There is a bazillion posts on this, U never have to disconnect anything to put a charger on each battery, You can charge one batt at a time if you only have one charger and allot of time, just switch it to the next one, You can put 6 -2 volt chargers on the same batt and say a 15amp on the other, Charging batts are like filling a pool, the chargers will cut off before putting more than the batt holds, so why would there ever be a reason to disconnect anything, Proper batt maintenance is important, the batts dont fail , people fail the batts by human error, once a year at least take em out clean em charge em individually and rotate them and put them back in, A clean batt holds a charge longer, dust dirt and grime leach juice, Rotating batts is important because the first batt gets all the juice when driving and the second and so on get the run off, The last batt is always a little low because the charging system only knows the first one is charged and stops when there is enough in the next batts to not let it pull enough for the charging system to recognize. so the last batts sulfate, and in time will be a problem, those with allot of these trucks, when they find the batts bad , if they take the time to test em , they will find the first batt is fine but the latter batt or batts will eventually have a bad cell, or sulfate so much it or they wont hold a charge,
