Hands-on hybrid electric vehicle battery reconditioning class.
Hybrid vehicle battery conditioning course
Date: March 13, 2017 (more dates to be announced)
Location: 130 N. West Street, Crown Point, IN
Day 1: 8:00 AM – 5:00 PM
Day 2: 8:00 AM – noon
Limited to 12 participants
Call 219-644-3231 for registration.
Click images to enlarge
This course teaches hybrid electric vehicle (HEV) battery safety and reconditioning. The focus is cylindrical (Honda, Ford Escape) and prismatic (Toyota, Camry, etc.) nickel metal hydride (NiMH) modules.
- Experienced instructors provide in-depth knowledge on hybrid battery cycling, reconditioning and safety issues.
- Real time demonstration of charge-discharge cycling and battery internal resistance measurements.
- Learn to identify bad modules prior to reconditioning
- Work the database for inventory maintenance and pack assembly.
- The dangers of over-charging and over-discharging.
HEV battery packs consist of 28 to 40 nickel metal hydride (NiMH) modules packed in series. A module consists of individual NiMH cells (1.2 V each) assembled in series. The left image is a 7.2 V prismatic module used in the Toyota, Camry, etc.. Detailed specifications for these modules are available. The image at the right is a pack of 28 prismatic modules with a series voltage 0f 201 V. The high cost of replacement of such packs impacts the bottom line of HEV fleet operations. However the battery pack itself should outlive the vehicle and entire pack replacement should never be required with proper pack maintenance.
|7.2 volt NiMH module Toyota Prius 28-module pack|
NiMH modules undergo shallow depth-of-discharge cycling (less than 10%) because the pack is used for power assist, not electric drive. The unused capacity material is enveloped by a resistive barrier that reduces amp hour (Ah) capacity. This reversible failure mode is the “memory effect.” The module loses memory of unused capacity and becomes out-of-balance with neighboring modules. An out-of-balance module can undergo cell voltage reversal during discharge. During a charge cycle excessive oxygen evolution can pressurize and rupture the module casing. The modules must be balanced by a series of deep charge-discharge cycles: The life of “failed” module can be recovered and extended.
Module overheating, which causes venting of the modules and loss of electrolyte water is an irreversible loss mode that leads to a permanent increase in internal resistance. Modules with high internal resistance must be removed because they substantially increase reconditioning time. It is important to distinguish between reversible and irreversible failure modes.
About the course
This one day course introduces NiMH batteries at the technician’s level and provides demonstration of split current charge-discharge cycling, internal resistance measurement, and battery pack module balancing. There are over 7 million hybrid vehicles on the road with many about to come out of warranty. Seize this opportunity!
Course Fees: $450/person (12 person maximum)
- Course work materials
- Continental breakfast, snacks & coffee breaks. Lunch on your own in the historic Crown Point district!
- Use of NuVant electronics for charge-discharge and internal resistance module evaluation
- Prismatic battery pack structure
- cell (1.2 V)
- module (7.2 V)
- pack (201 V)
- Memory effect
- Charge-discharge protocols
- Internal resistance
- Cut-off voltage
- Split current cycling
- Prismatic battery pack structure