My 2007 Tahoe EATS Optima AGM batts!

[Streborel]

Are Optima Yellow Top AMGs not appropriate for a 2007 LTZ? I installed a second auxiliary battery in my Tahoe with an auto-isolator that opens when the engine is not running so that I don't drain the original main battery. But since the batts ARE connected when the engine is running I had to install an identical battery as the new Aux Batt (I already had an Optima Yellow Top installed as the main battery) so that both batteries would charge equally. I drive her very little, maybe 1000 miles/year but I keep a battery charger/maintainer connected to the Main Battery. The Main Battery gets weaker and weaker and I've replaced it twice in 4 years and now is dying again. My question to you is = Is there any reason why AMGs aren't proper for my 2007?

 

[swathdiver]

Are Optima Yellow Top AMGs not appropriate for a 2007 LTZ? I installed a second auxiliary battery in my Tahoe with an auto-isolator that opens when the engine is not running so that I don't drain the original main battery. But since the batts ARE connected when the engine is running I had to install an identical battery as the new Aux Batt (I already had an Optima Yellow Top installed as the main battery) so that both batteries would charge equally. I drive her very little, maybe 1000 miles/year but I keep a battery charger/maintainer connected to the Main Battery. The Main Battery gets weaker and weaker and I've replaced it twice in 4 years and now is dying again. My question to you is = Is there any reason why AMGs aren't proper for my 2007?

The charging system was not designed to charge AGM batteries, they do not like to be charged above 15 volts which our system will do when the occasion calls for it. Batteries still have to be the same and replaced at the same time and charged together to get the most life out of them.

 

[j91z28d1]

15 volts is definitely to high for an agm. but also isn't the yellow top a deep cycle or something different then the red top cranking battery?


my question is why isn't it killing both batteries, just the main battery. since you don't drive much and it disconnects the 2nd while sitting. are you using a maintainer on both batteries? if not and just the main battery, you might want to try a Optima charger/maintainer. while they are afm, they are a bit different with a spiral wound cells. sounds to me like you're over charging it while parked more than while driving.

 

[Streborel]

I have used several different chargers. But I JUST ordered an Optimate7 TM=263 from Amazon. I'll try this and see how it works. Thanks bunches.

 

[petethepug]

It’s not just you or GM trucks. Since Optima stopped using virgin lead in their batteries after Johnson Controls bought them they’re short lived.

I just ordered an Odyssey AGM battery for our 09 from Walmart online w/free shipping. They’re the only company using pure, virgin lead now.

 

[mikez71]

The odyssey AGM battery says is uses 99.9% pure lead.
However, their AGM^2 battery does not say lead, but high density plate oxide.

Sounds like their AGM battery is the way to go (Commercial/truck vs Car).
~2x the cost of my ACDelco batteries, which are not lead.

Thanks for the tip.. How long before lead isn't available anymore?

 

[swathdiver]

The odyssey AGM battery says is uses 99.9% pure lead.
However, their AGM^2 battery does not say lead, but high density plate oxide.

Sounds like their AGM battery is the way to go (Commercial/truck vs Car).
~2x the cost of my ACDelco batteries, which are not lead.

Thanks for the tip.. How long before lead isn't available anymore?

Huh? I just read several articles that says they use a majority of recycled lead. One plate is lead, one plate is lead dioxide in each cell.

With the recent changes in Washington, I reckon it won't be long before lead starts being used more often again with less red tape.

 

[Scrappycrow]

My 2007 Tahoe EATS Optima AMG batts!​

... AMGs... AMGs...

For the sake of folks who search on titles, would you mind correcting at least the title to "AGM," please?

 

[Fless]

For the sake of folks who search on titles, would you mind correcting at least the title to "AGM," please?

Thanks for pointing that out; Mercedes must have been on his mind. I updated the title.

 

[Coveman]

I haven’t had good luck with trickle chargers (even the newer nocos) they tend to fry the battery. Better to unhook the battery and charge it every month or so.

 

[swathdiver]

I haven’t had good luck with trickle chargers (even the newer nocos) they tend to fry the battery. Better to unhook the battery and charge it every month or so.

We have a guy on here who's been to Trickle Chargers Anonymous and knows the good ones. Mine has only helped and never hurt and it is a Battery MINDer 1510.

 

[Coveman]

That’s nice. For stuff that I dont drive for months at a time they all seem to create battery ‘memory’ that ruin the battery after a year or two. With the battery disconnected they hold a charge for months

 

[j91z28d1]

the ctech on mine seems to have gotta the optima in my other car to last for years without being a daily.


if you're eating thru 200$ car batterys every year or so at some point you'll have spent as much as just buying the orange top that turns itself off before it dies, so you can't kill it. plus it weights about as much as an empty plastic case haha.

 

[swathdiver]

That’s nice. For stuff that I dont drive for months at a time they all seem to create battery ‘memory’ that ruin the battery after a year or two. With the battery disconnected they hold a charge for months

My kids once accidentally drained a 3 year old battery down to below 9 volts. I hit it with the 50 amp charger on and off for several hours until it got up into the 11 volt range and then put the 1510 on it. It lasted another year. When it acted up again, I could have put the trickle charger on it but didn't want my wife and children stranded and it was already 18 months past its useful life.

He hasn't been on in over a year but this is the guy who is an expert on them if you care to do a search: @Spoolin

 

[Charlie207]

It’s not just you or GM trucks. Since Optima stopped using virgin lead in their batteries after Johnson Controls bought them they’re short lived.

I just ordered an Odyssey AGM battery for our 09 from Walmart online w/free shipping. They’re the only company using pure, virgin lead now.

My ODY-48720 Group 48 H6 Battery (purchased Dec. 2022) is still going strong. Knock on wood!

I also bought one of these about 2 years ago, and it seems to work. I've got two spare (used batteries) for my crappy plow truck, and I've let them marinate on this thing for a few days at a time to let it do it's magic.

INFO:

About this item​

• Advanced 5-in-1 Device - Starts, charges, maintains, tests, and reconditions batteries
• Immediate Charging Power – Delivers 100-amp engine start, 30-amp to 12-amp boost charge, and 6-amp to 2-amp charging
• Smart Trickle Charge - Maintains 6V and 12V batteries safely over time without overcharging
• Wide Compatibility - Works with gas and diesel vehicles, 6V and 12V batteries, including standard, AGM, gel, and deep-cycle battery types
• Battery Reconditioning - Helps extend battery life and improve performance with advanced desulfation mode
• Built-In Battery and Alternator Tester - Quickly checks alternator and battery health for easy diagnostics
• Reverse Polarity Protection - Prevents damage to your battery and vehicle if clamps are accidentally reversed

 

[Jolly Roger]

I had dual AGM batteries in my 07 Tahoe and had no problems after a little experimenting. I found that the AUX batt wont get a good charge with loads running if you dont have the dual battery system hooked up correctly. Your Neg battery cable has that PITA hall effect sensor on it that monitors loads sending signal to ECM and then the alternator dishes out voltage per demand. The system will fluctuate from 13-15 volts. (Optima batteries are happy with 13.8-15 volts). Most AGMs need a bit more anyway, usually an average of 14.4v

BEFORE I go further, Ill just say I believe your problem lies with the Battery brand. They suck.

Now to the argument that exists all over the web about how to properly install a dual battery system in a vehicle with a smart alternator/hall effect controlled charging system...
---------
Do you connect the ground of the second (AUX) battery to the ground of the vehicle bypassing the hall effect sensor?

OR..

Do you connect a separate ground lead all the way back to the main battery?
----------
Some claim that by connecting the AUX batt directly to ground, your system sees the second battery as a load and all is just fine and dandy with having just your main battery on the hall effect sensor.
Some claim that one must run a separate ground cable back to the main battery so that the only ground cable that connects the two batteries to the chassis has the hall effect sensor monitoring both batteries as one big battery...

I tried both ways and found that I never saw 15v (which is normal under load) with the AUX battery hooked directly to the chassis. The AUX battery voltage was always low.

When I connected a separate ground all the way back to the main battery I saw 15v like I did before adding the AUX battery and my AUX battery was now getting fully charged.
I left it that way and never had a problem. I ran it this way for almost 5 years.

One of the other arguments was that the dual battery systems on the diesel trucks utilize a system where the AUX battery hooks directly to the chassis. But if remember correctly (its been awhile) the diesel trucks didnt have a hall effect sensor to begin with.