Need more juice for stereo???

Since I was given advice (by J_I_H ) to repost my quest for help instead of posting on a "tired" thread here it is again.....

I don’t know where to start. Not an electrical guy. With our new 94 SN, it has a stock Alternator, I believe the stock stereo amp, a new CD player head unit and 4 stock speakers. I believe it(alternator or battery) are not putting out enough power. The ignition beaker needs to be on for anything to work first, if the blower or auto bilge is on then the stereo does not have enough power to turn on. If these things are turned off then it will work. Also while motor is running all things will work. Push the horn and stereo goes off, or the bilge comes on, stereo goes off.

Please let me know what I can do to eliminate this. I need help. I'm NOT trying to have a 500 watt stereo blaring while we are running but just trying to enjoy a few tunes while out on the lake…..I have 3 or 4 teenagers in the boat all the time so the stereo is a necessity.
Thanks!

The best way to have the amperage needed is simple,however the manufacture is too cheap or doesn't have a clue.
Coming from a truck, bus ,environment in order to have the power needed rather than to put put on a ridiculous alternator that in time will melt your battery..

You put two 6 volt batteries in series you will have 12 volts and double the amperage ex. 2 -6 volt 500 amp would give you 1000 amp and 12 volts. This will not over work your alternator and melt the batteries. You will have all the power needed end of problem.

Tim D, he should put an in-line fuse in the line he runs from the amp to the battery right? What size wire should he run? #10?

Be sure to get marine grade wire. Do not use wire you get at the auto parts store.

the guage of wire will depend upon the amp, I use #8 on mine. Most newer amps have a fuse built into them so there is no need for a inline fuse.

The voltage regulator could be going out in the alternator, you might want to have it tested.

not yet it's sitting on a craddle in the barn right now.

Two 6 volt batteries in parallel will give you 6 volts and 500 amps. Two 6 volt batteries in series will give you 12 volts and 1000 amps. End of quote.

I'll weigh in (don't know why...guess just bored today). I agree with GottaSki. Batteries wired in series will increase voltage, but capacity remains the same.

When the batteries are wired in parallel, you are doubling the capacity but the voltage remains the same. You cannot do both... it's an either or kind of thing.

79...

Not sure where you are coming from on this, but I guess I can clarify my position and say that if you have amultiple battery bank (more than two) then you can indeed increase voltage AND capacity by doing a combination of wiring the batteries (or cells) in series and in parallel. Not on the same cell/battery, but some in series and some in parallel.

Just to make sure I am not all wet on this, I did some looking on the internet (and you know everything you read is accurate) to support my argument. Tell me again why I chimed in?

The batteries where all in series and it was not a compination of paralell and series, they where even stacked on top of each other and ever single one had their own heating element as well as several sensors within the craddle that they where mounted in.

I just don't know why anyone would want to series 6 volt batteries to increase capacity. Why not parallel two 12 volt batteries. This is what is normally done. In fact, with two parallel 12 volt batteries a disconnect switch can be added to disconnect your engine starting battery from your stereo when setting at the dock so you don't discharge your "main" battery. By doing this you can use a smaller 12 volt "motorcycle" type battery for your second "stereo power" battery. Switch in the smaller battery while running to recharge it.

However, I see no gain of having two 500 amp/hr 6 volt batteries over one 1000 amp/hr 12 volt battery.

J_I_H:

Argh! Are we speaking on the same subject or using the same terms? Let's try it this way: Take two identical 12 volt batteries. Now, put a theoretical load of maximum voltage on one of the batteries so that it will be exhausted in exactly one hour. Now wire the two batteries in series: maximum load, at 24 volts, will exhaust the batteries in one hour. Now wire the two batteries in parallel: maximum load, at 12 volts, will exhaust the batteries in two hours.

I agree with: "I see no gain of having two 500 amphr 6 volt...."

PS. Your diagram (parallel) looks good to me.

For what its worth...
The old school method of putting two 6volts in series actually came about because not so many years ago the only decent deep cycle batterys to be found were 6 volt batterys used in golf carts, so if you needed a reliable 12 Volt set up you put them in series. Nowadays you can get 12 volt deep cycles.. and two of them in parallel is a much better solution precisely because if one goes bad your still in business. Conventional wisdom has not necessarily caught up to the technology in some circles...