26 | SAMLEX AMERICA INC.
7.15.3 Series – Parallel Connection
6V
12V String 1
12V String 2
Battery 1
Battery 3
Battery 2
Battery 4
6V
6V
6V
12V Inverter
or 12V Charger
Cable “A”
Cable “B”
Fig. 7.4: Series-Parallel Connection
Figure 7.4 shows a series – parallel connection consisting of four 6V, 200 AH
batteries to form a 12V, 400 Ah battery bank. Two 6V, 200 Ah batteries, Batteries 1 and 2
are connected in series to form a 12V, 200 Ah battery (String 1). Similarly, two 6V, 200 Ah
batteries, Batteries 3 and 4 are connected in series to form a 12V, 200 Ah battery
(String 2). These two 12V, 200 Ah Strings 1 and 2 are connected in parallel to form a
12V, 400 Ah bank.
!
CAUTION!
When 2 or more batteries / battery strings are connected in parallel and are
then connected to an inverter or charger (See Figs 7.3 and 7.4), attention
should be paid to the manner in which the charger / inverter is connected to
the battery bank. Please ensure that if the Positive output cable of the battery
charger / inverter (Cable “A”) is connected to the Positive battery post of the
first battery (Battery 1 in Fig 7.3) or to the Positive battery post of the first bat-
tery string (Battery 1 of String 1 in Fig. 7.4), then the Negative output cable of
the battery charger / inverter (Cable “B”) should be connected to the Negative
battery post of the last battery (Battery 4 as in Fig. 7.3) or to the Negative Post
of the last battery string (Battery 4 of Battery String 2 as in
Fig. 7.4). This connection ensures the following:
- The resistances of the interconnecting cables will be balanced.
- All the individual batteries / battery strings will see the same series resistance.
- All the individual batteries will charge / discharge at the same charging
current and thus, will be charged to the same state at the same time.
- None of the batteries will see an overcharge condition.
SECTION 7 |
General Information on Lead Acid
Batteries
