How Does The BEQ1 Work?
The BEQ1 is not a typical
shunt battery equalizer regulator. Instead, it works with a pulse phase charger to maintain the batteries State Of Condition.
In this manner, State Of Charge equalization is automatic. Much like shoveling dirt: If your effort is spent filling
the back of your shovel, the front half automatically fills itself.
With AGM batteries, a higher terminal voltage does not necessarily indicate a higher State Of Charge
or capacity. Forcing equal voltage by shunt clamping or charge shuffling does not necessarily ensure all the batteries
in the string are actually “equal”.
The object of the BEQ1 is to equalize the batteries State Of Condition. The BEQ1 is not a "brute
force" voltage regulator; in fact it is not really intended to regulate voltage. It is designed to operate in the
recombinant pulse phase of charging. Therefore, the BEQ1 is designed for AGM batteries charged with chargers that incorporate
a Constant Current / Pulse Finish charger profile.
AGM batteries are sealed with the electrolyte absorbed in a glass mat that is squeezed very tight
between the lead plates. Therefore, they must not vent gas or air pockets will form in the glass mat causing a loss
of capacity. AGM batteries use a catalyst technology to recombine the gasses to prevent that loss. The recombination
however occurs after a full bulk charge and with a low current high voltage final charge. The recombinant process is
most effective when the voltage has reached approximately 2.6 volts per cell (15.6 Volts for 12 a volt battery), then is released.
The recombination occurs while the voltage is dropping back down to the resting voltage. This process repeats continuously
with a pulse ON for about one second and OFF for about five seconds. That is why the pulse charge is most effective.
The efficiency of the process, however, degrades when the voltage exceeds 2.7 volts per cell (16.2 volts for 12 volt
battery). The role of the BEQ1 is to reduce, but not eliminate, the pulse current in batteries over 15.6 volts.
If it eliminated the current then that battery would not receive the full recombination process. This method has proven
to be very effective in maintaining AGM battery condition and equalization. Some test results can be seen here. For more information, click here for a white paper PDF by the National Renewable Energy Laboratory regarding AGM recombination charging.
