I’ve been assembly Brian O’Neill at our “Espresso, Cake and EV” mornings for the previous couple of years, and lately, our discussions have targeted on his efforts to handle diminished vary points together with his 2018 Hyundai Ioniq EV. I usually inspired him to put in writing about his expertise, and now that he has resolved the issue, right here’s his story. Please notice that this text contains many technical particulars that could be complicated for some readers.
First, a bit of background about Brian. He shared with me that he’s a retired Licensed Skilled Engineer with a Grasp of Engineering diploma in Advanced Management Methods. He has additionally been acknowledged as a Fellow of the Establishment of Engineers (Australia). His profession spanned design and troubleshooting of digital instrumentation, sensors, and energy programs in fields like area analysis and geophysics from 1954 till his retirement in 2020. It is simple to see how he managed to determine the vary concern!
On September 24, 2023, Brian made a visit from Bribie Island to Cleveland Showgrounds, beginning with a completely charged car that displayed a spread of 255km. This was a route he had taken many occasions earlier than with none worries about vary. Nevertheless, throughout this journey, he seen the projected remaining vary was reducing a lot quicker than anticipated. To preserve vitality, he slowed down. In the end, nearly 5km from dwelling, he acquired his first warning with a 13.5% State of Cost (SoC), adopted by the automobile coming into restricted energy mode after which “turtle” mode at 3% SoC. He reached his storage with the show studying zero vary regardless of having began with a completely charged battery. The vitality consumed from full cost to zero was 21.66kWh, indicating a big drop.
Because the automobile was nearing a scheduled service at 90,000km, Brian requested a battery State of Well being (SoH) examine throughout the go to to the service middle. To his shock, the battery was reported to be in “high quality” situation. Curious concerning the state of affairs, he bought an Onboard Diagnostics (OBD2) reader, which confirmed the battery’s SoH at 100%. Even when the SoC dropped to twenty%, there have been no noticeable variations in voltage between the very best and lowest particular person cells, suggesting good well being general.
Nevertheless, Brian found that the battery was not charging to the displayed 100% SoC, as indicated by voltage readings that have been decrease than these of comparable fashions. This discrepancy prompt a possible software program concern affecting the discharge voltage curve, as different automobiles of the identical mannequin confirmed constant voltage readings.
Hyundai has not disclosed the precise battery chemistry used on this mannequin, but it surely has been prompt that subsequent fashions might use NMC622 batteries. Evaluating the information indicated that Brian’s car may need been programmed primarily based on the specs for a distinct battery sort.
Brian inferred {that a} potential software program replace, probably after September 2022, impacted his battery’s efficiency. He famous a drop within the displayed vary across the time of his 75,000 km service, however initially attributed this to newly changed tires.
When Brian reached out to the Hyundai seller, they have been unable to help because the SoH readout was regular. His personal analysis confirmed that the battery contained 196 LQ1729-A2 LG Chem NMC cells, and after analyzing datasheets, he discovered that the battery’s chemistry might affect the efficiency and balancing points current.
Key observations led Brian to appreciate that:
1. Batteries degrade shortly when saved at excessive SoC, particularly in heat circumstances. Thus, sustaining a decrease SoC is advisable.
2. The SoH derived from inside resistance might not precisely mirror the battery’s capability, significantly at average temperatures.
Brian discovered that the passive battery administration system (BMS) may be insufficient for dealing with the distinctive battery configuration in his car, resulting in points with balancing the cells. His investigation into the information revealed that sure limits within the BMS hindered its capability to take care of balanced cell costs.
To sort out these points, Brian recalibrated his battery often by charging at a decrease amperage from a diminished SoC. He discovered to handle his battery utilization higher by storing it between 30% and 70% SoC except an extended journey was deliberate.
Brian’s expertise highlights the significance of understanding how battery administration programs work and the way particular situations can result in efficiency points. He famous that different Ioniq house owners might not have reported comparable points, suggesting that Brian’s circumstances may need been distinctive.
In abstract, Brian’s journey illustrates the challenges and potential options for optimizing battery efficiency in electrical automobiles. Hopefully, his insights will help others experiencing comparable vary considerations. If anybody else has confronted this concern, sharing your experiences within the feedback could be appreciated.
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