Amps output of a modern full voltage charger such as being talked of here, is purely an indication of the time it will take to full charge the battery it is connected too, eg, 110/3.6 = 30 hours, 110/5 = 22 hours
There are though losses involed so these cannot be exact times, ultimatly, a one amp output charger would be unlikely to charge a big battery as losses may overcome any gains.
Practically speaking I use a 3.6A to charge my 110Ahr battery and it does just fine, however and as Roger knows, mine is the alledged £13 'cheapo' version of the CTEK from Aldi/Lidl and personally after 4yrs use I can highly recommend it