Hi guys,

i am fairly new to this so all/any help would be useful.

i have a Optima 55 battery and the problem is that everytime i really test my car on Termlab the battery starts to clip/cutoff.

The voltage drops from 14.4V to 11.8V. What can be causing this problem. My car runs on the IASCA format and does a 150.5dB in the Rookie Int. Class.

the car clips at 150.5. I am really eager to know what this could be.

Looking forward to your help guys.

Thanks.

Need to add another battery and/or get a bigger alternator.

My class limits me to the use of one battery only.

My alternator charges at 90amps.

We got to keep all the equipment standard in the vehicle.

get one big ass battery like a kinitic 2400.

get one big ass battery like a kinitic 2400.

Is there any way to resolve the problem using the same battery. Does anyone expirience with this battery

My class limits me to the use of one battery only.

My alternator charges at 90amps.

We got to keep all the equipment standard in the vehicle.

With only 90 amp alt, there isn't much that your car can power. That would be the best investment - a new HO alt.

get one big ass battery like a kinitic 2400.

Is there any way to resolve the problem using the same battery. Does anyone expirience with this battery

If you haven't already, do the Big 3. Won't cure everything but may help a couple 10ths of a volt. Should get the biggest battery you can fit under your hood.

What amplifier are you running? I would think you're using a pretty big amp to be in the 150s, I don't think you have near enough power to begin with. You're going to need a higher output alternator than you are running now if you don't want such severe voltage drop.

I am comsidering putting a 140amp alternator. Using a 8000rms amplifier. Could it be that the box is incorrect? Any ideas when it comes to charging the optima battery?

You don't have enough electrical to support 8,000 watts. A single 140 amp alternator is not going to cut it either. If you want to get this most out of this setup and remain in the class you are in, you are going to need the biggest alternator you can find and replace that Optima with the biggest and best battery you can find. If the rules allow it, I would do some fabrication (if necessary) and use a group 31 battery like XS Power's D3100. You're going to need all the help you can get to even attempt to satisfy the demands of an amplifier making 8,000 watts rms on a 12 volt system with a single battery and alternator.

@ Ohjay,

What is a group 31 battery?

If i use a smaller amplifier and same battery can i achieve the same figure or even higher if i tuned the box to a higher frequency?

Higher frequency = Less power draw. I stand to be corrected.

i am still trying to learn as much as i can.

Group 31 just refers to the size of the battery. It is usually the largest battery that most people can fit in an under hood application. Since the battery case is much larger than most, the factory producing them can pack more inside, giving you more available power. Tuning to a higher frequency will generally (but not always) increase your spl score, so in theory you could possibly raise the tuning of your enclosure and use less power to achieve a similar score. Nobody can really tell you if you will be able to get louder or even achieve the same score as before after dropping amplifier power. I'm guessing your "cutoff" is simply your amp going into protection mode due to low voltage? How long does it take for this to happen during your Termlab testing? Does it happen within a few seconds of a heavy bass note?

Yes it generally cuts off and goes into protection within a fews seconds on heavy bass. Generally as the car starts to peak on the meter and then just clips. I haven't to date seen it hit full. Plz tell me how to incresase the frequency of the box.

Yes it generally cuts off and goes into protection within a fews seconds on heavy bass. Generally as the car starts to peak on the meter and then just clips. I haven't to date seen it hit full. Plz tell me how to incresase the frequency of the box.

Increasing the tuning of the box isn't really going to help you. You need to get a bigger alternator.

Think of it this way. Your alternator is a water pump. The battery is a jug. The amp is little thirsty children...

If the jug keeps running empty and the children get upset, you can get a bigger jug that'll hold more water, but what you really need is a stronger water pump to keep the jug full.

So get a new alternator! That's the only thing that will help you.