Hi,
It should not be hard to tell if a given charger can not only charge a series wired Li-ion pack but also balance it. The tell is how many wires it takes to connect the 'charger' to the cell pack. For a given number of cells N, the number of wires should be N+1.
So for one cell there would be 2 wires, for two cells three wires, and for three cells there would be four wires that connect the 'charger' to the pack. If there are any less than that then the charger does not balance the cells. This of course excludes specially designed packs that have built in charger controllers.
There is a secondary mechanism that comes into play too however. That is any built in protection of the cells used to build the pack. If they have a protection mechanism built in then they probably stop charging after a certain point, but then the other cells dont get charged enough. So maybe the pack wont blow up, but it probably wont charge correctly either.