Vintage Boat Electrics

[Murphyv310]

I remember in days gone by you often had to use a parking light on a car, these would be either 5 or 10 watts. Even with inefficient dynamo charging the cars would still start.  Today some cars draw up to 500ma after stopping for up to an hour before going to sleep then a drain of between 30 & 100ma dependent on vehicle..
Modern car batteries are allegedly far better on low current drain than older types due to the demands of modern electronics