Iota Balanced Battery Bank Charging Instructions

Optimal Charging for Multiple Batteries in a Bank
IOTA ENGINEERING
2
Effect of Resistance in an Unbalanced System
Realizing the effects of resistance on batteries connected in parallel is best demonstrated through a common method of
wiring them (see Figure 1). In typical applications, the batteries are connected side-by-side (negative to negative, and
positive to positive), starting with the rst battery connected to the second, and so on until connecting to your
battery charger.
Theoretically, each battery would be receiving the same amount of current when charging, however, small yet measurable
amounts of resistance between each battery connection makes this not the case. In reality, the battery connected directly
to your charger (in this example, battery D) will draw more amperage than the battery furthest down the bank, as the
current is reduced through each interconnecting lead.
This difference in current between the closest and furthest batteries from your charger can be very signicant (often up to
twice the amount of current drawn by the closest battery, see Figure 2), and this effect only increases as additional batter-
ies are added to the system.
To counter this, your batteries should be wired with “Balanced Charging” in mind, which basically means that the total
number of leads that separate your battery from the charger is equal for each battery.
Figure 1 - Unbalanced Charging
A common, yet inefcient way of
charging batteries in parallel.
Figure 2 - Unbalanced Charging
Each battery draws less amperage
as power passes through an increasing
number of interconnecting leads.
Draws 17.95 Amps
Draws 13.1 Amps
Draws 10.2 Amps
Draws 8.9 Amps
A
B
C
D
A
B
C
D
Approximate Amperage Drawn Per Battery
if the Charger is Providing 50 Amps.