Battery and Alternator Questions

Thanks guys. I will try the interstate battery this time. It's much cheaper too.

I would say it is probably the battery starting to go bad.. The battery seems to drop voltage once you start the car and go back up once the alternator kicks in.. I love the deep cycle batteries, but as far as I know trickle charging a deep cycle is probably the downfall to them. Everyone that hates them seems to be a person that puts a maintainer on them.. Deep cycle batteries do not need battery maintainers..Lead Acid batteries do..

ive kept optima on battery tender without problems...

Just to clear up the battery thing. Deep cycle, starting, gel, AGM. They are all lead acid batteries. Deep cycle batteries are designed to deliver lower currents for long periods of time, while starting batteries produce high currents for short periods of time, which is what you want in a good starting battery. Optima's, and others claim to do both, and they can, but it comes with a compromise in performance in both departments. Also, weight is still king in lead acid batteries. The heavier, the better. If a light weight lead acid battery claims to preform as well as a heavier lead acid, it's not true.

 

That's just a few facts. It's my business guys, so I'm not just spouting off about something I read.

Just to clear up the battery thing. Deep cycle, starting, gel, AGM. They are all lead acid batteries. Deep cycle batteries are designed to deliver lower currents for long periods of time, while starting batteries produce high currents for short periods of time, which is what you want in a good starting battery. Optima's, and others claim to do both, and they can, but it comes with a compromise in performance in both departments. Also, weight is still king in lead acid batteries. The heavier, the better. If a light weight lead acid battery claims to preform as well as a heavier lead acid, it's not true.

 

That's just a few facts. It's my business guys, so I'm not just spouting off about something I read.

 

Thanks for the info. So which would you recommend for exotics with low useage?

I like the Interstate MT34 for our cars. The Optima's have more mixed ratings surrounding them than conventional batteries. So while one person may have good luck with them, the next guy doesn't. This applies to more than just automobile use. There is no such experience with a good quality conventional battery such as the Interstate. Admittedly, it’s kind of hard to know what your getting with all the private labeling and, off shore manufacturing, just like everything else Today. Still, if you stick with one with at least 700 Cold cranking amps, comparable weight, and that will physically fit, You will have good results.

 

Another thing to consider with the the premium priced Optima’s, your paying for features like being able to mount it in any position, and vibration resistance, none of which are important to street cars. If you still want to stick with the Optima, I still suggest the RED top, a more pure starting battery.

 

Disclosure. I do not sell batteries or have any connection with any brand, and of course use a maintainer.

Ok.....Update.

 

So since the issue was still happening with the new alternator, I figured the only other thing to replace would be the battery. So I just put in an MT-34 Interstate to replace the Optima Red Top. And.....

 

 

 

 

SAME THING is still happening. I'm no electrical engineer but this is pretty puzzling to me. What other than the alternator or battery would be affected and be bumping the voltage up about 2 volts due to hitting around 3000 rpms?? The belt isn't loose. I did just replace the post to battery positive wire since the other one was crap. The only possible thing I can think of doing now would be to replace both positive and ground wires running from the alternator. Anyone else have any ideas or thoughts? Jeff?

 

I mean the car still cranks up and drives fine and all but it just annoys me!

This kind of guying off topic, but what are the symptoms for a battery that's dying?

 

Chipster ... could something be turning on like the A/C that is causing the change in voltage? Also, where exactly are you measuring the voltage? Maybe a few of of us could do the same test to see if we see the same results.

My A/C isn't even hooked up. At accessory position and initial crank, the gauge reads about 10 volts. On the battery itself, the voltage is about 12. Then once I am driving or rev the engine to about 3k RPMs the battery will read close to 14 and the gauge in the car will read about 12. And it will stay at those levels the rest of the time driving. Next time I crank up, it's the same thing. What bothers me is the 2 volt change, not that the battery gauge is reading less than the battery.

 

Lol, at least I know I have a good alternator and decent Optima battery I can sell now!

On the battery itself, the voltage is about 12. Then once I am driving or rev the engine to about 3k RPMs the battery will read close to 14 and the gauge in the car will read about 12. And it will stay at those levels the rest of the time driving.

 

How are you directly measuring the battery? I can't remember if you stated you had a maintenance charger plug installed in the wheel well, so are you justing connecting the volt meter to the maintenance charger plug?

Nope. I had the wheel off and the wheel well portion covering the battery off and was measuring directly at the battery terminals. I do have a battery maintainer connected as well.

That sounds like a lot of work to measure the terminals ... next time I start the car I will have someone check the voltage via the maintenance plug connected directly to the battery.

That sounds like a lot of work to measure the terminals ... next time I start the car I will have someone check the voltage via the maintenance plug connected directly to the battery.

 

I had the wheels off anyways when I was putting on the "new" wheels. Thanks!