Technological Advancements, Greater Energy Density with Lithium Ion

Lithium ion for forklifts & agvs

modular battery packArticle from Logistics International Pro Autumn 2017:

Although lithium ion batteries have been around for over 25 years, they are primarily used for small portable electronics and electric vehicles.  Those applications specifically require a small, lightweight energy source.  With few exceptions, lithium ion batteries were designed into these products from concept.  Recently however, lithium ion is now being looked to as a way to update existing products to take advantage of what this newest battery technology has to offer.  Traditional automobile starter batteries probably perform well enough at their current price to remain with lead acid, but other applications such as material handling (e.g. AGVs, forklifts) currently using lead acid are quickly finding compelling reasons to upgrade to lithium ion.  One enabling technology that is helping with the transition comes from Valence Technology.  Their modular approach involves making lithium ion batteries in traditional lead acid group sizes.  This allows a product which currently uses lead acid batteries to easily upgrade to lithium ion with minimal impact to the system’s architecture.

One unique design element that affords Valence to be a suitable drop in replacement is their lithium iron magnesium phosphate chemistry which operates at the same voltage range as a standard sealed lead acid battery.  Other lithium ion manufacturers such as Samsung or LG Chem cannot overlap lead acid voltages so easily.

Substituting a standard Group 27 lead acid battery with an equivalent Valence battery, reduces the weight by half while providing up to 3 times the usable energy.  And by utilizing Valence’s patented lithium iron magnesium phosphate chemistry, it will cycle up to 10 times longer, or many thousands of cycles.

Lithium ion for forklifts & agvsThis modular, common-size form factor now allows users to benefit in one of two ways:

  • Simply replacing the lead acid battery with a lithium ion battery can double or triple the run time.
  • Implementation of a smaller pack saving additional weight and the extra space can be used for other beneficial needs.

Even if lithium ion is chosen as the original energy source, modularity over a custom design has specific advantages.  Procuring standard modules allow for faster product development, shortens time to market, and includes no engineering or tooling charges.  Using modules in a system also makes serviceability much easier than a singular custom battery pack.  One benefit to creating a battery pack using lithium ion modules is if the usage demand of the application changes, the battery capacity can change as well simply by adding an additional string in parallel.  This flexibility makes the battery scalable over time, rather than developing a new battery system for each new usage case.

AGV using Lithium Ion BatteriesValence Technology has created a line of lead acid replacement modules called U-Charge®, which has been in production over 10 years.  They can be assembled in series and parallel to reach any system voltage or capacity the application requires.  These modules also include a battery management system to monitor the State of Charge, current, voltage, temperature and fault codes of each module.  The U-charge® modules are kept in stock in fulfillment centers in North America and Europe for just-in-time delivery.  Additional information about Valence lithium ion batteries can be found at lithiumwerks.com.

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