04 dodge ram dual alternator setup

I presume this system is totally independent of the existing alternator and (primary) battery except for a common earth/chassis?

The head unit (presumably powered from the second battery) could then merely switch on a relay that supplies power from the 2nd battery to the meters and the 2nd alternator - ie, its (regulator's) Ig terminal or if a D+ terminal only type, via a 2-3W "charge lamp".

The second battery is then permanently connected to the 2nd alternator's output (B or B+). (Maybe via a 250A fuse (LOL?)which is only to protect any shorted 2nd battery wiring, and allegedly the 2nd alternator's power diodes from reverse battery connection (LOL#2?).)

And you must have a charge lamp to ensure the alternator begins to charge.

Is that what you want? IE - The second alternator only supplies power and charges the 2nd battery when the head unit is on.

I'd recommend NOT having the ammeter unless it serves a specific purpose. And if regulation or voltage is critical, I'd consider a Hall Effect meter instead of a shunt ammeter.

But maybe you could explain your metering need, and why a variable voltage regulator is required. (Also what type of 250A alternator - whether 1 (D+), 2 (S&L or Ig&L) or 3 (Ig, S, L) wire internal regulator etc?)

If you are paralleling the 2nd alternator to the first, count me out - I'll leave that for others....

Hi Cezar,

You say you aren't an electrician and have only knowledge of the basics, yet your comment "I really only need the voltage display" is so profound! (IE - a voltmeter tells you everything; an ammeter is useless - it only tells you what current you are using, but not if it's enough, or at a bad voltage.)

You are also correct re the "2nd ground" - that's what I meant by "independent .... except for a common earth/chassis". Alternators are grounded through their casing and hence share their common ground with the engine block, vehicle chassis, and battery negative terminal.

And that reminds me - the Big-3 - you must have ample engine to chassis ground! Add a second ground wire from the engine to the chassis to handle the extra 250A. (Rather than replacing any existing ground cable, a second adds some redundancy. Besides, I like the method suggested on this site - ADD an extra ground/earth strap/cable - not replace it; this should prevent warranty etc issues with manufacturers.)

I'll see about getting some diagrams together (and posting them - I'm still a noob aka Rookie).

This may be above my head, but oldspark, you ain't no rookie! Keep posting, secondly can't this all be a acccomplished with a decent quality split charging system?

Thanks Howie!
Alas Rookie hereon means up to 50 posts until I can post diagrams which I think is a bit excessive, but I didn't expect to be this active (this being my 28th post).
Though I can't help thinking of my poor colleague who is far from a Rookie yet seems to be considered anything but.
But unlike me, he hasn't learned to NOT reply to moron sites!! (EG - after pointing out a certain wiring error, the best the knockers could reply was "so why is everyone else doing it?". Their other arguments were nothing more than confirmations of what he wrote or worse.)


But in answer to your split charging system - Yes.
However I'll qualify that....

Cezar's system is merely two independent systems systems sharing a common ground.
As I see it, he needs nothing more than to connect his 2nd battery via his fuse to the 2nd alternator and its load. (Noting that if only one 250A 2nd fuse, it is to protect the wiring from battery - the alternator should be self protecting and its wiring capable of withstanding at least 250A steady state - ie, rated at say 350A using a 70% loading rule).

Cezar merely needs an on-off switch to supply the 2nd battery's +12V to the 2nd alternator's external voltage regulator.
(And the 2nd alternator's voltage set as high as needed for desired output keeping in mind it should be sensing the 2nd battery's charging voltage where 14.4V is a normal "steady-state maximum" and 13.8V is the normal "float" voltage - depending on the battery, and how long you want it to last lifecycle-wise.)

It should also be possible to charge the 2nd battery off the primary alternator & battery circuit by using a common "charge lamp" circuit (off the primary alternator.... obviously....) PROVIDED the 2nd alternator is NOT charging the 2nd battery (because that would mean 2 alternators fighting each other).
IE - Cezar's "enable 2nd alternator" switch is powered from the head unit with a series manual "override" switch to power the 2nd regulator (probably via a relay to get full 2nd battery voltage to the 2nd regulator's sense input - presumably its +12V supply). The series override switch should be a changeover (SPDT) to interlock the "charge 2nd battery from primary alternator" - ie, so you can't charge (the 2nd battery hence everything off...) BOTH alternators.

As to "decent quality split charging system"...
I happen to agree with my aforementioned colleague that the split charging systems we have seen are a crock of bullsh aka spousetales (to borrow his jargon).
I too have seen systems that describe "charging of the second battery ONCE the first has charged".
Without going into the alleged logic of this, we are yet to see a system that current limits and treats each battery individually.
We both run twin battery systems where the second battery is paralleled to the first whenever the engine is charging, else it is isolated. (We both STUPIDLY used an overvoltage sensor to do this until we realised a much simpler method that merely required a simple relay!)

I have yet to see any argument against our method (excluding current limiting when the 2nd battery is smaller or of AGM etc type, but few of the "split charging systems" provide that anyhow.... let alone traditional primary systems!)

Anyhow, the final wiring diagram is somewhat dependent on the 2nd regulator's (and its alternator's) layout, but it is very likely to look much simpler than all the guff above!
I hope!

Let me know if I have committed the same mistake as my abovementioned colleague - and I do NOT mean mean "posting to morons" (!!!), but instead mean "treading on sacred ground" etc...
(Alas my dear colleague has just left a prominent site due to unqualified/unotified "censorship" of his posts. Not that he thinks profits nor egos should be protected, but he has limited persistence - and he enjoys a really good laugh "after the fact".)

Again, thanks for the compliment. I hope I haven't just blown it! (Come 50 posts and I may remove any offending parts!)

Very nicely put, Old spark! I sent you a drawing of what I believe MAY be correct as far as wiring already installed from the hood to the Bed.  For your review. Your feedback on that would be great. I really need to try and keep this simple. Simple and Efficient works best for me due to lack of experience. My purpose of keeping the (2) chargeing systems seperated is due to my thinking that my engine would appreciate if I didnt mess with its Alternator which I'm assuming was designed to handle the stock accessories it came with and not the 5k watts RMS I'm installing. Thats my logical guess. Besides, recognizing my own skill level at this I'd prefer to have these (2) systems seperated in case something starts to go wrong I would imagine it would be easier troubleshooting only the system which is giving the problems. Anyway thats my reasoning with the little bit that I know. I appreciate the replies and wait to hear from you.     Cezar

Dear Readers,

Help me out here...
Am I gullible, or yet again has this Cezar....

oldspark wrote:

---

You say you aren't an electrician and have only knowledge of the basics, ....

---

... fluked it yet again with...

cezarm wrote:

---

My purpose of keeping the (2) charging systems separated is due to my thinking that my engine would appreciate if I didn't mess with its Alternator....

---

... eh????

Yet again I am impressed at how an alleged novice's intuition is so spot on.... Namely that the reason for keeping two alternators separate is IMO because unless there is some sort of balancing, they will fight each other. (IE - if one adjusts to 14.2V and the other 14.3m or 14.21 & 14.22 etc; or they have different response times to changes etc etc.)

Isn't it funny how despite a lack of detailed knowledge, a novice's intuition can be so correct. Maybe that explains why many breakthroughs are made by people NOT in the particular field of expertise (like the first automated telephone exchange being invented by a Funeral Director, or aerated ice-cream by British Prime Ministers....).


I have received Cezar's email and we shall get back to you...

With apologies, but I suggested conspiring off-line with Cezar as I can't yet post diagrams....

But I intend that I/he/we post the final solution for the benefit of others. (Apart from courtesy, that's what these sites are all about. (Aren't they - or am I showing my gullibility yet again!?))

No oldspark, you are just being a nice guy.  This has left me breathless with the sorry story from a year of so ago of the *hole who phoned one of the shops I contract for with a quote to supply and fit a well known brand of alarm and R/S (it's name begins Cli) to his (probably) Clapped out (French cars are from new) Renault Clio. He booked in, didn't show and a week later he'd bought the damn set up from flea-bay and was asking installation advice. Talk about taking the food from my mouth!!!  That  sort of thing apart from my age and experience is why I'm rather cynical and I have been known to bite peoples heads off, especially if they a) don't listen, b) are SLAMS (stupid, lazy amateurs) or simply moronic, i.e. should you be doing this?  I often ask trick questions to test their knowledge and abilities before taking it further. I must also add that cezarm doesn't fit into the above categories and I would welcome his future questions though I don't get too involved in audio any more. As for you oldspark welcome to the small club of the truly knowledgable, electonics wise. Of which I'm the first to admit I'm not,  just loads of experience.

This is becoming a very interesting post. (Oldspark) My profession has been in the Welding Industry for the last 14 yrs as a Welding Inspector. I deal with amps and volts on a daily but thats about it. Just read them and check Welders parameters to ensure they are not running too hot or too cold. My lack of experience is a proven on this site dated from back around April or May of this year under the alarm security forum. Well, up to this day my posts never came to a closing chapter and I STILL havent got my Remote Start to work. Please dont get me wrong. I'm not trying to get off the subject that I started here. However, back then I might have fitted in the category of being a moronic, stupid, lazy amateur that didnt listen cause I stopped getting post replies from (Howie). (Howie) No hard feelings or grudges against you, I actually would like to thank you for your clues in helping me get my door locks and parking lights working. Just thought it would be important to express my perspective as a rookie being that my skill level was being spot lighted. I have no shame or feel bad not knowing something. But when people like (Old Spark) can give you an answer with the detailed reasoning (pros and cons) from his perspective. You got my respect. Not to mention Its nice to think we're ALL on the same page as hard as it is sometimes to communicate. I have to get back to installing an additional Ground. Thanks for all the comments and suggestions received so far.      Cezar

Well Howie & Cezar, I think I like this place.
I too dislike freeloaders - that needs to be balanced with a bit of giving.
And SLAMs - now I know why I like slam dancing (alas mosh pits are solo events these days - no more romantic couples or mates with judo holds bouncing like pinballs off human cushions).

I empathise with Howie.... I have great patience with the underprivelidged, and I understand bad reactions. But for the capable that do not listen, do not try etc - NO!. Especially when they add the bonus of personal attacks. (I like this site's rule - attack the idea - not the person.) That fellow mosher colleague I mentioned now tests out forums. He was asked by one admirer to join a particular forum. He was out within a handful of posts.
[He reluctantly joined having experienced a "circular discussion" with a prominent member, made worse that is was about a problem that didn't yet exist - and in my mate's opinion - never would. But his site test flushed out the non-arguing ability of some members & key players. Although the original inviter tried moderating, mate Peter decided to delay their 3rd chance until a time when he would be interested in what they could do (he felt he could do more quicker on his own and with other sources).]

And funny that Cezar is in the Welding Industry. Peter admired the above inviter and was ranting how he had met many toolmakers, welders and some other group (sorry, bad memory) and how they almost always impressed him - real good thinkers he said. (Peter's a qualified "professional" but he is rarely impressed with qualifications - to put it diplomatically!)

And that makes me think of Howie... not theoretically knowledgeable but lots of experience.... Aha! - when will we clash? LOL!
But that's a relief. I warned Cezar that I may lack the practical experience and therefore miss the obvious...
As to clashing, I used to love finding out WHY something worked the way it did - ie, finding the explanations etc.
I still do, but these days I probably prefer clashing theories & practices... Why the difference - opinion, or misunderstanding, or differing applications & aims?
Differing opinions are fine - they expand one's view. But to solve the misunderstandings or understand differing design intentions is both challenging & satisfying.

We'll see if we can close this post! Alas I/we seem to be padding it out but we aren't getting off subject...(?) ...it is nice padding isn't it? Ok - I hear a few readers dry-reaching - I get the hint.

As to older problems like remote starts - maybe later... But either a new post, though I'd prefer continuing on/from the original. (As I read it, that is against the rules, but if the original author continues on the same issue, it should be fine. IMO such rules are to stop 3rd parties reopening dead posts - it's better starting a new post - someone can always post a link to existing answers or old posts etc.)

As to unsolved posts, yeah - I felt many were still open. But I also noted relatively few that posted replies with solutions. And most of them seemed to have an "unobtainium" rating. Is it a coincidence that I already seem to recognise the main contributors - it could take ages or forever at other sites....

Anyhow, time for breakfast.
And to see if Cezar's diagram came through (I couldn't open it from his first email).

Oldspark, I resent the email as a jpeg and pdf. Hopefully one of those should work. Let me know if not and I can put it on the post reply. Thanks, Cezar

No probs.
I got the diagrams (pdf & jpg) and reply-emailed with a few clarifications/questions. (And a bit of FYI padding.)

And yes - I just checked - it was sent (~10 hours ago) and to your correct email address.

In short - I think you have all the required fuses or breakers (maybe to spare). I reckon a normal SPST else SPDT relay, a manual on-off switch, and an optional relay to charge your Aux batteries #2 & #3 from your original/primary alternator when NOT using your 2nd 250A alternator.
(But I didn't mention the voltmeter - but that could be permanently connected else relay connected with the above and/or manually switched.)
And BTW - all relays and switches are low power - ie NOT 250A, but merely 1 Amp if that - ie, common 15A relays are fine.