[fox46]

That just sounds wrong to me. If the two chargers are not synced (and it is highly unlikely they are) and calibrated the exact same way, one may go into load test while the other is supplying current. If not closely calibrated, then one charger may go into secondary charging while the other is in primary charging.

I used four banks to charge the 100AH on-board battery on one of our carts and it seemed to work flawlessly. I don't know that it is that hard to see multiple bays working together- The charger likely senses current to identify when a battery needs to be charged and when it has had enough. If they are all running in parallel, the current the battery will accept is split between them all and assuming all the transformers are identical, they all put out the same voltage and hence see the same current. When the current drops to a level that each individual bay is happy with, it shuts down into maintain mode which applies a slightly lower voltage to the battery. If that bay is seeing a higher voltage than its maintain cycle (ie other bays are still in charge mode) it likely just sits in maintain mode and each bay will eventually shut down as each one becomes content that the battery is drawing a low enough current to indicate fully charged. I never witnessed the entire charge cycle because it charged overnight but I would expect each bay would switch to maintain mode one at a time depending on their sensitivity and calibration so you would end up with a 7.2A > 5.4A > 3.6A > 1.8A main charge cycle as the battery approached full capacity.