AznRukkus

whats the Best battery or way to watch a movie/shows or listen to radio for 2 hours? 4th 93 gen prelude vtec.... im planning on getting a d3 and whatever else thats good... would i need to buy a bigger better battery? i dont have exp.. so i dont want to mod heavily.... is there a battery lightwhere when u get low enuff it tells u/? or saves enuff to start my car? or would i have to get a cig lighter booster plug thingie?

ExodusFX

I don't watch movies in my car with it shut off, so I can't tell you about battery life for different batteries. There is a product called the "Battery Brain" that is an electronic shut off for the battery. You can find it online. It automatically cuts off the positive battery terminal once the voltage drops too much. One side effect of that device is that if it cuts the power, you'll lose memory of your clock and radio. You could always run multiple batteries, if you feel like wiring them up and finding a spot to mount the other one(s). (Wire them in parallel, not series!)

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aznmienxsir

If you want to watch movie for a long time without the engine on, you need to get a deep cycle battery so you won't damage the battery if you drain it all the way. On a standard battery if you drain it all the way too many times, you can kill the battery where it can no longer be used.

With a deep cycle you can drain it as many times as you want and it won't hurt the battery. You may not be able to start the car if you drain it too far, but you can always jump it. Also since it is a deep cycle, it will drain slower then a normal battery so you can use it without the engine for a longer period of time.

The most popular deep cycle battery is the "Yellow Top" by Optima.
Optima Products - YellowTop

It is pretty expensive but worth the money. If you want a cheaper way of doing it just go to your wal-mart or where ever that sells battery and buy a deep cycle "Marine or RV" battery. Usually they have a blue sticker, tag or something blue on it.

I would not run multiple batteries. It requires more then just connecting it up in parallel. You need other component like an isolator. Also you may need to upgrade your alternator to support the 2nd battery because you will be charging up 2 batteries instead of one. Also if you do use 2 batteries, you will want to buy a deep cycle for the 2nd battery instead of a normal battery.

AznRukkus

thx that was nice...

ExodusFX

Okay, don't spread incorrect information.

You don't need an isolator to run multiple batteries. You just need to have both batteries fused at their positive posts. Running two batteries without an isolator is just like using one big battery. You don't need to change any of the car's wiring.

You can use an isolator if you would like; that would separate the ignition and starter's power source from the radio/amps/etc. Going that route, you would have to rewire the car so that everything you want separate from the starting battery is now only wired to the second battery. (more of a pain to do)

Having a deep cycle battery has only one benefit; being able to recharge it and not have it lose much capacity (unlike a normal battery) after a full discharge. It will not give you any longer play time for your radio. Deep cycle batteries do not "drain slower."

Bottom line, the only thing that will give you more play time is increasing the size of the power source. You can do this by using multiple batteries or by buying a single battery with a higher capacity. Deep Cycle vs Standard is irrelevant.

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AznRukkus

but yellowtop optimas are still the best? why can there be a light that tells u ur car is running low on batteries... = (

aznmienxsir

From my standpoint yes because you get a longer use of the battery and you are able to drain without a problem. But ExodusFX disagree with the first part. It has been a while since I was seriously into car audio so I could be wrong on that part. I will look into what I've said and what ExodusFX said about the battery being drained slower. I will get back to you on that later if I find any new info on it to support my theory.

ExodusFX

You could always buy and install a voltage gauge that way you can look and see when the voltage has dropped below an acceptable level.

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ExodusFX

If both batteries are the same voltage (lets say 12.5v), nothing will change how much current is drawn from them, other than switching to different equipment that draws less power. The battery does not control that. It cannot make itself "drain slower."

You can believe me because I do mobile electronics for a living, or you can just look up basic info on electrical circuits.

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