Electrical upgrades? Suggestions?

[mfry]

I'm working on upgrading electrical for installing a pretty serious set of subwoofers in my 2004 LS 3.9. I have a 320a "hairpin" alt from JS alternators, and I'm putting together a large lithium bank from used cells to hold the power because AGMs will be too heavy for what I need. I was working on using a lithium chemistry that would work with the standard charging voltage, but it's becoming a hassle to find cells that are not weak. Another option would be to "delete" the trunk battery and switch to a slightly higher voltage lithium chemistry I can get new cells for. A lot of other people do it in many other vehicles. Trucks, cars, jeeps, and whatnot. But I would have to bump the charge voltage up to minimum 15.5 preferably 16 and I'm worried it could cause other electrical issues with the car..
I don't think I should go that route, but I've been lurking on the forums here and decided to go ahead and see if anyone has any insight or suggestions.

 

[04_Sport_LS]

You are fighting the PCM because it controls the alternator voltage.

To the best of my knowledge nobody makes a high output Alt for the LS.


Again... the PCM controls alternator voltage... and amperage.

 

[mfry]

From what I heard only gen 1 is pcm. Gen2 is internal.

 

[mfry]

I can make it charge at 15.5v. I was just wondering if it would create any adverse issues

 

[04_Sport_LS]

Pretty sure Gen 2 is PCM controlled.

Depends on what you consider "adverse".

Short alternator life???

Keep in mind the alt on the V8 is a pain to change out.

 

[joegr]

Pretty sure Gen 2 is PCM controlled.

Depends on what you consider "adverse".

Short alternator life???

Keep in mind the alt on the V8 is a pain to change out.

Nope. Gen 1 was PCM controlled, gen 2 is alternator controlled.
The higher voltage will kill the MOVs in the electronics, such as the SRS module. It will take repeated exposure, so he will think he has gotten away with it for a while.

 

[mfry]

I haven't done it yet. That's why I was asking in here, because I know these Lucas designed electrical systems are finicky. Now knowing that if I were to decide to go that higher volt route I would have to run the alt separately to the lithium directly and run quite a few XS power step down modules to the rear battery to keep it charged. But since that's just too much of a pain I'll stick to the Lifepo4 lithium I've been fussing with and the factory charge voltage, and just deal with it..
I figured it would probably kill something in the car that's why I asked here first before switching the alt regulator out.

 

[oddball]

Normal car charging is 14.1V. The nearest common rating for DC components is 15V. I wouldn't go over 15V and you want to stay well below that because its the surges/spikes that quickly kill things.
Higher voltage probably won't really help you. Keep the voltage low and the amps high and have supercaps or similar close to your equipment to help with momentary high draw.

 

[PizallWízall]

Hey mfry, how is that js alternator working out for you? I ordered and received one last year and the bolt pattern was off. Not to mention it took almost a month to get that one. They never could figure out what I needed even after I fax them all kinds of info on the stock alternator. After about 2 months I finally got my money back. I have 2005 LS V6, not sure if it is the same alternator as the V8. Curious what kind of experience you had with js alternators.

 

[joegr]

...I have 2005 LS V6, not sure if it is the same alternator as the V8. ...

It's not. The mounting is very different.

V8

V6