More than 4 12v batteries in a Bank?

What would keep you from stacking more than 4 batteries? 

Never heard that not to say its not true. I have 8 100 amp hour 12v batteries in my bank. Have the positive for inverter and charger on opposite ends than their negs. Thought about it pulling off one battery more that the rest and killing that battery so did it that way so it has to pull through the bank and charge through the bank also. You have any links to that data?

A few months now I have been at over 4 . Been adding 1 or 2 a month. Gel cells are expensive and thats what im using due to having my setup in the house. Up to 8 for about a month now. I found this link in another post on here and they are saying you are good up to eight doing it like I done mine. Did find out off that I have my charger hooked up to wrong terminals though I thought you shouldnt hook it up to same ones as inverter but guess I was wrong.

http://www.smartgauge.co.uk/batt_con.html

  Im using 16 105 amp gels 4 rows in series and 4 rows parallel  for 48volt. works great also have outback controller going in one row and out the last row to the inverters.

Think in terms of how a battery is built and how it works.
The most basic battery is a nominal 2 volt cell.
A 12 volt nominal battery is built as 6 - 2 volt cells in series. One cell can go bad and this disrupts the line of chemical exchange in the rest of that battery and any other battery that might be in parallel with it. If several 12 volt nominal batteries are wired in parallel this increases the chance of a disruption caused by just one faulty 2 volt cell within one 12 volt battery. One bad apple does spoil the whole bunch in this case. Its a major chore but, one could periodically remove the wiring harness from a parallel "string" of 12 volt nominal batteries and check each one individually to insure that each battery is up to "par" or, build the same amp hour capacity battery with 6 large 2 volt nominal batteries and if there is a faulty cell you'll know it right away. Its my opinion there is no right way or wrong way, one just makes sacrifices of one aspect in the hope of gaining in another aspect. Of course if a sacrifice is made in order to, lets say, save money in the here and now, then one has to know what the consequences are going to be and follow through to the end. But you already know this, thats why you are here trying to find out those consequences. Seeking the opinions of others that have been there and done that.

The amp hour capacity would come in to play but I would say, if its possible, use 6 - 2 volts cells. Fewer cells to fill, fewer connections to maintain, if one goes bad, you know it right away. But then I don't have a lot of free time one my hands. If I did, I might say just the opposite and possibly save some money in the here and now with 12 volt batteries even though it might cost me more over the long haul if one cell in one battery goes dead and I don't catch it in time to save the others from being dragged down.