结论：电量放着掉，要分清是电路在耗还是电池自己在掉

使用者反馈「放了两周没用，电就没了」。这个现象有两个来源，需要分开看：

待机功耗是电路在耗电——控制器的待机电路、BMS 的监测电路、显示模块、无线模块，即使关机也可能有部分电路保持工作。

自放电是电池自身的化学反应导致的电量损失，与外部电路无关。

两者的量级和应对方式不同。待机功耗可以通过设计降低，自放电只能通过选型和存放条件控制。

待机功耗的来源

来源 说明 可否降低
BMS 监测电路 持续监测电压温度 可优化，但不能完全关闭
控制器待机 等待唤醒信号 可通过低功耗设计降低
显示与指示灯 部分产品关机后仍有指示 可以关闭
无线模块 蓝牙等保持连接或广播 可设置休眠
电源转换损耗 稳压电路自身消耗 可通过选型改善
漏电流 元件老化或受潮导致 属于异常，应排查

最后一行是异常情况。 如果待机电流明显高于设计值，要怀疑是否存在漏电——受潮、元件失效、或者线路绝缘问题。这类问题除了耗电，还可能有安全隐患。

自放电的影响因素

自放电速率主要受三个因素影响：

温度。 温度越高自放电越快。夏季存放在高温环境下，电量损失明显更快。

荷电状态。 不同荷电状态下的自放电速率不同，而且长期处于满电或空电状态对电池本身也不利。

电池状态。 老化的电池自放电通常比新电池快，内部微短路会显著加速自放电。

如果某个电池的自放电明显快于同批次其他电池，要怀疑内部缺陷，这可能是安全隐患的早期信号。

测量方法

待机电流测量。 在关机状态下测量电池输出端的电流。要注意的是有些系统在关机后会经历几个阶段（先进入休眠、一段时间后进入深度休眠），所以应当测量一段时间的曲线而不是单点。

自放电测量。 需要把电池与电路完全断开，充到规定荷电状态后静置，定期测量开路电压或容量。这个试验周期较长。

综合的电量保持测试。 整机在关机状态下静置，定期记录电量。这个数据最贴近使用者的实际体验，但混合了两个因素。

建议三种都做：综合测试反映实际体验，分项测试说明原因。只做综合测试，发现电量掉得快也不知道该改哪里。

对使用者的实际影响

几种典型场景：

短期不用。 一两周不用，损失的电量通常可接受，但如果待机功耗偏高，可能导致下次使用时电量不足。

长期存放。 几个月不用（比如季节性使用），电量可能降到很低。如果降到过放保护的阈值以下，电池可能进入无法唤醒的状态，需要专门的激活流程，甚至无法恢复。

备用电池。 配备备用电池的产品，备用电池长期不用，同样面临这个问题。

最后一点在售后中出现过。 使用者备了一块电池，半年后拿出来发现完全充不进电，这通常就是过放导致的。

设计与说明上的应对

设计方向： 降低待机功耗，尤其是深度休眠状态；设置低电量时自动切断非必要电路；提供物理断电开关或拔插接口，长期存放时彻底断开；在电量降到临界前给出提醒（如果产品有联网能力）。

说明书要给出的： 长期存放前充到什么程度；存放环境的温度建议；多久需要补充充电一次；如果长期未用，使用前该怎么检查。

「多久补一次电」这条要有数据依据。 根据实测的电量保持数据，给出一个安全的间隔，而不是笼统写「定期充电」。

与保修的关系

因过放导致的电池损坏，责任归属常有争议。企业的立场通常是使用不当，使用者的立场是产品放着就坏了。

减少争议的办法是把话说在前面：说明书明确写出存放要求和补电间隔；在产品上做永久标识；交付时口头告知。做到这几点，责任边界就清楚了。

更积极的做法是从设计上降低发生概率——彻底断电的开关、低电量提醒、更低的待机功耗，这些都能减少此类售后。

运输与仓储环节

产品从出厂到到达使用者手里，中间可能经历数周甚至数月。这段时间电量在持续下降，而且仓储环境的温度未必受控。

建议在出厂设定一个合适的荷电状态，既满足运输安全要求，又能保证到达使用者手中时仍有足够电量。这个值要基于实测的电量保持数据和典型的流通周期来定。

经销商环节也值得提示：库存产品需要定期补电，否则积压时间长的产品可能出现电池问题。

与保修条款的衔接

因长期存放导致的电池过放损坏，是否在保修范围内，应当在保修条款里说清楚，并与说明书的存放要求对应。

条款与说明书要一致：说明书要求每两个月补一次电，保修条款就应当以此为依据。两处说法不一致时，争议中通常对企业不利。

用户可见的电量指示

电量指示的准确性影响使用者对续航的判断。长期存放后，电量指示可能不准——电池的开路电压与实际可用容量之间的关系会因为静置而变化。

建议在长期存放后建议使用者先完整充放一次，让 BMS 重新校准电量估算。说明书里给出这个提示，能减少「显示有电但很快没电」这类反馈。

数据用于产品改进

待机功耗的测量数据可以直接指导改进：把各个模块的贡献分别测出来，就知道优化哪个模块收益最大。

实务上常见的发现是，某个看起来不起眼的模块占了待机功耗的大部分，比如一个常亮的指示灯或者一个未进入休眠的无线模块。这类问题改动成本很低，效果却明显。

我们的做法

做这类测试时，我们会分别测待机电流和整机电量保持，并记录测试期间的环境温度。温度不记录，不同批次的数据就没有可比性。

对于面向季节性使用或者有备用电池的产品，建议把长期存放的电量保持作为单独项目，按实际可能的存放时长设定试验周期，数据用于制定存放建议。

有需要可以把电气方案和使用场景发过来一起定测试方案，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见电动轮椅检测与代步车检测，标准信息见标准查询。

English version

Conclusion. When a user reports that a chair left unused for two weeks has lost its charge, two distinct causes are at work. Standby consumption is the circuitry drawing current: the controller's standby circuit, the BMS monitoring circuit, display modules and wireless modules may all remain partly active even when the chair is switched off. Self-discharge is capacity lost through the battery's own internal chemistry, independent of external circuitry. The two differ in magnitude and in remedy: standby consumption can be reduced by design, while self-discharge is controlled through cell selection and storage conditions.

Sources of standby consumption. BMS monitoring runs continuously and can be optimised but not switched off entirely. Controller standby waits for a wake signal and can be reduced through low-power design. Displays and indicators that remain lit after shutdown can simply be turned off. Wireless modules maintaining connection or advertising can be put to sleep. Regulator circuits consume some current themselves, improvable through component selection. And leakage current from aged or damp components is abnormal and should be investigated, since beyond consuming charge it may indicate a safety issue.

Factors affecting self-discharge. Temperature, with higher temperatures accelerating loss, so summer storage in a hot place loses charge noticeably faster. State of charge, since discharge rates differ and prolonged storage at full or empty is also harmful to the cell. And cell condition, since aged cells self-discharge faster and internal micro-shorts accelerate it markedly. A cell self-discharging noticeably faster than others from the same batch should raise suspicion of an internal defect, which can be an early safety signal.

Measurement. Standby current is measured at the battery output with the system switched off. Note that some systems pass through stages, entering sleep and then deep sleep after a period, so measure a curve over time rather than a single point. Self-discharge requires disconnecting the battery from the circuitry entirely, charging to a defined state and letting it stand while open-circuit voltage or capacity is measured periodically; this takes a long time. Overall charge retention is measured on the complete vehicle switched off, with charge recorded periodically, which best reflects user experience but combines both effects. Doing all three is worthwhile: the combined test reflects experience while the separate tests explain the cause. With only the combined test, rapid loss is observed without knowing what to change.

Practical impact on users. For short periods of a week or two, losses are usually acceptable, though high standby consumption may leave insufficient charge for the next use. For long storage over several months, such as seasonal use, charge may fall very low; if it drops below the over-discharge protection threshold the pack may become unwakeable, requiring a special activation procedure or proving unrecoverable. Spare batteries face the same issue, and this does appear in service: a user keeps a spare, finds six months later that it will not accept charge, and over-discharge is usually the reason.

Design and documentation responses. In design, reduce standby consumption particularly in deep sleep; disconnect non-essential circuits automatically at low charge; provide a physical isolating switch or removable connector for long storage; and warn before charge reaches a critical level where connectivity allows. In the instructions, state what charge level to store at, the recommended storage temperature range, how often to top up, and what to check before using after a long period. The top-up interval should rest on measured retention data rather than a vague instruction to charge periodically.

Relationship to warranty. Responsibility for a battery damaged by over-discharge is frequently disputed, with the manufacturer citing misuse and the user observing that the product failed while simply sitting. The way to reduce disputes is to state the position in advance: storage requirements and top-up intervals in the instructions, permanent marking on the product, and verbal explanation at handover. A more constructive approach is to reduce the probability by design, through a true isolating switch, low-charge warning and lower standby consumption.

How we handle it. We measure standby current and whole-vehicle charge retention separately and record ambient temperature throughout, because without temperature the data are not comparable between batches. For products used seasonally or supplied with a spare battery we suggest treating long-term retention as a distinct item, with the duration set from realistic storage periods and the data used to derive storage recommendations.

Send us the electrical design and use scenario and we will define the test approach. Phone or WeChat: +86 132 4819 8029.