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View Full Version : Here's a What If Statement...about Batteries



mushroom_toy
07-22-2007, 06:58 PM
Not sure where to put this but I'm gonna post it in general. I was thinking since it takes gas to basically run an engine and charge your battery, what if I was to run two batteries in parallel. I could prolong the voltage output. In this effect would I be saving gas or getting better gas mileage or no?

russiankid
07-22-2007, 07:01 PM
I don't see how you would save gas because the pump would still put out the same amount of fuel. And the stock alt. may not handle it, plus i doubt the alt puts a BIG load on the engine anyways.

A18A
07-22-2007, 07:05 PM
the weight of the extra battery would probably take away gas mileage lol

mushroom_toy
07-22-2007, 07:05 PM
I don't see how you would save gas because the pump would still put out the same amount of fuel. And the stock alt. may not handle it, plus i doubt the alt puts a BIG load on the engine anyways.

Stock alternator should handle it. It will be same voltage. If i ran it in series it would be 24 volts, but I would be running them in parallell, so still 12 volts. this would give more power storage.

frantik
07-22-2007, 07:06 PM
In this effect would I be saving gas or getting better gas mileage or no?

no


the weight of the extra battery would probably take away gas mileage lol

that


:)

mushroom_toy
07-22-2007, 07:08 PM
no



that


:)

I have removed a lot of things so it owuld equal out...on the weight anyway.

Pico
07-22-2007, 07:19 PM
the only advantage would be you would have enough power to run extra accessories, there would be no gas saving advantage unless your car was going to be powered by the batteries (a hybrid 3G)

mushroom_toy
07-22-2007, 07:21 PM
the only advantage would be you would have enough power to run extra accessories, there would be no gas saving advantage unless your car was going to be powered by the batteries (a hybrid 3G)

Got ya, I didn't know how much pull the alternator made on the engine. I believe everyone but if i can find a spare battery I might try it anyway. I won't be running a lot of accesories anytime soon, but who knows.

Legend_master
07-22-2007, 08:08 PM
Got ya, I didn't know how much pull the alternator made on the engine. I believe everyone but if i can find a spare battery I might try it anyway. I won't be running a lot of accesories anytime soon, but who knows.


The only way to take the load of the alternator off would be to remove it completely. The alternator is driven by a belt on the motor, not controlled variably by the battery.

A18A
07-22-2007, 08:13 PM
which would mean no water pump, unless you replace the alternator with a adjustable pulley, which would probably take as much load as a alternator =P

2ndGenGuy
07-22-2007, 08:44 PM
The only way to take the load of the alternator off would be to remove it completely. The alternator is driven by a belt on the motor, not controlled variably by the battery.

True, but I can see where he's getting at. The more load the alternator gets, the more resistance it puts on the belt, and therefore the engine.

The thing is, for every hit to the battery that isn't immediately drawn from the alternator, you alternator will have to work just as hard to charge it up again. Having two batteries isn't going to magically make electricity come from nowhere. Your car will still use the same amount of electricity, and it will still have to come out of your alternator. It might just save the peak loads from hitting your alternator so hard.

Legend_master
07-22-2007, 09:58 PM
True, but I can see where he's getting at. The more load the alternator gets, the more resistance it puts on the belt, and therefore the engine.
The thing is, for every hit to the battery that isn't immediately drawn from the alternator, you alternator will have to work just as hard to charge it up again. Having two batteries isn't going to magically make electricity come from nowhere. Your car will still use the same amount of electricity, and it will still have to come out of your alternator. It might just save the peak loads from hitting your alternator so hard.


The alternator only turns as fast as the engine RPMs. That would mean that the alternator is always charging, but only at the rate that you drive the engine.

88accordSF
07-22-2007, 10:08 PM
Having two batteries isn't going to magically make electricity come from nowhere.

no alternator = not going very far

no battery = going nowhere at all

parallel batteries is for heavy electronics use while the car is off

high amperage alternator supports heavy electronics while running

all you need is one Optima battery. check out how they are made.


The alternator only turns as fast as the engine RPMs. That would mean that the alternator is always charging, but only at the rate that you drive the engine.

amperage vs. rpms charts are usually curved lines. usually after about 2-3k rpms you're making close to full amperage, and the additional amperage to max rpm from 3k is only a bit more (usually, unless honda deployed a completely different style of magnet)

mushroom_toy
07-22-2007, 10:14 PM
This is all interesing.

MessyHonda
07-23-2007, 09:11 AM
yeah the alternator makes most of its amperage at middle RPMs....i think the voltage regulator helps it. my lights get brighter when i rev my car at a stop light. kinda annoying.

lostforawhile
07-23-2007, 09:30 AM
it wouldn't save you a bit of gas,the car electrical load runs off the alternator when the engine is running,not the battery. two batteries would add weight,and more load on the alternator to keep them charged. the only time the battery factors into the electrical system,while the car is running,is if you exceed the output of the alternator. and the alternator by it's design,produces full current at low rpm. this was the reason it was designed in the first place, the old generators wouldn't charge the battery at low rpm. if you wanted to run two batterys,you would need a multiple battery controller. this ensures that your main battery is always charged,and the secondary battery is only charged when the main is full.