锂电网讯：2017年4月份，有部分Bolt EV的动力电池被报道出问题：“2017 Chevy Bolt EV battery may fail due to faulty cell; new pack needed for a few GM electric cars”，现在进一步扩大了，事情变得有些大条了。
部分2017年型号的Bolt EV电芯出现故障，当这个故障发生的时候，可能会导致车辆瞬间失去动力，没办法有效驱动，在高速道路上，这个事情可能会非常危险。这里有几点值得考虑：
部分电芯的衰减比较快
部分电芯在后期会突然跳水
采取措施：通用汽车一直在通过其OnStar 的车辆网程序监控这个问题，通过车辆网收集电池的实时数据和BMS计算出来的电池的健康状况，现在的问题是，车联网本身追踪也不能完全覆盖所有的潜在失效，对于通用来说，Bolt的部分车型是个大问题。
有些广告要给拿出来比一比，在某些情况下，非预设性的诊断覆盖的东西，车联网没办法。
如下图所示，这是车主在车辆论坛里面吐槽
I've had the car for about 2 months now (Purchased 9/30) and today while driving on the freeway home I got a message saying Loss of Propulsion. I noticed that the car was only allowing around 30kwh of power to be discharged even when I mash the throttle down. I exit the freeway and proceed to try to make it home thinking I'd be able to make it as it's about a mile or so down the road. I come to a complete halt at a stop light and proceed to accelerate normally when the light turns green and I noticed the limit on battery discharging again and hit a max speed of around 45 miles an hour.
Stop for another red light and this time it is a big hill so I tried to accelerate as hard as possible to make it up the hill and I make it to about 30mph before the screen starts throwing up error messages and I notice my battery level go from around 40 miles(25% battery) down to 29 miles left and into the orange and then rapidly declining to 0 followed by more error messages of battery is drained and I am now stuck on the side of the road.
With 0 miles left and no drive to the wheels I do my best to pull over to the side and use OnStar to call for assistance. They call a tow truck which took about an hour to get there and now the car is sitting at the dealer because service isn't open. I sure hope it is dealt with quickly and a rental car provided.
Notes: Car was manufactured in August 2017 so if it is a battery failure that is certainly not a good sign for everyone with bolts older than that. Torontonian69 likes this.
从以上的现象来看，这个N2.1系列的电芯，反应还是真奇怪，一放电本身的特性就出现大问题，触发BMS的故障，等恢复一加负载又跳水。这下损失可不小呢
When a cell "fails", its voltage tends to drop off very quickly, especially compared to other cells. Once the system detects the voltage of ANY SINGLE cell group is below minimum, it shuts down to protect the cells from over discharge. Obviously, if the battery is at 50% SOC and then suddenly a single cell drops to Vmin, then that cell is already damaged. This is why you get no warning. The new software must be more sensitive to detecting this. This is the equivalent of your phone shutting down during heavy use. I recommend anyone covered by this recall run your battery DOWN to 10% to maximize the chance of finding this fault. Staying at 90-100% SOC is not going to help the battery, but rather mask this problem.
电动汽车产业里面，这大概是第一个因为电芯问题，导致的召回，往前走，步步惊心，如履薄冰。成本还要降呢
根据“gmauthority.com”的消息，现在针对Bolt EV要启动传统汽车企业规模较大的一次OTA。电芯有问题，靠软件来弥补，也会成为未来的常态。
General Motors has officially responded to reports of isolated battery cell failure in 2017 Chevrolet Bolt EV models. In response to the possible issue, the automaker will roll out a software update for Bolt EV that dealerships will perform free of charge.
GM told InsideEVs that the recall is not a safety recall, but asked that all owners participate in the software update. Some owners have reported battery cell failure that leaves the Bolt EV without drive power.
After analyzing OnStar data, GM noted the issue seems isolated to very early production units of Bolt EV. The automaker will continue to comb through its data and notify owners who may be at risk for battery cell failure.
The software update will introduce “additional warnings if a battery cell low voltage condition occurs, which could cause the vehicle to reduce or lose propulsion.” Owners will see an indicator light if the battery is at risk of cell failure.
The update will not fix bad battery cells. Additionally, starting at the end of this month, Chevrolet and GM will begin pushing over-the-air software updates to the Bolt EV. It will make the Bolt EV the first vehicle from GM to make use of a vehicle’s internet connection for seamless updates without having to visit a dealership.
论坛里面也发送相关的信息到了车主了：
Just got an email from GM titled “2017 Bolt EV Software Updates” and providing instructions for owner-initiated updates. Not going to reiterate the email here, but here is a like to the instructions: http://gmrecall.xert.net/publicimage...uctions_F2.pdf
这正好GM的SuSanta Sarkar和James Forsmark发表了《汽车电子自动化软件更新OTA系统工程》，对于汽车电子来说，这将成为未来电动汽车厂家的标准配置，应对未来发生的问题。
汽车电子系统传统上被设计为嵌入式分布式系统，主要在本地通信子网中广播数据。这些系统由许多通过各种类型的通信网络连接的电子控制单元（ECU）组成。传统上，整车企业通过供应商来设计和构建这些ECU，然后承担整合通信和验证的责任。在此框架中，更新组件软件需要连接外部工具和更新预期的ECU。这种方法存在以下问题：
•从供应商和性能角度来看，每个ECU的软件更新都被视为一个独立事件 ，因此在设计刷新软件来说，供应商不会对自己的ECU刷新软件要花多久设置考核，更不会把它作为一个关键参数。
•通常设计过程中，只考虑单个ECU的软件更新，同时对多个ECU进行更新并没有考虑过，多个ECU同时更新所需的通信网络带宽不受任何一个供应商的控制。
•ECU之间的软件更新依赖性通常不明确。4S店经过培训之后，修理技工可以使用手动错误检测方法修补隐藏的依赖关系，在必要时安装的其他软件更新。
•有时为了保证系统的完整性，ECU的传感器或执行器需要在软件更新后进行手动操作一下
这篇文章，介绍了一下之前的事情，也提出了一种系统架构（Proposed Model of System Architecture）
系统架构可以考虑各种业务驱动因素来组织软件体系结构和软件元素。 由于车辆的生命周期通常在十年左右，因此软件更新系统本身也是可更新的。 实现这一目标的系统方法是有一套明确的可能分离的软件元素，并保证特意设计的接口不会随时间而改变。 这种方法有助于一个软件元素的变化不会影响整个系统。 软件元素可以映射到一个或多个“对象”或“服务”
