Electrical Compatibility
1.1 Voltage
UPS systems have a rated DC voltage but can accommodate a certain range of DC (battery) input voltages. Therefore, they can generally accept battery packs with different numbers of series-connected cells. However, proper configuration should be completed before deployment to ensure the UPS recognizes the actual battery cells used, thereby determining their charge/discharge termination voltages and establishing detection benchmarks.
1.2 Current
During UPS operation, several distinct scenarios involve varying current magnitudes and durations.
At power-up, the internal battery input terminals contain filter capacitors. Consequently, the batteries charge these capacitors during the initial power-up moment. Due to line impedance, the peak battery current can reach 200A for a duration of <100μs. The battery pack should either have a pre-charge function or be capable of filtering this spike current without triggering short-circuit protection or other protective mechanisms, and certainly without causing damage to the battery pack.
During steady-state discharge, the UPS discharges energy ultimately in the form of sinusoidal AC power. Consequently, the current exhibits ripple. Additionally, energy conversion within the UPS incurs certain losses. Therefore, the relationship between the actual discharge current (A) , power , and the battery's minimum voltage is as follows:

The long-term discharge current rating of the battery pack should exceed the actual steady-state discharge current.
During UPS operation, mains power interruptions or sudden startup of downstream output loads may occur, causing transient changes in battery current.
1.3 Capacity
Battery capacity is clearly related to load size and expected backup duration. Considering energy conversion losses, batteries should not be fully discharged. Recommended battery capacity configuration is:

Where: is the actual capacity in Wh,
is the actual load power in watts (W),
is the expected backup time in hours (h).

Battery capacity configuration must also account for discharge rate considerations:

1. 4 Battery Discharge Rate
   In certain applications where backup time is short, smaller battery packs can theoretically be configured. However, it is crucial to ensure that during steady-state discharge, the actual discharge rate does not exceed the maximum allowable discharge rate of the battery pack. The actual discharge rate is the ratio of steady-state discharge current to battery capacity (Ah), calculated as:

Where: represents the battery's actual capacity in Wh,
is the actual discharge current in amperes (A),
is the rated voltage of the battery pack, in volts (V),

1.5 Structure and Strength
Battery packs are typically assembled from individual cells and can be configured into specific shapes and dimensions. The structural design should accommodate placement within the target space while ensuring smooth wiring connections without repeated folding. Appropriate mounting brackets and protective casing materials must be used to secure the assembled cells and withstand mechanical vibrations and physical impacts without disassembly, detachment, abrasion, or short circuits.