limitations including temperature; charger compatibility requirements, stating explicitly that non-supplied chargers must not be used; battery replacement method where replaceable; handling for long-term storage; battery life and how to judge replacement; disposal instructions; and the relevant safety warnings. Make the charger warning conspicuous, because products with common connectors invite users to reach for whatever charger is at hand, and mismatched parameters can overcharge.

Managing battery ageing. Capacity falls with cycles and time, which creates practical problems. Range shortens, and running out mid-journey is a real risk for someone dependent on a powered chair. State-of-charge indication loses accuracy, since the original estimation algorithm may not suit an aged pack. And internal resistance rises, reducing high-current capability and affecting conditions such as climbing. Give a basis for judging replacement, such as a capacity threshold; stating merely that the battery is a consumable helps the user not at all.

How we handle it. For battery-powered products we concentrate verification on whether protective functions actually operate, creating overcharge, overdischarge, short circuit and temperature extremes deliberately and observing the response. Design documentation stating that protection exists and measurement showing that it operates are two different things. We also suggest adding low-temperature charge protection and post-storage behaviour, both corresponding to real-world situations absent from routine lists.

Send us the battery specification and circuit documentation and we will scope the battery-related items. Phone or WeChat: +86 132 4819 8029.