can i connect a fusebox directly to alternater lead?

[Nesta]

Hi Guys.

Electrics isnt my strong point. I have a 2013 d22 with a yd25. It has standard accessories like lights and cb.

I recently replaced my 2 cranking batteries with a single larger unit. Instead of chopping off the power lead from alternater like most old threads recommend i was wondering if i could connect accessories through a fuse box?

I was thinking of using something like http://www.gadgetcity.com.au/baintec...2215cdf4f88b77

Can someone with more knowledge than me confirm this is safe?

Thanks in advance.

[bods]

Hey mate. You can, if you would rather a 12 fuse one you can get a Narva one off eBay for just under $60. There's no reason you can't do what you want though.

The only thing to remember is that it is always going to be powered and will be drawing power from your cranking battery. Some people have connected that wire to an isolator and then to the second battery to keep them separate.

I didn't cut any cabling on mine, I just insulated the terminal end and poked it under the airbox. It has been fine for longer than I can remember now. There is a spot on the driver's side inside quarter panel to fit a redarc or similar isolator right, which I have done and ran a new cable to the second battery.

[Old.Tony]

I'm assuming the second battery is now gone, and there's just a big heavy cable sitting there waiting for you.

Whichever fuse box you want to connect to it, the answer is basically "yes". There are two approaches - as bods indicates, a direct connection leaves it connected and active at all times, because not only is it connected to your alternator, but it's connected to the other battery.

An improved method - which will safe-guard your starter battery from possibly going flat - is to put a very heavy relay in place to bring the power to the fuse box on only when the ignition is on (which means, usually, engine running). Poke through the fuse box in the engine bay for a connection that only comes on when the engine is on, and tap into that - it will draw milliamps, so won't affect whatever it is. Connect this to pin 85 of a 120A relay. Pin 86 goes to vehicle body or battery negative. Pin 30 goes to the big heavy cable and pin 87 to the fuse box. Job done. You can use an isolator instead, as bods suggests, they're more expensive but monitor the voltage not just an on-off signal.

The kicker is what you're going to do with the output from the fuse box. If you're going to run accessories from them, you run the risk of flattening the starter battery. An alternative to that is to put a deep cycle battery in where the second cranker came from, still use your fuse box, still use the heavy relay, but this time pin 87 goes to the second battery not the fuse box. The fuse box connects directly to the second battery. This gives you an isolated auxiliary battery for use when camping, without any risk at all to the starter battery.

So, yes what you're suggesting is safe, but depending on what you're trying to do with it, there might be other answers that improve the system even more.

[Nesta]

Thanks guys, thats very useful info. im planning on getting a deep cyle and isolater soon but for now i just need to hook up the accessories and tidy up some wiring.
Im not too worried about killing the battery I like to be able to run some stuff in camp without looking for the keys. its never more than a few minutes.