P15261: Electric Superbike Off-Board Charger
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Problem Definition

Table of Contents

Project Summary

The RIT EV Team is developing an all-electric motorcycle to race in the 2015 eMotoRacing Series. The team requests a battery charger that can charge the motorcycle in a reasonable amount of time. The EV Team requests that the charger conforms to the J-1772 EV charging standard, as well as allowing the use of a traditional 120V wall input. The charger must be able to safely mount and dismount from the battery and power on/off. Additionally, features such as an LCD display, device-to-charger communication and an adjustable charge rate are desired. Due to the highly-reactive nature of the lithium-polymer batteries that will be charged by this product, safety is a primary concern, and must be considered in every design decision made. Additionally, to ensure usefulness and efficiency of the charger, it must be designed with ease-of-use in mind.

Project Goals and Key Deliverables

The ideal product will be able to safely charge the superbike’s 26 cell battery pack in less than 4 hours, the average time allotted to the EV Team between bike races. As such, the following customer requirements have been agreed upon by the customer and the development team:

Some required features include communication over CAN and the use of an LCD display. Communication over CAN¬ allows the battery charger to interface with the EVT Battery Management System and relay important information regarding charge rate. CAN allows the use of coulomb counting to measure charge rate in a more accurate way than traditional methods. The use of an LCD display allows the development team to create a user interface that will significantly improve ease of use.

Customer Requirements (Needs)

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Engineering Requirements (Metrics & Specifications)

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Constraints

Due to the reactive nature of the lithium-polymer batteries that will be charged by this product, safety is a primary concern, and must be considered in every design decision made. Emergency shutdown protocols will be implemented on the charger. The charger may also be programmed to turn off if not interfaced with by the user every 15 minutes, preventing the charger from charging the battery pack unsupervised. The development team is also working directly with EVT to be trained on EVT’s standard safety procedures. Additionally, to ensure usefulness and efficiency of the charger, it must be designed with ease-of-use in mind. Budget is also a concern to the development team. With a maximum budget of $1000, the ability to purchase high quality components is being evaluated. For example, the J-1772 charging connector typically costs around $200. Purchasing components that allow us to maintain a current/voltage regulation greater than 99% may require significant research.

Solution Parking Lot

During the Problem Definition phase, you will start coming up with possible solutions. Rather than act on those now, put them in the Solution Parking Lot, and come back to them after your team has fully defined the problem.

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