mws,

I will look into the Odyssey batteries when my new yellow Optimas pack it in. I have two new units still in the shipping plastic waiting to be installed. I was atleast able to get a pair with one digit out on the serial numbers as was recommended to me at one point awhile back.

I'll have to look into the Wrangler tray for fitment with the Odyssey batteries. I have a feeling that they might not fit too well in my application.

Rick...

 

BTW I've been looking at MechMan alternators.

MechMan.com - High Output Alternators, AGM Batteries, 12- & 16-volt Charging Systems for Car Audio

They say they put out over 165 amps at idle (on a V10) and need around 1600 RPM for the full 270 amps.

 

13.4 to 13.6 volts indicates the charging system is likely keeping up with the load and you're probably OK.

The best way to know if you're going negative is to:
1) Drive a while with normal to lower electrical loads, or better yet, put on a charger until battery is fully charged.
2) Let sit an hour or so with truck turned off and NO loads. This allows battery to stabilize.
3) Take a voltage reading right off of the battery terminals. Call this value your "charging reference voltage".

As long as the (engine running) voltage is higher than that, the charging system is keeping up and is likely also able to recharge. If voltage drops below that, you may be in deficit mode.

I say likely and maybe because how/where you measure voltage will cause measurement error. Ideally, you want to monitor right off the battery post with dedicated wires to the voltmeter. Worst case is to tap into a circuit with minimal wire size and other heavy loads - the heavy loads will cause a voltage drop in that particular circuit so it is no longer indicating battery conditions.

Assuming you are monitoring right at the battery terminal: After a heavy deficit load (like cranking the starter or running winch under heavy load), the alternator voltage should go up well over 14V as it is working hard to recharge battery. As battery tops off, voltage will drop down to right near 14V. The exact values vary depending on the aforementioned where you monitor bit and your particular regulator (some run a bit higher, some a bit lower)

 

Absolutely use the Optimas for now. They will likely last many, many years.

Tip: If you can't fit the extra Optima under the hood, look under the truck bed! There is enough unused space under there to stash at least a half dozen extra batteries.....
Just keep in mind that the rate at which batteries can absorb a charge IS very temperature dependent so a battery mounted outside the engine compartment will charge slower. Much slower if under 50 degrees F or so.

 

Another option for ultra-high output alternators:
6G Series Heavy Duty Bridge Rectifier High Output Alternator

This is where I got my 250 amp GM unit. I went with these guys as their primary focus is high output AND high reliability. I recall they started out by designing/making stuff for ambulances and other emergency equipment. Some of the high output stuff for the audio crowd is more about bling than good robust design.... The dual rectifier alternators and "quicktifier" external HD rectifier are examples of smart design.

 

The 6G Series 250 Amp, Heavy Duty Triple Bridge Rectifier with Quicktifier 420 Option Attached (bottom of page) was and pretty much still is at the top of my alternator list. I've been eyeballing them for a few months, but by the time it gets to my door here in Canaduh I'd be looking at around $650.00 to $700.00 CDN. Ouch...

Rick...

 

Mike,

I can't seem to find any info on what they have for the 6.8? All I could come up with was call them for info when selecting the Lightning 6.8.


Rick...

 

I found it under this link.

MechMan.com - High Output Alternators, AGM Batteries, 12- & 16-volt Charging Systems for Car Audio

I also gave them a call and they said that they have them avaliable for the V10.

 

Ayyyup! Kinda makes your wallet bleed.... But personally, I've found alternators are one of those areas where you get what you pay for.
An alternator failure can interfere with the fun factor on a trip - especially in the back country. If your existing one still works, tuck it away in the truck as a spare (bag it and ziptie/strap somewhere under the hood?) and then you can take a lot more risk in selecting a lower cost unit as reliability is not such a critical factor. Lucky for us, these are relatively easy to change.
If you don't want to carry a spare, well, better consider a band-aid for the wallet!

 

Damn Rick... payback is hell! Now I have another mod added to my wish list!

 

And for my fellow DIY crazies, you can get a Stancor 586-902 contactor for about $50 from a number of distributors. I have purchased through Mouser.
http://www.stancor.com/wrdstc/pdfs/C.../Pg_056_57.pdf
If you notice, it looks very similar to the one in the Painless kit!

It does NOT include any of the instructions, switches, wires, or connectors you get in the Painless kit so whether you're better off using the kit or piecing together your own depends on your access to necessary supplies and electrical knowledge.

 

Andrew,

I'll consider it "even" when I get atleast $1650.00 USD total added your wishlist. Maybe $1200.00 with the "dual stabilizer discount".

Rick...

 

The Stancor seems like a terrific option to save a few dollars. I would think using the Painless installation Instructions/PDF would prove helpful with a home made kit.

Rick...

 

That would explain the digital voltmeter showing a slightly lower voltage than the ScanGaugeII. I have it (the digital gauge) tied into the main power lead to the headlight switch along with an auto dimmer lead.

-----------------------------------

I have a CTEC 7002 semi permanently mounted in the truck so I will run the test this weekend just for the sake of doing it, but,,,
There's been several times I've watched both gauges after sitting with the stereo and other accessories on while the is engine not running. I've noticed the voltage jumping to approx: 14.4 / 14.5 a few times just after starting the engine and keeping it at idle with all the accessories off. It would take a minute or so to slowly drop to around 14.0 / 14.2. After turning accessories on (still at idle) it would drop to around 13.9 / 13.11 depending on the accessories used.

I'm feeling confident the alternator is doing it's job pretty well.
I like the idea of installing a new higher output alternator and keeping the used unit as a spare for the backroad trips, but it's not as easy for me to replace the alternator as a sock 6.8. It's a bit of a bugger for me with the blower ontop of it, but of course in a pinch it's a doable swap if stuck on a mountain top.

Rick...

 

I browsed thru the posts, I dont know if its possible but you seem to be trying to reinvent the wheel.

Can you not use the duel alternator setups or the Bigger Alternators that the diesels have?