What is it?
High frequency battery chargers are a more efficient way of charging large batteries, such as those used in electric forklifts. Most existing chargers currently used are either of two types: ferroresonant or silicon controlled rectifier (SCR). These are generally less expensive, but also less efficient. There are also less-common hybrid chargers (also known as controlled ferroresonant) which are only slightly more efficient than ferroresonant.
How does it work?
Battery chargers convert standard AC power to DC power to store in a battery. High frequency chargers use more advanced circuitry to convert the power at higher frequencies, which reduces conversion losses and improves charging efficiencies.
What are the most appropriate applications?
The best applications are warehouses or industrial facilities that have significant forklift usage and operate two or three shifts per day. This usually corresponds to at least two battery charges per day for each forklift.
What are the savings?
Switching from standard SCR or ferroresonant chargers to high frequency chargers leads to standard savings of about 7%. This is based on average equipment efficiencies, but it is not uncommon to see savings upwards of 15% depending on the specific existing and new equipment efficiencies. With an average of about two charges per day seven days per week, the expected savings would be about 2,000 kWh to 5,000 kWh annually, per charger.
What are the non-energy benefits?
In most cases, high frequency battery chargers will have a higher power factor than the existing chargers, especially when compared to SCR. If the customer has a large number of chargers and power factor issues, this could help facility power factor and reduce power factor charges.
What is the cost?
As of this writing, costs for these chargers range from $1500-$2500 per unit.
What is the status/availability of the technology?
This technology is readily available through multiple vendors.
What kinds of incentives/programs are available?
Right now, this technology would typically be evaluated under Custom Rebate programs, although some programs offer prescriptive options. Depending on program requirements, it may take a project scope consisting of multiple charger replacements to make a viable project.