Get More From Your Solar Electric Energy
Ultra High Efficiency Flexcharge™ Controllers
Who We Are
SES Flexcharge USA is the trademarked name for all products manufactured by Seelye Equipment
Specialists (SES). SES was established in 1967. With many years of experience in the
alternative energy field we are very familuar with system sizing, design and applications that use our
Working closely with dealers and their customers during the alternative energy system designs
and troubleshooting, it became clear that the alternative energy industry was severely lacking in controllers
that offered long term dependability combined with high operating efficiencies and at a reasonable
Solid State controllers mounted on large heat sinks worked, but due to their inefficient
operating characteristics, they consum a significant amount of the charging energy generating heat at the
Before the patented Flexcharge process, relay based controllers were typically power hungry and
designed with unstable control circuits causing premature relay failure, serious over or under charging, and
over discharge situations.
Armed with this extensive real world PV system operational knowledge, the SES Flexcharge
Engineering Department created a new generation of controllers. The following criteria was used
for the design of the Flexcharge Product line.
- Ultra High Operating Efficiencies.
- Low Standby Operating Current.
- Exceptionally Accurate Voltage Regulation (Charge Controllers).
- Long Term Dependability.
- Durable (Waterproof Electronics).
- Easy to install and use.
- Intelligent Circuitry.
- Minimal User Adjustments.
- Accurate System Status Reporting.
- Install and Forget Operation.
- Competitive Pricing.
Flexcharge was issued a patent for the innovative circuitry that emerged from this effort and
which allows Flexcharge controllers to operate at these Ultra High Efficiencies.
The success of the Flexcharge product line and exceptionally low level of warranty returns is a
testament to the level which we have achieved these goals. Flexcharge controllers are operating in
harsh environments such as; Antarctica, Alaska, Africa, Saudi Arabia, FL, Canada, Mt. Everest etc.
Flexcharge offers a 5 year warranty on all model NC controllers and a full two years on most other
Our controllers are designed to be installed and forgotten. With boring monotony they will
control & and help protect your alternative energy system's battery banks, loads, and PV Array or
permanent magnet type charging source.
During phenomenal growth we have not forgotten "where the food on our dinner plate is coming
from". You, the customer, are very important to us. We have highly qualified personnel available to
answer your alternative energy system application questions from 9 am to 5 pm EST USA. For
off-hours requests, 24 hours a day, you may submit email call our line to leave a message to
have information mailed to you, or to have someone call you back. Contact
To help answer your questions as they arise we've also put a substantial effort into the
operating manuals delivered with each controller. We tried to cover the topics that a novice installer will
need to connect and troubleshoot smaller PV systems. Larger Off-Grid systems are still best left to the
Something you will notice about the Flexcharge product line is the extensive use of
non-corrosive ABS polymer enclosures instead of the sometimes more eye appealing powder coated metal
enclosures. This engineering decision was made to eliminate case corrosion and allow for the simplified
potting of the electronics, Furthermore the Flexcharge controllers operate at such high operating
efficiencies that metal cases are not required to dissipate the heat that is generated by most
controllers. This combination creates a package which is forgiving to even the worst mounting locations such
as; marine vessel engine rooms, near a lead acid battery bank, non-environmentally controlled battery shacks,
marine navigational buoys, dust and sand environments, etc.
Flexcharge™ Product Design
As an alternative energy systems distributor or dealer you want to offer your customers system
components which are the highest efficiency and quality, lowest cost and easiest to use. For this
reason SES Flexcharge USA approaches the
controller design with the end users system performance as our primary focus. As the consumer we understand
that you want a high quality, efficient controller you can install and forget about.
The first of each newly engineered Flexcharge product is put through rigorous real world, in the
field operational testing on a functioning solar or wind power generating system (you may be surprised how
many other brands are not field tested). It is then operated under, at, and over the controllers design
limits. The information gained through this testing is used for design improvements that are
incorporated before we sell the first controller. This rigorous testing ensures that the controller you
purchase will be the second generation design of the highest possible quality and reliability.
Due to the inherent high cost of generating power from an alternative energy system, each
component used in that system must operate at the highest possible efficiency. Secondly, because these
systems are often in remote locations these components must also perform at an exceptional level of
dependability. At Flexcharge we achieve this
goal through strict attention to quality at every step, from new product concept, to materials and components
used, to controller testing. Flexcharge
products are machine assembled in the USA using the highest quality
surface mount components. Each and every controller is is tested prior to shipping. Most
Flexcharge controllers are potted with a UL listed flame retarding material making them impervious to
occasional water spray and high humidity conditions.
Charging Efficiency Most other brands of controllers operate at
efficiencies near 97% or worse. That means that 3% or more of your solar panel's output capacity is used to
produce heat in the charging regulator. Flexcharge NC family of Controllers operate at efficiencies up to
99.9%. At full rated current the NC25A operates at 99.5%, using only 0.5% of your precious PV energy.
Most of our controllers use less than 5 ma of standby current. Other brands will use up to 80 ma. The
charging methods used to achieve this ultra high efficiency as well as other features, were invented and patented
Flexcharge Charge Method
Charging Algorithm Explained All Flexcharge
charge controllers use the innovative "Energy State Taper Charge" method. In alternative energy
charging systems this method has numerous advantages over the constant voltage PWM charge regulation as used
by many controller manufacturers. Click on the link for more detail.
Controller Status Displays
Flexcharge controllers were designed to minimize the display complexity and power required to
operate them, while clearly displaying the controller's basic status. More elaborate displays should be
installed as a seperate device in a easy to see location. We suggest using a switch to only have the
display turned on when you are interested in seeing it.
One question we are often asked is why we do not include volt or ampere meters, amp/hour meters,
totaling circuits, etc... in our controllers. The Reason: Usually these devices consume an undesirable amount
of precious system power and should be used only where they are really necessary, such as large scale off
grid home PV systems. For smaller dedicated PV systems like monitoring sites, navigational buoys, PV
powered street light controllers, etc. the system should be designed for unattended - non monitored
operation. The designer must ensure the project is supplied enough energy to operate, and
the PV system designer must ensure the solar powered or wind powered system makes and stores enough
energy to do the job. In smaller system installations the monitoring circuitry simply
uses up precious energy and adds cost. If you determine that you need system monitoring
equipment, install it where it will be most effective, and where it can be turned off when not in
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