10.9 Torque
The maximum torque load of intercell connector bolts
is provided on the front battery label based on the size
of the battery. A loose connector can cause problems
in charger adjustment, erratic battery performance, and
possible damage to the battery and/or personal injury.
Finally, install the connector covers (optional).
10.10 Connecting the Batteries
Please be aware of the risk of short circuits when
connecting batteries in series strings. A short-circuit can
result in the arcing of very high currents. Circuit breakers
or other means of disconnection should be in an open or
off position.
A torque wrench, set to proper torque values according
to the battery label, must be used for making the
terminal connections. When heavy cables are used they
need to be supported with cable ties in order to limit
stress on the battery terminals.
Check that all contact surfaces are clean, and then install
the bloc or cell connectors and the terminal screws.
Tighten the screws securely. Follow the polarity to avoid
short circuiting of cell groups. Finally connect the battery
terminals. The insulation covers should be put back after
all connections have been completed.
See the following figures:
Insulation Cover
10.11 Front Terminal Adapter
NSB UPS batteries may be ordered with optional front
terminal adapters if front terminal access is required in
the installation.
19” Battery w/ Front Terminal Adapter
23” Battery w/ Front Terminal Adapter
10.12 Battery Connection to Load/Charger
Select the proper size and type cable and busbar per
the NEC or other applicable code which can handle the
charge and discharge current related to the battery.
The cable size selected should also consider the cable
resistance per foot and the voltage drop allowed
between the battery output terminals and the load.
A cable voltage drop of no more than 0.5V is recommended.
10.13 Parallel Battery Strings
The following guidelines should be followed when
operating parallel strings of batteries:
• Batteries should all be of the same model number
• Each string should be connected to an individual
disconnect or circuit breaker
• Cabling to each string should be of the same size
and approximate length resulting in the same
resistance per string.
Form: SES-541-01711
Issued: 12-08-16
ECO-101191