Dual battery question on gas 7.3

Akwagon

Tremor Fanatic
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Anchorage. AK
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2021 Velocity Blue Tremor 7.3l
Trying to finalize my tremor order. Decided no which.

debating dual batteries. Concerned with the simple extra complexity of the system. I’m not to familiar with the system and have a few questions.
I know it’s a parallel system. Is it just some wires, or a circuit board controlling

it comes with dual alternators.... if one goes out is the other still able to function normally?

same thing with the batteries (say battery goes bad in a few years). If one dies it doesn’t drain the other?

wondering if it’s worth the cost vs complexity. Vs right now not seeing a huge need for it.... but never know down the road and I’ve seen on here it’s much cheaper to order then add down the road......
 
Trying to finalize my tremor order. Decided no which.

debating dual batteries. Concerned with the simple extra complexity of the system. I’m not to familiar with the system and have a few questions.
I know it’s a parallel system. Is it just some wires, or a circuit board controlling

it comes with dual alternators.... if one goes out is the other still able to function normally?

same thing with the batteries (say battery goes bad in a few years). If one dies it doesn’t drain the other?

wondering if it’s worth the cost vs complexity. Vs right now not seeing a huge need for it.... but never know down the road and I’ve seen on here it’s much cheaper to order then add down the road......
I personally like the integrated winch.

Batteries are just wires no circuit boards between them.

yes if one alternator goes out it will still charge.

you should always change both batteries at the same time. One new battery and one old battery means soon two bad batteries.

Always cheaper to add now then later.
 
Did a lot of research into this myself. Didn’t spec it in my order. Unless you plan a winch, or plow, a stadium’s worth of lights, or something similar then they literally serve no purpose.

Gotta draw the line somewhere on the “well it’s only $XXX so I’ll add it” logic or you end up with a $75K XLT or a $95K Platinum.
 
It's the one feature I wish mine had. I'd like the extra alternator capacity for when I have the camper on. My truck also sits sometimes for a couple weeks at a time so I'd like the extra battery capacity.
 
Did a lot of research into this myself. Didn’t spec it in my order. Unless you plan a winch, or plow, a stadium’s worth of lights, or something similar then they literally serve no purpose.

Gotta draw the line somewhere on the “well it’s only $XXX so I’ll add it” logic or you end up with a $75K XLT or a $95K Platinum.
My 7.3 lariat was $73k sticker ?
 
I personally like the integrated winch.

Batteries are just wires no circuit boards between them.

yes if one alternator goes out it will still charge.

you should always change both batteries at the same time. One new battery and one old battery means soon two bad batteries.

Always cheaper to add now then later.
Good info.
yes always change both batts at same time.
 
i went with the dual batteries and the 397 amp alternator since i was doing the upfitter switches knowing i wanted to run extra lights (and whatever else along the way) — same with what others are saying ... cheaper to add it in the order now than doing it later. i knew i wanted a higher outputting alternator so that pushed the dual battery issue for me.

sidenote: i have a WELL optioned 7.3l platinum 250 and my invoice was $72k.
 
i went with the dual batteries and the 397 amp alternator since i was doing the upfitter switches knowing i wanted to run extra lights (and whatever else along the way) — same with what others are saying ... cheaper to add it in the order now than doing it later. i knew i wanted a higher outputting alternator so that pushed the dual battery issue for me.

sidenote: i have a WELL optioned 7.3l platinum 250 and my invoice was $72k.
The only choice with two batts from factory is dual alts on the 7.3 gas correct??
 
So the standard no-option alternator is 240A. Is that just one? Does the 397A option get you two some how?
 
Excellent.
 
I looked into it.

On the 7.3 gas trucks, option code 67B 397-amp alternator gets you a 240A primary alternator, and a 157A secondary alternator.
 
I looked into it.

On the 7.3 gas trucks, option code 67B 397-amp alternator gets you a 240A primary alternator, and a 157A secondary alternator.
Yes. On mine one is clearly larger than the other.
 
I have the 7.3 Platinum with dual batteries and alternators. I plan on connecting the batteries to my Li-ion equipped truck camper via a dc to dc charger. I have heard that the second alternator never kicks in unless the first one has a large draw. anyone know how this works or how they can share the load? I am worried about burning out Alt #1. people on the camper forums have said this is an issue.
 
From what I read, the ECU switches the load between them quite frequently.
 
Good news. I know that with the dc to dc charger you can limit amps and time. So tentatively that will be my solution.
 
I'd like to see if I can drive a few more watts in the bed. It's not likely I'll get anywhere near the F150's 7.2kW, but it would be nice to power some higher power components like running the air conditioner in the travel trailer. If it takes 15A at 120VAC, I'd like to be able to pull the necessary 1800 watts minimum without impact to other systems, and the more the better obviously.

I'm also going with the dual alternator setup for a 397A total, so thanks to the poster who mentioned it's a 240A + 157A. If there is room, I'd like to swap out the 157A alternator for a 350A one such as https://www.motorcityreman.com/ford-high-output-hi-amp-hairpin-alternator.html.

That 197A increase at 12VDC is 2364 watts, which meets my requirements above and beyond the upgraded stock power. And since the winch was the reason that stock power had to be upgraded in the first place, I'm expecting to have a lot more watts available when the winch isn't running so maybe I can run a TV or coffee pot too.

Thoughts?
 
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