the processor of the computer and or other programmable data processing apparatus create means for implementing the functions acts specified in the block diagrams and or operational illustrations in some implementations the functions acts noted in the figures may occur out of the order noted in the block diagrams and or operational illustrations for example two operations shown as occurring in succession may in fact be executed substantially concurrently or the operations may sometimes be executed in the reverse order depending upon the functionality acts involved fig2 illustrates a ups system and operations thereof according to some embodiments of the present invention the system includes a plurality of upss 110 connected in parallel to a load bus 35 that serves a load 30 the upss 110 are configured to provide power to the load bus 35 from respective batteries 20 in the illustrated embodiments each ups 110 includes an inverter 112 that generates ac power on the load bus 35 from dc power supplied by the associated battery 20 each ups 110 further includes a battery load controller 114 that is configured to control power transfer from the battery 20 to the load bus 35 by the inverter 35 responsive to battery information received from the other upss 110 via a communications bus 40 it will be appreciated that in general the battery load controller 114 may be implemented using analog circuitry and or digital circuitry including such devices as microcontrollers microprocessors or special purpose devices e g asics.