A commissioning charge is similar to equalize charging, but with new batteries the charging
voltage may be higher and held constant for a longer period of time to ensure the new batteries
are fully charged and to help balance the cell capacities and voltages. The following shows the
typical variation of cell voltages on float for a brand-new battery before commissioning charge:
New Battery Before Commissioning Charge
The recommended equalize charge for a Sonnenschein A600 VRLA-GEL battery is as follows:
Equalize charge is good to do on a regular basis, but for commissioning charge it is okay to use
even higher charging voltages. The factory uses 2.65V/cell for 48 hours before a factory IEEE
discharge test to make sure the cells are all fully charged and well balanced. Most equipment loads
can not handle such high voltage 2.65V/cell x 60 cells = 159Vdc so that would be done before
connecting the equipment loads. With our Sonnenschein VRLA-GEL batteries there is no worry
about applying such a high commissioning charge voltage, because our batteries are tough and
can take it with very little concern about temperature rise or water loss:
GEL Battery Overcharge at 2.65 Volts per Cell
That said, even with normal operation our Sonnenschein A600 VRLA-GEL batteries will attain
better balance over time provided that they are routinely checked and equalized according to
service recommendations:
The problem is that batteries are often ignored and not checked and tested enough during their
lifetime. Brand-new batteries may have also been sitting around for some time prior to installation
and thus the state of charge is less than ideal. If a commissioning charge is done on a brand-new
battery at least it starts out life under ideal conditions and therefore has the best chance at
providing a long service life. So, commission charge your brand-new batteries and make sure they
are checked on a regular basis, then equalize as required!