Page 8 - PS Battery Guide May 18

Battery guide For PowerSpout

Chart of cycle life versus DOD for a Trojan T-125 battery
For example it can survive 1200 cycles at 50% DOD

Multiple strings
If you add parallel strings of batteries to a bank, this increases the Ah capacity.
For example 3 x 400Ah strings in parallel make up a 1200Ah battery bank.

Energy capacity kWh
Energy capacity may not be listed in the specifications but it is the bottom line
for most renewable energy applications. You can calculate it from the above
parameters as follows.

Energy capacity = V x Ah x DOD% / 100,000

For example a 6V, 400Ah battery that you will discharge to 50% of its nominal
capacity has the following energy capacity = 6V x 400Ah x 50 /100,000 = 1.2kWh

If you have eight such 400Ah 6V batteries then they can offer approximately
10kWh of energy storage on a regular basis (50% DOD). This capacity is valid
whether connected in a series string as shown above or in 2 parallel strings of 4
(24V 800Ah) or 4 parallel strings of 2 (1600Ah at 12V).

© 2018 EcoInnovation Ltd (NZ) Page 8
Last reviewed 19/6/18