The Flexcharge™ Charging
The Flexcharge Energy State Taper Charge Process monitors the
battery for the full charged resting voltage of the batteries cells.
There are tremendous advantages to this charge method.
- Zero overcharging
- Less need for temperature
- Exceptionally low gassing (Up to 90%
- Non-Destructive Micro-Equalization at each
- The battery's chemical processes actually
control the charging
- No RFI or EMI emissions to interfere with
The Flexcharge method greatly reduces the need for
temperature compensation. This occurs because the plate voltage is not constantly held at the critical plate
saturation point. Tapering is controlled by the battery's level of charge rather than with timers, or fixed
voltages as in PWM and other constant voltage charge methods. The battery takes exactly what it needs rather
than being forced to take a set voltage. With the Flexcharge method you can charge your
battery bank indefinitely and overcharging will not occur. The batteries will last longer,
require less watering maintenance, and hold a better charge.
As charging begins the controller allows full charging
current to pass directly to the battery. When the battery voltage rises slightly above the plate saturation
point, the controller opens the charging circuit. Much like a sponge will continue to absorb water towards
its center after it has taken it all into its surface, the chemical charging process continues after the
charging current has been removed. As the charge is absorbed the battery's voltage will fall.
When the battery voltage has floated down to approximately 13.5V to 13.8V on a 12 V system, it is
ready to accept another charge pulse. This charge regulation method is actually controlled by the battery's
ability to accept and absorb energy. When the battery needs more energy indicated by plate voltage, the
controller applies it. Mid way in the charging cycle the controller will cycle ON and then OFF sending full
charge current pulses into the plates. A process which charges with very low gassing, and equalizes the
plates with each full charge. As the battery reaches a higher level of charge the amount of time the
controller spends in charge is reduced, and the time in rest is increased. At full charge the controller will
apply short duration pulses to maintain the battery at an average voltage of about 13.5 volts. This keeps
gassing to a minimum while effectively trickle charging, and equalizing at the same time.
There has been a lot of discussion over which charge
process is better, PWM, or this method. To add fuel to the fire, each company making "ON-OFF"
controllers has chosen different voltages to set the disconnect and reconnect points. We have seen
controllers using a version of this method where the reconnect voltage on a 12V system was set at 12.6V @
70°F. On this system the batteries would never see more than 80% charge, and likely much less.
The PWM type controllers will obviously regulate the charging your batteries, and with proper temperature
compensation, heat sinks, and the correct Bulk-Regulate-Float (3 stage) algorithm will do a pretty good job
of it, but why settle when you can get so much more in a charge regulator. Instead of three stages with
PWM you get an infinitely variable charge process which will supply the battery with exactly what it needs
and only when it needs it. You get less plate saturation gassing, non destructive equalization and Zero
EMI as well.
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