Fast, Rapid or Quick

Fast Charge 101
December 15, 2017
Auto Supplier Produces Fast Charge Milestone
December 22, 2017

In the world of industrial batteries, the terms “fast charger,” “rapid charger” and “quick charger” can be used loosely.

​A true fast charger is part of an engineered system matching the right-size battery to the right-size charger. This allows a forklift to run through multiple shifts using only one battery.

​If you’re thinking about switching your forklift fleet from battery changing or liquid propane to fast charging, this checklist will help you pick a fast charger capable of powering your high demand, multi-shift operation.


First, make sure your fast chargers include real-time temperature control and correction. fast charging is more than just charging fast – it’s about precise control of the charge curve. Minimizing heat, off-gassing and battery wear require precise control. If your charger only shuts off when the battery gets too hot, it may not be engineered for the demands of fast charging.


Be sure your fast chargers monitor the battery’s voltage and current to prevent overheating and maximize throughput. Throughput is the amount of energy that a system needs to power each shift. Think of the battery as a gas tank, with electricity as the fuel measured in Ampere Hours (AH) instead of gallons. By combing the ability to quickly “fill” a battery with constant monitoring, a true fast charger allows an operation to maintain maximum throughput.


Be sure the up-front application modeling includes worst-case scenarios, peak season operating needs and growth projections. Simulation software can model and compare aspects of chargers, including throughput limits and charge rates. By properly sizing the system, power can be delivered consistently and efficiently, even during peak demand time.


Look for an intelligent management system that automatically recognizes the need to finish and equalize (EQ). Fast chargers should make it easy for operators to perform this weekly activity.


For industrial forklift batteries, there are three levels of charging:

  • Conventional: used in both battery changing and for single-shift operations, conventional charging returns 16-18 amps per 100-ampere hours, for a charge rate starting at 16-18%. Conventional charging typically requires 8 hours of charge time followed by 8 hours of cooling prior to use.

  • Opportunity: used by single-shift and light-demand 2 shift operations, opportunity charging returns 25 amps per 100-ampere hours, for a charge rate starting at 25%. Opportunity charging avoids the need to change batteries but may not deliver enough energy for high-demand operations. Some opportunity chargers are called “rapid” or “quick.”

  • Fast: used by medium- to high-demand 2 and 3 shift operations, fast charging returns 40-50 amps per 100-ampere hours, for a charge rate starting at 40-50%. This allows a forklift’s battery to be charged in short bursts during breaks, providing enough energy for all-day, heavy-duty forklift usage. This is a true fast charger.


Finally, the charger should be truly flexible, accommodating a wide range of battery voltage and AH configurations. This offers the ultimate in cross-compatibility among forklifts in the existing fleet and helps to inform future decisions as forklifts are being replaced.