Some trickle chargers only trickle but some are full chargers. I have ctek charger fly leads permanently connected to my élan, my 7, my smart car, and am about to fit on my boat as well. The ctek chargers are great and will condition and charge the battery and tell you what is going on. Connect the fly direct to the battery or as near as poss. On my 7 it is on to the FIA isolator switch as this was a neater solution. I have never had to jump the elan in 15 years of ownership. If you get a good battery and look after it with a conditioner on it, it will last you a long time. I also had one on an Aston Martin which was notorious for flattening its battery and the ctek was great. The latest flyleads have traffic lights on the fly connector itself so you can see at a glance what the state of the battery is, although in the main when they are in the garage I keep them on the chargers.