I would connect to the battery end of the cables.. Here is the reason:
When the inverter first kicks in it often does a test, during this test it may draw watts RATED/10 amps from the battery, then it stops and settles down to Watts-load/10 or there abouts.. For my inverter that initial "kick" is 200 amps.
Not think of a water pipe.. You have wate flowing at say 20 GPM, and suddenly you slam the valve shut.. You hear the pipes ratteling throught the house. right. Well that pipe rattle in electronics is Inductive spike. the instant voltage at the inverter terminals can go from 12.6 of the batteries to 126 or more when it throttles back.. Depending on the size of the inverter 12 volt cables and the length of the run. The inverter can deal with this, the charge controler.. Will likely be damaged over time.
Now at the battery end there is also a slight kick, that 12.6 may climb as high as 13 or 14, well within the charge controller's design parameters.