Brentbba, no one offers a complete kit for dual batteries, there are a bunch of different ways to go about this, all have their pro’s and cons from cost, complication and electrical standpoints, if you do not have a winch and just want to power accessories with the truck off and self jump in an emergency I think the simplest is a solenoid and a second fuse box off of the second battery, the hellroaring is simple also but I don’t like the diode isolators because of the volt drop
Cruiserdrew said:
I am curious how the Blue sea relay set ups will work as referenced on that other thread.
So far mixed with the blue sea solenoid, well built unit that draws very little power to operate, 0.130A (except for inrush), I think by Monday I will have it where I want it and be happy with it.
Did not go to my original plan, when I first hooked it up I got a new noise on AM channels from the “pulsing coil optimizer” this is on top of the engine noise on AM channels I already had. The blue sea rep I talked to before buying said this was a possibility. built a filter made from a 470 μf capacitor and a choke, noise now gone except very faintly on one weak channel, I may try a 220 μf or 1000 μf cap (the other 2 sizes I have on hand) to see if it changes.
But now that leads to another problem. it will not close from the alternator good signal, I think the combined inrush of the capacitor (?A, capacitors have a very high sharp inrush that tapes off to 0A very quickly ) and the solenoid (3.8A for 130milli seconds) piss off the alternator IC regulator as its output drops to 2v when I try to close the solenoid from it. Could also be a problem in my rebuilt alternator. Works just fine in manual mode but I keep forgetting to turn it off when I shut down (the reason for auto in the first place)
I think the fix is going to be a very small mini relay rated at 10A that is closed by the signal and then powers the solenoid, this adds 0.030A power consumption to the circuit, for a total of about 0.180A constant (relay + solenoid + LED) , that would take more than 46 days to kill the 2 batteries if left on by accident, total inrush unknown. I think this will also give me a chance to power the LED’s in the switch for an “ON” and position indication instead of just switch position indication.
The relay, capacitor and choke all fit in a 35mm film canister, the filter (capacitor & choke ) alone fit in a 12ga shotgun shell.
BTW you will need a lot more than 5’ of primary wire, it took that just to go from one positive post to the other, even if you reuse the main battery wiring you still have to provide a good ground for the aux battery, I replaced the stock wires also took about 19’ total, 90 degree lugs could have shaved several feet off, used 1/0 gage cable defiantly overkill but 4ga is a little light IMO, especially if you get a hung starter.
