Dead battery, I'm done with Optima!

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moviewithnotitle

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Late last week during a good cold snap here in NJ, I went to start my Tahoe and she was dead! Stone dead. Hooked up the charger at 10amps/manual and left it for about 25min. This should have been enough time to get enough charge to crank her up, but nothing. I got good lights and everything else, but the starter just gently ticked and then nothing. After some old school cussing, I jumped her with one of my other vehicles, fired right up. Left her run and ran back inside. Talked to the wife for a while, played with the kid and then headed to work. Truck was running for a solid 1 hour. After work, she cranked but it was slow weak, but she got going. I have noticed that since the summer too, that the battery has been slower and weaker than normal.

I have been a fan of Optima batteries for a long time, my first was in 1999, and have run them in my cars and boats. They are great batteries. But the Tahoe though has killed 3 in the last four years. The first was a Yellow top, that lasted 8 months. Got warranty on it, and it was good for another 15 months, then died. After that I got a Red top which is exactly 2yrs old now and it's on its way out. Previous to this I had an Interstate Group 78. It was about 6 years old when I replaced it and worked well but seeing it's age, it was time.

I have throughly tested the charging system and wiring at several points in the vehicle and all checked out OK. I have also upgraded the grounds and power in several places over the last year so I am confident this is not the issue. I have tested for Parasitic draw on the vehicle a few times and never found anything that would be of concern, which all leads back to the battery.

When the battery is at rest, it sits at 12.45v. after a short time it begins to drop voltage and will level out at 11.35v. I noticed a bulge in the case under the sticker, usually an indicator of something bad happening or has happened in the past.

Again I really like these batteries, but in this vehicle I am at a loss.

So here is what I am planning on doing.
1. Going to replace the current battery with 2x Interstate MT-78's. (I have been planning for a 2nd battery when the funds were available, already got the 2nd tray installed)
2. Install a Hellroaring BIC8000 series Isolator combiner. (I use this unit in my boat and it's flawless. Has also saved me a few times out on the water)
3. Move all non-essential electrical items to 2nd battery. (Not that I have very much, but Stereo, Emerg Strobe lights, Aux/Backup/trailer lights, Scanner and 12V constant plug in the interior.
4 (possibly) Upgrade Alternator to the 140amp unit. (depends on how everything looks after 1-3)

With these 3 mods I should be solid. And with the great warranty on the Interstate's I should be set for a while.

I'll post a new thread for the install of all this stuff when I finally source all the parts and get around to doing it.

That's my story and I'm sticking to it!
MWNT
 

drowndindreams

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interstate tops are badass... im running the mt 78, only had to change it once in two years because I drained it with my system.
 

retorq

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I had the same issue in my 86 Blazer a long time ago. It wasn't the battery, changing to better (higher quality/bigger) main power and grounds was what finally fixed it. I also added multiple grounds, one from each head to the frame, and the battery to the frame. I think running dual batteries will only prolong the time between "bad batteries" for you. Either way, good luck, it took me a while to figure that out on my own.
 
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moviewithnotitle

moviewithnotitle

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Yesterday I picked up 2 MTP-78's. one of them even had top posts which works for my setup. The other is just side terminal. Got the main battery installed last night before the storm hit jersey. I'll get the 2nd battery installed this weekend with a relay and start moving some wire over to it.

So far all is good. Voltage Gauge is reading much better, but I suspect that I need to replace a few main wires still. The Main starter wire and the feed to the Relay/Fuse box under the hood. I am still seeing some anomalies that I don't like. Considering upgrading the alt to a 140amp as well. I have never felt that the 104amp was sufficient based on research and talking with people in the past. IMHO it should have been a 120amp or higher from the factory.

retorq,
Intersting info, I will look into that, but I suspect that I'm not that bad off. Just older wires and grounds. I have done the Big3 (plus a few others) already, I think I just need to delve further into it.
 
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moviewithnotitle

moviewithnotitle

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Well with the 2nd battery install, I came to realize that the Alternator was not in good shape as well. My past experienced has always showed they tend to be connected in failure. The Alt was pumping out 14-16.6V. Anything above 15 is danger for a battery over time. Regulator was bad so in went a new Alt with the battery. Upgraded the Fuse panel feed from 8Ga to a 4Ga wire as well.

The system is ROCK SOLID now...finally.
 
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BigDaddy13440

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Well with the 2nd battery install, I came to realize that the Alternator was not in good shape as well. My past experienced has always showed they tend to be connected in failure. The Alt was pumping out 14-16.6V. Anything above 15 is danger for a battery over time. Regulator was bad so in went a new Alt with the battery. Upgraded the Fuse panel feed from 8Ga to a 4Ga wire as well.

The system is ROCK SOLID now...finally.

With the second battery install, did you run an isolator, or just run them in parallel?

My dash gauge always shows <14v whenever I run my system at even 1/2 volume, I can watch the lights and gauge dip as soon as I turn on the heater blower or the wipers. I'm only running amps rated at just shy of 900 watts total, nothing compared to some guys running 4K and up with 4-5 (or more) batteries.
I'm looking to do the upgraded alternator too, probably going with at least a 180amp unit. Already have the Big 3 done, multiple grounding points with 1/0 wire.
Do you think that replacing the 8ga feed to the fuse panel with a 4ga feed made a difference?
 

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