Whilst I've been busy connecting the dots (so to speak) between each component I'm wiring and joining things up to a fuse box the thought about how much power I'm going to need has suddenly dawned...
...I mean so far my basic brain has been thinking - oh right that's a 50W bulb so over a length of X meters I need to make sure the wire is thick enough to make sure it won't act like a fuse and ideally thick enough to make sure the voltage drop isn't so great. Essentially - so far it has been easy to say "bugger it I'll use a thick wire and hope they all go through that hole".
Now I'm figuring out the fuses I'll be needing and more importantly how these groups of fuses (and relays) are going to be connected to the charging system (the alternator) and the battery.
If I have an electrical system that needs more power than the battery and the alternator can give I'm going to be in trouble.
I've had to make a spread sheet.
Some of the values in the spreadsheet might not be 100% correct - I've had to guess - for me at the moment it is more understanding what I should be doing (even if I haven't got the right data)
I was thinking about the way in which the electrical components are connected in an automotive system and realised that the electrical loads / components are connected in parallel.
To calculate the maximum possible disaster situation of having everything switched on at the same time - I calculated the resistances of each of the loads and added then together in parallel - then this figure of total resistance got converted to a total current.
I'm not sure this is correct - can someone confirm?
A series calculation of the values in the picture above comes to 160 amps
But I think because it is all in parallel the total current draw would be 100 amps