Why would a second battery increase this effect? If anything, it should reduce it.

Not saying a big increase, but you are still using power from the battery if you can't supply enough with the alternator. Still have to charge the battery while everything is in play.

Most people don't play constant bass tones in their car, the alternator has time to replenish that extra battery. An extra battery adds to the peak amps that the system can use...much more than a simple alternator upgrade can do...unless you're running ten of em at one time....not uncommon in SPL competition vehicles running constant bass tones...but you'll also see a stack of batteries in back too.


TOC Admin
Brando

Another instigation?


We shall see.


For two, or more, it will depend on their states of charge. the lower one will get a higher percentage until they are equal, or fully charged.

In any event, they will be charged, on an as needed basis, using any current available after powering all active electrical circuits.

Your "strain", is still not possible.


In that case, as 87 Delta said, anything the alternator cannot supply is taken from the battery. If the battery goes flat, it will be a different topic.


No strain = no increase. A reduction is very likely since the reserve capacity has been significantly increased.

Your confusion came from the "blown fuses" 88delta88 alluded to. They were not caused by his extra battery, and therefore your original comment was baseless.

Upside is, we have all learned from the discussion it caused.

Norm

The blown fuses were instigated by myself turning the volume up too high, but no instigatory undertones implied.

What circuits blew fuses? You know, the fuses that were not instigatees.

Norm

I have 2x30A fuses in paralell 8" from my main battery on the power wire running to the rear battery. Every so often (happened to me 3 times in 3 years), when I play the stereo extrordinarily loud, the fuse will break.

I will not notice, since the stereo still runs on the charge from the rear battery, until the volts start dropping in the trunk on my voltgauge, and I then know my fuse has quit again.

I thought about upping the fuse value, or adding a third 30A fuse in line, but I think 60A does my needs for the most part. Better safe than sorry! A cicuit breaker might be an idea for a boring day.

30 amp seems a little bit low. You can easily get away with a 50 or 60. I used a 50 amp 12V circuit breaker (was free) for when I had my set-up going.

Just a thought, but it seems like we've moved pretty far away from the big three question we started with.... maybe we could move the most recent posts to a "one battery vs. two or more batteries" topic? This is an interesting discussion, but it seems misplaced. Then again, I haven't been here very long and I'm not a moderator

You should be fine with more. I got a 150a fuse for the main power cable which goes to a distribution block, and the block has 60a fuses for each line. Plenty of protection, but not overkill, no such thing.
So far I only blew one of the 60a fuses.

I agree with moving blatantly off topic (hijacks) discussions to a new thread. Problem is, trying to define the realistic borders of a topic. If you limit it too much, the interest is lost followed by the thread.

In this case, the subject has not changed, but is covering more of the original subject than might have been expected. Basically, the wires go to ground, the alternator, and a battery, If a fuse or an auxiliary battery might improve it, it should be part of the same topic.

The problem I see, is when a new guy does a site search before posting a question. The same latitude that makes for our productive discussions, creates problems when he (or I) do a subject search.


As far as I noticed, batteries were peripheral to Basic three, and were dealt with as such.


Is it that you do not normally witness the freedom to discuss, any outside factors and their cause and effect as they relate to a subject?

The subject is a tricky one, and I think such decisions should be left to the mods, since the make the big bucks.

Now that I think about this post, it should be in its own thread.

Norm

Doesn't he already have 60 amps?


Are you saying, a fuse cannot be too big for the circuit it is protecting?

Norm

Good call, Norm. I thought about some of that after I posted. Would it make sense or is it possible to make the two battery disscussion something that would be easier to find for those looking for information on that subject? Sorry, done with that tangent... back to the matter at hand...

88Delta88, I have a similar setup to Gravereaper's, except with slightly smaller fuses. I have a 100 amp fuse near the battery and twin 30 amp fuses on my distribution block, one for each amp and have never had any problems. I've never had a fuse blow. However, if blowing a fuse every once in a while doesn't bother you, don't worry about it. At least you know you are protected!

-Carl

Although I am running 2 - 30A fuses, I am not limited to 30A. In parallel, the two 30A fuses actually allow 60A of current to flow through them.



I dont beleive larger fuses allow less resistance on the circuit (can someone verify this?) so, I only fuse for the maximum amount of power I am drawing at any one time. I dont mind changing a couple 30A's once in a blue moon.

^ Although it'd probably be easier and cheaper to replace one fuse...
I'd have to disagree, I believe the larger fuse would be less resistance compared to the two smaller fuses....it is a weak point in your system. I can't say for sure, but just by comparing my ANL 100amp fuse to an AGU 60amp....I'll have to measure the resistance some time when I get a chance.

I have to add that in general...the fuse is a weakpoint...it's what it's meant to do.... Probably wouldn't make a considerable difference in your systems performance to upgrade to one large fuse...other than the fact that it would be cheaper and easier to replace as said above...

And it certainly is possible to use too large of a fuse, the fuse size depends on what the wire can safely handle without causing a fire (not cool), not how much the amplifier peak current draw is--which is what decides what wire size/gauge you use in the first place. You also want to fuse the smaller wires if you're stepping down with a distribution block, which most dist. blocks have built in.

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Brando