From The Hybrid Shop: How to Test & Diagnose Hybrid Vehicles
As often as we at The Hybrid Shop sing the praises of battery pack conditioning, and as firmly as we believe in its potential to jump start any shop’s foray into the world of hybrid vehicle maintenance, our training programs touch on much more than conditioning alone. Hybrid drive systems–much like traditional internal combustion systems–consist of interrelated and interdependent components, and thorough HEV maintenance begins with an understanding of these components not only as they function together, but also at an individual level.
While many of our customers only make their way through our doors once they’ve begun to experience acute problems with their hybrid vehicles, the revenue-generating potential of preventative maintenance is not to be underestimated. Whether concerned with the future health of their vehicles or curious about the condition of a used vehicle up for sale, customers understand the value of identifying potential problems before they arise. In this spirit, we’ve developed a cadre of minimally invasive tests and analyses which can gauge the health of the battery pack, electric machine, and power inverter assembly with a high degree of accuracy.
The Hybrid Battery Pack and Stress Testing
Stress tests allow a technician to appraise a particular battery pack’s likelihood of responding positively to a conditioning cycle without having to remove the battery from the vehicle. A ten to fifteen minute drive cycle typically provides enough data to determine to what degree conditioning may be able to improve the vehicle’s performance and fuel economy. Taking proactive measures to improve performance before a battery pack reaches end stage failure can extend its life expectancy and reduce the need for replacement parts down the road, while also providing customers with tangible proof of conditioning’s efficacy.
Predictive Maintenance for Electric Machines
The electric machine is not only the second-most likely component in a hybrid vehicle to experience failure, but also happens to be particularly tricky to analyze–tricky, but not impossible.
Predictive maintenance allows us to compare an electric machine’s current condition to what it would’ve been when brand new. Using industry standards for electric machine wear, it is possible to deduce a given machine’s ideal state of health, which can then be contrasted with it’s actual state of health, providing the customer with a clear picture of where their vehicle stands in comparison to others of a similar age.
The Often-Overlooked Power Inverter Assembly
Despite being a discrete component requiring individual evaluation, the power inverter assembly is often compounded with the electric machine when being evaluated by shops lacking the tools and processes to adequately separate the two. Scores of electric machine repair bills could likely be cut in half given the ability to analyze the power inverter assembly on its own; too often, perfectly functional inverters are replaced along with faulty electric machines due to a lack of precise diagnostics.
Analyzing a power inverter assembly’s output–how and when it is switching–can afford a fairly detailed understanding of its overall condition. While there is no way to physically test individual components within the power inverter assembly, by using current clamps to evaluate how it takes the charge back from an electric machine serving as a generator we are able to search for signs of early stage failure.
Breaking down the larger hybrid drive system in this manner allows intermittent problems to be targeted much more precisely than would be possible with traditional, non-HEV-specific diagnostics.
This is more valuable information from TheHybridShop.com. HECN is happy to welcome the TheHybridShop.com, a new green automotive startup, as our first Service Advisor. The mission of The Hybrid Shop is to “provide the highest quality maintenance, service and repair experience for hybrid electric vehicle owners.” Read more about them and servicing hybrid electric cars here. You can also find them on Facebook, Twitter, LinkedIN, Google Plus, and YouTube.Click here for reuse options!
Copyright 2014 Hybrid and Electric Car News