When installing a large battery bank there are a few things we need to take in consideration both for safety and life expectancy of the batteries.
Batteries in a specific bank should be of the same make and type. Age is a factor in a battery as well.
In a series installation, when one of the batteries fails, the replacement of the whole bank becomes necessary. In a parallel installation when one of the batteries fails, that specific battery can be replaced or even removed.
Batteries should be kept in a well-ventilated and cool environment to enhance their life expectancy. For every 6 degrees Celsius above 20 degrees the life expectancy of a battery is cut in half. Make sure that the batteries are not packed together tightly either. Airflow should be encouraged between batteries to prevent overheating. Forced air is recommended in large banks.
Extending battery banks by wiring batteries from another location is highly discouraged. Different locations means different temperatures causing the batteries to act out of sync in terms of charge which can lead to excessive gassing and possible thermal runaway.
Voltage regulators for charging devices should have temperature sensors. If the batteries heat up the rate of charge should be tapered.