Agree with most of the points above:
1 Make sure your charger is a "top-up" model which shuts off when the battery is fully charged , a trickle charger will keep on charging which can lead to problems.
2 It is better not to use the cigarette lighter , a simple flying lead from the battery to a location behind the seats is preferable. I have always used this on my +8 without any problems. The cigarette lighter socket in my tin top is so poor it will hardly charge my phone which is milliamps , a battery charge is likely to be 1 to 2 amps.
