Is anyone electrically self sufficient - What's your set-up?

[fishermantwo]

So what happens when it is fully charged?

Presumably the same as a car battery charger, just cycles and floats the battery.

 

[TQA]

Presumably the same as a car battery charger, just cycles and floats the battery.

Therefor once the battery is fully charged, which is desireable, the additional drain of having the battery plugged in should be negligible ?

I am interested in this because I have a situation where if I start with a fully charged battery my 12 volt supply device will run the lappie all day and we finish up with a fully charged battery BUT if it is less than fully charged the 12 volt supply device can't cope and the battery goes to 0% in about 2 hours which is little more than it's non charging duration.

 

[Conachair]

Therefor once the battery is fully charged, which is desireable, the additional drain of having the battery plugged in should be negligible ?

I am interested in this because I have a situation where if I start with a fully charged battery my 12 volt supply device will run the lappie all day and we finish up with a fully charged battery BUT if it is less than fully charged the 12 volt supply device can't cope and the battery goes to 0% in about 2 hours which is little more than it's non charging duration.

When I eventually fing my 12v laptop charger I'll stick a meter on it and find out

But there may be downsides to taking the battery out. i think there's a good chance that when you start the engine you'll loose voltage to the lappy and need to reboot. Or if you knock the lead same thing.

Also, dc-dc is better than an invertor according to here - http://www.pbase.com/mainecruising/inverter_inefficiency

 

[fishermantwo]

When I eventually fing my 12v laptop charger I'll stick a meter on it and find out

But there may be downsides to taking the battery out. i think there's a good chance that when you start the engine you'll loose voltage to the lappy and need to reboot. Or if you knock the lead same thing.

Also, dc-dc is better than an invertor according to here - http://www.pbase.com/mainecruising/inverter_inefficiency

Yes starting the engine will turn off the laptop. DC-dc is far better than an inverter. Best is 12 volt direct if you can get away with it. Even the dc - dc convertor gets warm so obviously drawing extra current.
The ultimate is a 12 volt computer built for exactly the environment we are talking about. Searching the various electronic navigation forums will provide the recipe for putting together such a unit.

 

[Conachair]

Pricey but some lovely stuff here
http://sttechmarine.co.uk