I prefer to see a single charger due to there being less to go wrong. Just because some have good luck charging with multiple chargers how many chargers do you want to plug in each time you charge? I prefer to just to plug in one plug and go about my business as it charges up. Ready to go in the morning. If it craps out it craps out. If one of a string of chargers craps out one battery may not be charged and you may not know it and go drive and kill your battery post haste. One charger and one equal charge on the pack. How many plugs do you have anyway? I have one handy one. Not 12 or more. 
Pete
Just my opinion. I think most will agree with one charger. You could bring up some batteries to match the others but since your pack is near the end of life I guess your voltages are pretty good. My pack is near its end of life too. My charge of the 12 volt floodies only produced 80% at full charge.
Pete
Just my opinion. I think most will agree with one charger. You could bring up some batteries to match the others but since your pack is near the end of life I guess your voltages are pretty good. My pack is near its end of life too. My charge of the 12 volt floodies only produced 80% at full charge.