Dual batt and alt options?

Ask technical questions about your Ford Bronco II here. Technical write-ups on your axle swaps, engine swaps, chop tops, etc. are encouraged.
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Lance Skene
Posts: 144
Joined: Fri Dec 27, 2013 8:06 am
Location: Calgary Alberta

Dual batt and alt options?

Post by Lance Skene »

After doing the duraspark swap I have alot of room under the hood so Im thinking about the possabilities of running dual batteries and a higher output alternator.... ne1 have examples, ideas and/or suggestions?
'80 Bronco 351M
'85 BII 2.8/Duraspark
'89 F150 302 Supercab
dgl6y6
Posts: 84
Joined: Wed Jul 22, 2009 8:56 am
Location: St. Louis

Re: Dual batt and alt options?

Post by dgl6y6 »

130 amp alternator from 2000 ish taurus is almost direct swap.
You will need:
Alt bracket from 2.8 motor (or extend yours somehow).
6 gauge wire, ring terminals
battery isolator
130 Amp Megafuse
2nd battery Duh

Its pretty straigtforward. The regulator plug is the same as factory. The white wire connects to the remaining pin with a female blade terminal. Then its
Alt
Megafuse
Isolator
Battery Battery

I also recommend connecting the old alt wire (the one going to the fuse block) to the alt post on the isolator. this will take some of the load off of the wiring coming from the battery.

If you are lazy you can just use an alternator for 87-90 escort. That is actually a direct swap but you only get 15 extra amps. I just want to say that if you go the lazy route, keep in mind that wire coming from the alt is only 10 gauge which is rated for 30 amps. And the charging circuit for the main battery is 12 or 14 gauge. If you try to charge 2 batteries from there with accessories hooked to the batteries you are going to be a sad panda when Your truck burns down.

I say, If ur gonna upgrade, do it right.
Lance Skene
Posts: 144
Joined: Fri Dec 27, 2013 8:06 am
Location: Calgary Alberta

Re: Dual batt and alt options?

Post by Lance Skene »

Thx, Im just debating and considering the possabilities at this point but its something I can do easily and at very little cost. I work in metal fab so brackets or a batt tray is not a concern at all. Over the past few years much of the original wiring has been already replaced and/or upgraded and I tend to go overkill on most projects... sometimes overkill and lazy go hand in hand..lol.

Ive added several lights to the truck and often use them since I drive home from work about 30 minutes at 2am on dark highways, lots of deer around here, I often pull a small utility trailer that has its own winch, sometimes carry along a 12v cooler, I plan on an onboard compressor, a winch and/or maybe a plow because we get alot of snow sometimes. I dont play in the mud or off road alot but I do hunt so Im off the beaten path with this truck at times, now with all computer and smog control crap gone theres plenty of room under the hood so a dual batt system seems a fairly logical upgrade.
'80 Bronco 351M
'85 BII 2.8/Duraspark
'89 F150 302 Supercab
dgl6y6
Posts: 84
Joined: Wed Jul 22, 2009 8:56 am
Location: St. Louis

Re: Dual batt and alt options?

Post by dgl6y6 »

I hope you don't plan on running all that stuff at the same time lol. I don't know how much you like your AC but there's a pretty neat thread on converting your AC compressor into an air compressor for onboard air. You can even wire up a pressure switch on the tank to cycle the AC clutch on and off automatically.
Lance Skene
Posts: 144
Joined: Fri Dec 27, 2013 8:06 am
Location: Calgary Alberta

Re: Dual batt and alt options?

Post by Lance Skene »

I dont have AC but I have a small 12v RV compressor w/1.5 gal tank that I always drag around on hunting trips, normally it just gets plugged into a lighter type socket but I want to install it under the hood and hardwire it in, its only slightly larger than the battery so theres enough room for it and a second battery now that all the smog stuff is gone, and the air hose is stored in the old jack compartment since I carry a jack-all up in the roof rack.
'80 Bronco 351M
'85 BII 2.8/Duraspark
'89 F150 302 Supercab
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