Each section is 2.2A for 6s, so it is 200W total, or 50W per 6s pack.
Actually, this isn't such a bad way to go, if you already have a 200W+ 12V supply. You could always cut down the total charge time by using something like the Meanwell supplies in parallel, to bulk charge the pack, and use this to "top-off" and balance the cells. Actually, it's too bad these won't accept a higher input voltage, like the
iCharger 208B, which accepts an input voltage of up to 30V, I think. That way the Meanwell can be used, either by itself as a bulk charger, or with the charger/balancer. These things are $200, though, and that is just for one 6s section, so you'd need at least two to do a 12s pack. Some of the 6s balance chargers can take 18V, so you could probably use these with a 24V/15A S-350-24 Meanwell supply, which can be dialed down to close to 18V, I think. You would start out with the Meanwell set to about 24-25V and then when it starts to go into the CV mode, you could dial the voltage down to 18V, and insert the 6s balance charger in between the supply and the pack. This wouldn't work for this Quatro 4-channel version though, as it has an input voltage limit of 15V. The S-350-24 doesn't go that low. The other problem with this approach is that during the "bulk charge" mode, where just the Meanwell is being used, there's no HVC protection at the cell level, to catch a cell about to go into thermal runaway. That alone would be a showstopper for me.
The other issue is that these RC balance chargers are all designed to be used with packs that don't usually exceed 5Ah, so the balance current is limited. At least most of these HC units will do 300mA, but balancing even a 10Ah pack can take quite awhile, unless you balance the pack with each charge, to not let the cells get too far apart. Even then, it takes time.
I looked at all these options before deciding to ge ahead with my own 12s balancer, because I just couldn't find an off-the-shelf solution that could safely charge and balance a 12s pack quickly, that didn't cost a fortune. I still continue to look for more options, though.

If I could find a cheap ($35?) 6s-50W balancer that could accept a 24V power input, I'd do a simple HVC circuit that would cutoff the main supply if a cell goes too high, and parallel the Meanwell with the balancer. By the time the MW got the pack up to the CV point, the current is going to start dropping anyway, so the cheap balance charger wouldn't have to do the heavy lifting.
-- Gary