the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

batteries or caps?


Post ReplyPost New Topic
< Prev Topic Next Topic >
jaybizz 
Member - Posts: 30
Member spacespace
Joined: February 02, 2008
Location: New York, United States
Posted: March 25, 2008 at 6:24 AM / IP Logged  
would u say it is better to run a second battery in the trunk specifically the new kenetic battery with a 200 amp relay/isolator under the hood or would u say to use a couple of caps in the trunk, or both. many people have a lot of different ideas how a cap works. what and how does a cap really work. to my knowledge i was lead to believe that it makes sure the amp has full voltage at all times. obviously the first thing people always used to say was it helped dimming of the lights which to me is not true. only an alternator upgrade seems to take care of that problem.
alarm king
haemphyst 
Platinum - Posts: 5,053
Platinum spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: January 19, 2003
Location: Michigan, Bouvet Island
Posted: March 25, 2008 at 7:13 AM / IP Logged  
Big 3, first. Then, high output alternator, ONLY. Then a second battery (identical to the first one, which means you are buying two). In that order, and you'll notice I made no mention of caps or isolators.
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
klctexas 
Copper - Posts: 111
Copper spacespace
Joined: March 10, 2008
Location: Texas, United States
Posted: March 25, 2008 at 8:23 AM / IP Logged  
Doesn't a second battery need to be isolated from the main starting battery? Otherwise they'll kill each other off? That's what i've always seen.
Soldier: This is the worst part. The calm before the battle.
Fry: And then the battle is not so bad?
Soldier: Oh, right. I forgot about the battle.
jvillefinest 
Copper - Posts: 255
Copper spacespace
Joined: December 29, 2003
Location: Florida, United States
Posted: March 25, 2008 at 9:42 AM / IP Logged  
It doesnt "need" to be isolated, but i alway suggested it to all my customers and have the secondaries isolated. I just like having the ability to play the system and not have to have the truck running or worry about the truck not starting. But if you do isolate them be sure to fuse before and after the isolator.
As far as the alternator, i am still running the stock alt powering the running batt and 2 secondaries for almost two years now. I wouldnt suggest this because YES it is going to kill the alt but at that point i will upgrade. But for most vehicles this isnt going to work unless its a truck or something with a larger alt.
2007 Acura TSX
SQ setup in the works
skee-weezy 
Copper - Posts: 177
Copper spacespace
Joined: March 08, 2008
Location: Michigan, United States
Posted: March 25, 2008 at 9:56 AM / IP Logged  

i have to agree with haemphyst..... caps are mostly hype... not worth the price of admission most times..... do the big three and u will be in better position to bump hard and do it for a long time... and your equipment will thank u for it.........

********smacks himself***********

don't mind me... i'm just hung over........

there can be only one.......
KPierson 
Platinum - Posts: 3,527
Platinum spaceThis member consistently provides reliable informationspace
Joined: April 14, 2005
Location: Ohio, United States
Posted: March 25, 2008 at 12:57 PM / IP Logged  

If your alternator is big enough to handle both batteries no isolator is needed.  The batteries won't kill each other because once they equalize there will be no difference in potential so no electrons will flow between them.

The problem most people have is they arn't willing to spend the money for a bigger alternator, so they throw a 2nd battery on the OEM sized alternator, causing it to strain. 

Kevin Pierson
sedate 
Silver - Posts: 1,173
Silver spacespace
Joined: July 03, 2004
Location: Colorado, United States
Posted: March 25, 2008 at 5:51 PM / IP Logged  

KP wrote:
The batteries won't kill each other because once they equalize there will be no difference in potential so no electrons will flow between them.

I'm confused.

Doesn't "equalizing" mean that the battery with the lower ESR drain off the other one - and - uhh - kill it?

jville wrote:
i am still running the stock alt powering the running batt and 2 secondaries for almost two years now. I wouldnt suggest this because YES it is going to kill the alt but at that point i will upgrade.

Are you kdding? Two years?  If this was going to kill the alt it would have done so already.  Hooking two (or three!) charged batteries up to an OEM alt doesn't strain it any more than one does - this depends on amperage demanded of the batteries - not just having two hooked up.

I want you to know dude - I've been hammering away at this point - much to my popular deteriment - on this board for years.  Your sig confirms it, HO alts are totally worthless - what matters is current at 12.5v, everything else is a red herring

"I'm finished!" - Daniel Plainview
KPierson 
Platinum - Posts: 3,527
Platinum spaceThis member consistently provides reliable informationspace
Joined: April 14, 2005
Location: Ohio, United States
Posted: March 25, 2008 at 7:07 PM / IP Logged  
sedate wrote:

KP wrote:
The batteries won't kill each other because once they equalize there will be no difference in potential so no electrons will flow between them.

I'm confused.

Doesn't "equalizing" mean that the battery with the lower ESR drain off the other one - and - uhh - kill it?

No, it means that if battery A is 13.654 volts and battery B is 13.652 volts (and they are identical batteries) then battery A will charge battery B to around 13.654 volts.  At that point, both power supplies are equal, and since there is no difference in potential no current will flow.  It's the same concept of installing a cap (a power storage device).  Once the two power storage devices stablize then no current flows.

Kevin Pierson
KPierson 
Platinum - Posts: 3,527
Platinum spaceThis member consistently provides reliable informationspace
Joined: April 14, 2005
Location: Ohio, United States
Posted: March 25, 2008 at 7:13 PM / IP Logged  
sedate wrote:

jville wrote:
i am still running the stock alt powering the running batt and 2 secondaries for almost two years now. I wouldnt suggest this because YES it is going to kill the alt but at that point i will upgrade.

Are you kdding? Two years?  If this was going to kill the alt it would have done so already.  Hooking two (or three!) charged batteries up to an OEM alt doesn't strain it any more than one does - this depends on amperage demanded of the batteries - not just having two hooked up.

I want you to know dude - I've been hammering away at this point - much to my popular deteriment - on this board for years.  Your sig confirms it, HO alts are totally worthless - what matters is current at 12.5v, everything else is a red herring

This is an exception, and not a rule.  All cars are different, and most alternators are different.  If you put three charged batteries in the vehicle I would agree that at first there would be minimal load added.  But, as you draw current away from the batteries at a rate faster then the alternator can charge you'll stress the alternator.  Heaven forbid you leave the lights on for 30 mintues with the car off (or listen to the radio with the car off).

Now, your alternator has 3x the load to charge back up, which will make it work 3x harder.  It's simple math if you have a 100 amp alternator and a 150A load eventually you're going to have problems.

Kevin Pierson
sedate 
Silver - Posts: 1,173
Silver spacespace
Joined: July 03, 2004
Location: Colorado, United States
Posted: March 25, 2008 at 7:30 PM / IP Logged  

KP wrote:
No, it means that if battery A is 13.654 volts and battery B is 13.652 volts (and they are identical batteries) then battery A will charge battery B to around 13.654 volts.  At that point, both power supplies are equal, and since there is no difference in potential no current will flow.  It's the same concept of installing a cap (a power storage device).  Once the two power storage devices stablize then no current flows.

Huh.  Okay - I'm not trying to argue, just looking for a more complete explanation (and you do have that "i" and that third star) - but how does the ESR thing play into this?  Is this too a red herring?

KP wrote:
battery B is 13.652 volts (and they are identical batteries)

I guess this is the biggest issue I have with your explanation - you take careful pains to paranthetically state "(and they are identical batteries)" - is that you don't explain why they 'equalize' with identical batteries, but you avoid what happens when diffferent batteries are used or how this impacts your logic here.  I feel this is a wholly incomplete explanation that, as stated, is full of holes.

"I'm finished!" - Daniel Plainview
Page of 2

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

  •  
Search the12volt.com
Follow the12volt.com Follow the12volt.com on Facebook
Tuesday, January 31, 2023 • Copyright © 1999-2023 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer