By: Matt Bridge, Director of Engineering, AMETEK Prestolite Power
Compared with today’s advanced technology, it is impressive to consider all of the developments the industrial battery charger industry has seen since 1917. When the industry began one hundred years ago, battery chargers basically consisted of a motor that generated an electrical charge. They were all mechanical and very inefficient at charging batteries. American manufacturing was at its height of importance. Companies often employed the entire population of some small towns. While times have changed and assembly lines have been updated with the latest technology, the early adapters of battery charging technology developed the core methods that are still used today.
Due to new technologies, employers today are looking for highly skilled workers educated in science and trained in technology, who can operate advanced electronic equipment, give engineers proper feedback on process changes and help and assist with process improvements.
Improved data collection, application of precise controls and high efficiency now serve as the cornerstones for battery charger technology across the industry. Fleet management software and cloud-based software is also vital to maximizing warehouse efficiency as it allows the operators to see the status of which batteries are losing charge.
Significant progress has been made in the last few decades with displays and user interface, starting from simple analog meters and mechanical timers to the now endless menus for precise control and display we have today. Strong innovation in data storage has been made to make charger and battery history available to browse as needed in order to efficiently manage a fleet. The technology went from “not available” to providing endless amounts of data for evaluation.
Motive battery charger purpose
The purpose of a motive battery charger is to charge the battery to keep the material handling equipment moving, maintain the battery to maximize the uptime, maintain the battery to maximize the lifetime and interact with battery devices to store battery information to help manage a fleet of batteries.
Charging termination types and methods
The three dominant charging termination types include: voltage time, which almost always results in overcharge; DV/DT, that works well until batteries are left at a low state of charge; and target voltage, which must be adjusted with battery temperature and aging. All termination methods are estimates, therefore, strong preventative maintenance is required with current technologies to maximize uptime and battery lifetime.
What can be measured during the charge curve?
Common measures include cell balance, volts per cell, electrolyte temperature and electrolyte level. A proposed new measure takes into account the electrolyte’s specific gravity, the ratio of the weight of the battery electrolyte as compared to an equal volume of water. It is the most accurate measure of state of charge.
True management of a battery
Using the new specific gravity value and all other common measurements, the envisioned battery management system could actively manage the battery over its entire lifetime. Steps taken in managing a battery include, charging using a specific gravity and managing equalize schedules, temperatures and the amount of recharge in opportunity charge applications.
Effects of not charging properly
Overcharge both reduces battery life and comes with higher energy costs. Having an accurate measurement of undercharge minimizes sulfation, the damage caused when large crystalline deposits build up inside the battery, reducing battery life, capacity and its ability to accept a charge. An accurate measurement of battery charge will prevent frequent motive battery charging, minimize costly battery replacements and take manufacturing and warehousing operations to a new level of efficiency.
What technology innovation is needed?
The goal for advancing battery charging and management innovation is to develop the technology to the point where it is intelligent enough to require little to no supervision.
We need to manage batteries to:
1. Make them last as long as possible.
2. Ensure the most uptime possible.
3. Use the least amount of power possible.
- The battery management system should not require a user to adjust settings throughout the batteries life.
- The battery management system should recover a fleet of existing batteries from a mismanaged condition.
- The battery management system should constantly track battery conditions to make sure the charger terminates on target.
New battery management innovations could increase both uptime and battery life dramatically. Battery management systems with upgraded instrumentation could provide true state of charge for every charge cycle. Ultimately, the goal is less down time, less required maintenance, longer usage cycle and lower energy costs, which results in lower total cost of ownership.
AMETEK Prestolite Power offers the industry’s broadest range of industrial motive power chargers and is the only industrial battery charger provider able to custom tailor a system that combines the full range of conventional, opportunity and rapid charging solutions. Prestolite Power is a unit of AMETEK, Inc., a global manufacturer of electronic instruments and electromechanical devices. www.prestolitepower.com