Dual Alternator setup for 04 Chevy Express?

[rauscs]

Has anyone had luck installing a dual alternator system in a 2004 chevy Express? 04C190P. What I've seen is 2006 and on.
Thanks!

[rowiebowie]

Have you considered just installing a heavy duty alternator in place of your stock one?

[booster]

I think a 2004 will be the same as the rest of the Chevies of that generation. Probably best to check with Nations Starter and Alternator to see for sure as you would likely be getting it from them. Not a simple or overly hard to put in but does take some disassembly of stuff to do and probably want to move the mountings for the dipesticks a bit.


With a 2004 you will have a better choice of how to do the wiring as you don't have a PCM controlled alternator in it. The wire to the PCM is just a signal of load and doesn't get controlled. This allows you put both alternators on a single remote regulator in parallel if you want. You can also put in the second alternator as a standalone on an internal or external regulator depending on you battery type and preference. We run our 2007 setup parallel.


What are you looking to get for benefit and use from the second alternator?

[rauscs]

I've already added a high-output alternator, but it is not providing as much output as I was hoping. I've got another thread regarding that:https://www.classbforum.com/forums/f...90p-11671.html. I am playing phone tag with Nations on causation. Looking again at a dual setup, but not finding kits.

We've got 3 Lifeline 125AH AGM's, and the original alternator took forever to charge them (still happening with the high-output alternator).

I did talk with Nations, and their kit starts at 2006. I've seen that at other providers as well.

Thanks!

[booster]

Originally Posted by rauscs

I've already added a high-output alternator, but it is not providing as much output as I was hoping. I've got another thread regarding that:https://www.classbforum.com/forums/f...90p-11671.html. I am playing phone tag with Nations on causation. Looking again at a dual setup, but not finding kits.

We've got 3 Lifeline 125AH AGM's, and the original alternator took forever to charge them (still happening with the high-output alternator).

I did talk with Nations, and their kit starts at 2006. I've seen that at other providers as well.

Thanks!

I was in on that thread and I thought it was taken care of. Have you gone down to 50%, which is of no hazard to your batteries, to see what the charge rate is there. As soon as you try guess at what your rate should be in the higher than even 65% full, you will likely be wrong. On our 440ah Lifeline setup we would charge at 180 amps, which is .4C, until not even 70% full most of the time and then it would start to taper. By 80% it was very much lower than 180 amps at well under 100 amps and by 90% dowon in the 20s amps.


Until you get a recharge from 50% so looking for around 190ah down from totally full (us the amp hours because we don't know at this point if the % SOC is accurate because of settings and getting a reset at full.


I would take them down to about 12.3v after no load resting for a few hours and then start you recharge at 1404-14.6v in absorption and look at the amps after about 5-10 minutes when initial inrush is over.


I would not invest in a second alternator until you do this test if it were mine to do.


What amps do you think you should be getting?

[booster]

This should be the kit for a 2004 van unless there was some change in the vans that I haven't heard of.


https://www.nationsstarteralternator...k-3992v-i6.htm


I don't know why they list it for only 2006 and up as the change in system to PCM controlled came in 2008 and those and higher have to use it as a standalone alternator not parallel.


There probably is someone on the forum that has added one to a pre 2006 model though.


Be aware that an internal regulator if you go that way will not charge in absorption long enough to get totally full on an AGM, and neither will a Balmar. Getting totally full on lead acid batteries is very difficult unless you can lock in absorption longer.

[rauscs]

Thanks Jim, I'll take it down to 50% and see what happens. Keep you posted.

[rauscs]

Got some data. Brought SOC down to 48%, left it with no load overnight, and did some testing this afternoon. Attached is a PDF with the data. Max alternator output was 150A, rapidly tapering down. First test was 12:40 to 1:20, then our dog had a vet appointment, so I stopped. Restarted later in the afternoon. Hopefully this data makes sense - I'm not sure what's up with the total alternator Amps vs House Amps...

The Charge# vs AH required to 100% ("AH" on the trimetric) #s seem to pencil out right with the 375AH AGMs. In other words, the trimetric seems to be calculating the %Charge correctly.

The alternator is not putting out the juice I expected, even with 50%
charge to start.

Might see if we can move the last portion of this thread over to my first one: https://www.classbforum.com/forums/f...90p-11671.html.

Appreciate any and all feedback!