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Thread: Running two batteries |
    
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 664
Registered: Oct-06
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| Posted on Sunday, May 06, 2007 - 11:40 pm: |
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how could i wire them up...i am thinkin of a kinetik hc1800 up front and a kinetik hc2400 in the trunk. would i need a battery isolator for that? if so could someone draw up a diagram for me to follow. |
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Gold Member Username: Adddisorder
West palm,
Florida
Post Number: 4245
Registered: Jan-06
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| Posted on Monday, May 07, 2007 - 12:48 pm: |
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in parallel you only need an isolator if you want them isolated |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 676
Registered: Oct-06
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| Posted on Monday, May 07, 2007 - 11:46 pm: |
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what would happen if i didnt isolate them?? and what does parellel mean? is that 2 runs of wire (1 + and 1-) from battery to battery? |
Gold Member Username: Adddisorder
West palm,
Florida
Post Number: 4252
Registered: Jan-06
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| Posted on Tuesday, May 08, 2007 - 10:24 am: |
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+ to + and - to - if you isolate them the front will be dedicated as a starter bat and for your cars electronics, and the rear will be only for audio. you dont need to isolate them in your case but you can if you want that option |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 678
Registered: Oct-06
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| Posted on Tuesday, May 08, 2007 - 11:29 pm: |
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why wouldnt i have to isolate them?? would it hurt my car if i dont?? |
Silver Member Username: Waterboy2289
Georgia,
DiRtY SoUtH ...
2 18 SX w/ ...
Post Number: 374
Registered: Jan-06
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| Posted on Wednesday, May 09, 2007 - 08:59 am: |
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^^^Before I answer that, you need to know that there are two different ways to isolate your rear batteries: by using an isolater or by using a relay(solenoid).
An isolater is installed between your front and rear batteris and will allow you to play your system with the car off and only drain your rear battery. When the car is on, it only allows current to flow to the rear batt after the fron batt is fully charged. It will not allow you to drain the fron batt.
The relay is installed between the front batt and rear batt just like the isolater. But all the relay is is a switch. It separates the front and rear batts when the car is off. When the car's on the batts are connected as if there is nothing between them. The relay is used to separate different batteries so as their different internal voltages will not drain each other when the car is off.
.......I'll post more later. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 681
Registered: Oct-06
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| Posted on Wednesday, May 09, 2007 - 08:18 pm: |
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so what one is better? |
Gold Member Username: Nd4spd18
Southeast PA
Post Number: 2240
Registered: Jul-06
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| Posted on Wednesday, May 09, 2007 - 08:56 pm: |
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The isolator. Those relays do not constantly isolate the system, when they are enabled the two batteries are connected.
With the isolator the two electrical systems are truly separate. |
Silver Member Username: Waterboy2289
Georgia,
DiRtY SoUtH ...
2 18 SX w/ ...
Post Number: 383
Registered: Jan-06
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| Posted on Wednesday, May 09, 2007 - 09:15 pm: |
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Go with the relay......
"Those relays do not constantly isolate the system, when they are enabled the two batteries are connected."
I'm well aware of this, and I noted that in my brief description of relays.
"With the isolator the two electrical systems are truly separate."
Unless he is planning on playing his system with the car off, having two 'truly separate' electrical systems wouldn't be of any real benefit. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 684
Registered: Oct-06
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| Posted on Wednesday, May 09, 2007 - 11:34 pm: |
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so just want to be able to drive and not worry about having my batteries drained...what one should i use? and what exactly is a relay? |
Gold Member Username: Nd4spd18
Southeast PA
Post Number: 2275
Registered: Jul-06
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| Posted on Thursday, May 10, 2007 - 12:28 am: |
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The isolator...... I'm copying my posts from other threads here:
An isolated battery dedicated to the audio system is the best way to set up an electrical system, short of installing two alternators (often not an option).
A real battery isolator (diode based) is the way to go. It will allow current to flow from alt to battery 1, and alt to battery 2, but current cannot flow between the two batteries. Diodes have resistance though, and resistance causes voltage loss, usually about 3/4 volt with these isolators. That's not enough to cause any problems though, the batteries will still charge ok.
When using a solenoid/relay, it is installed in-line between the two batteries. The current can always flow from the alt to the front battery. It can flow between the two batteries when the relay is activated. This is not a good setup for a few reasons, one is that a solenoid/relay is not as reliable as a diode based isolator. Other problems (that I don't really want to explain in detail) can be caused by the fact that current flows between the batteries when the relay is activated, depending on the method used to activate the relay.
A battery isolator (diode based, not a relay), will allow you to run two batteries and each will not be able to "see" the other, so current is unable to flow between them. Current can flow from alternator to battery 1 and from alt to battery 2, but not back and forth between the batteries. With this type of system, the audio system could completely drain the back battery, and the front battery would remain full (the type of front battery and anything else connected to the cars electrical has no effect on the audio system, and vice versa) |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 690
Registered: Oct-06
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| Posted on Thursday, May 10, 2007 - 12:34 am: |
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ok thanks |
Silver Member Username: Waterboy2289
Georgia,
DiRtY SoUtH ...
2 18 SX w/ ...
Post Number: 385
Registered: Jan-06
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| Posted on Thursday, May 10, 2007 - 08:07 am: |
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There is no need to have the batteries separated except when the car is off. You won't drain your batteries while the car is on. If your amp(s) were pulling more current then your electrical system could put out, your amp(s) would shut off before your batteries drained. Not only is a relay cheap, but it can also take much larger current draws through it than a isolator.
MS, what is wrong with having current constantly flowing between all the batteries? |
Gold Member Username: Nd4spd18
Southeast PA
Post Number: 2282
Registered: Jul-06
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| Posted on Thursday, May 10, 2007 - 02:21 pm: |
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Nothing. I explained the potential problem with relays in my last post here:
http://forum.ecoustics.com/bbs/messages/4/353608.html |
Silver Member Username: Waterboy2289
Georgia,
DiRtY SoUtH ...
2 18 SX w/ ...
Post Number: 399
Registered: Jan-06
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| Posted on Thursday, May 10, 2007 - 09:56 pm: |
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All right then. If he is not playing the system with the car off(or the ignition switched on and the car off), then an isolator would be of no use to him. A relay would take care of his battery separating needs.
"The relay is inherently flawed in it's design."
A relay is not flawed in its design just because it does not do exactly what an isolator does. A relay and an isolator are two different pieces of equipment, each designed with specific applications in mind. One is not 'better' than the other; however, depending on the application, one will be the correct piece of equipment for the task. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 697
Registered: Oct-06
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| Posted on Thursday, May 10, 2007 - 11:20 pm: |
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so with the car on and running i should use a relay?? |
Silver Member Username: Waterboy2289
Georgia,
DiRtY SoUtH ...
2 18 SX w/ ...
Post Number: 402
Registered: Jan-06
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| Posted on Thursday, May 10, 2007 - 11:38 pm: |
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Before I can answer that, I need to know if you will be playing the system with the car off(or the ignition switched on and the car off).
If you only use the system while the car is running, then a relay is what you want. The reasons: lower voltage drop across the relay(as compared to the isolator), inexpensive, and more current flow possibilities. What I mean by current flow possiblities is that you can either use one Stinger 200amp relay or wire two of them together for 500amps of current. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 765
Registered: Oct-06
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| Posted on Tuesday, May 15, 2007 - 01:53 pm: |
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yea car will be on deffenitly...where can i get a relay? |
Bronze Member Username: Kpa2727
Post Number: 67
Registered: May-07
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| Posted on Tuesday, May 15, 2007 - 08:22 pm: |
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http://www.knukonceptz.com/
from what i hear, thier the best for any type of wiring needs try them see if they have what your looking for. |
Silver Member Username: Waterboy2289
Georgia,
DiRtY SoUtH ...
2 18 SX w/ ...
Post Number: 426
Registered: Jan-06
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| Posted on Wednesday, May 16, 2007 - 01:27 am: |
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You can get one here:
http://cgi.ebay.com/Stinger-200-Amp-Battery-Relay-Isolator-5-50-Ship-SR200_W0QQi temZ170109381041QQihZ007QQcategoryZ50552QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
That's a good seller. I've bought several things from him including my relay. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 785
Registered: Oct-06
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| Posted on Wednesday, May 30, 2007 - 11:50 am: |
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so what if i didnt want a relay and i just connected both batteries together and then hooked up my amp to the back battery? what would be a difference if i did that without a relay?? keep in mind that the car is on.i need to know if it would be alright to just connect + and + and ground the batteries seperatly. |
Gold Member Username: Nd4spd18
Southeast PA
Post Number: 2802
Registered: Jul-06
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| Posted on Wednesday, May 30, 2007 - 05:41 pm: |
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You can do that only if the batteries are the same |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 789
Registered: Oct-06
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| Posted on Wednesday, May 30, 2007 - 08:19 pm: |
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so i was thinking a kinetik hc1800 up front and a hc2400 in the back. does that count as the same batteries? |
Gold Member Username: Th3pwn3r
Post Number:...
Post Number: 2858
Registered: Jul-06
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| Posted on Thursday, May 31, 2007 - 11:04 am: |
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You would be fine doing that Phillp.Just make sure that your voltage doesn't drop too low when you're playing with the car off or you won't be able to start your vehicle and you could also damage things such as the amp and sub by dropping too low in voltage as we have mentioned to you before. |
Gold Member Username: Carguy
Post Number: 6256
Registered: Nov-04
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| Posted on Thursday, May 31, 2007 - 12:42 pm: |
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If you listen with car off, then go with isolators.
Relays are great under the right condition. The problem is, most of the time, the 2nd battery is either half empty or empty. In a relay system, the aux battery will rob power from the starter till both are fully charged. Not an ideal thing to do during winter.
If you read up on relay vs isolator, then you'll be able to see the full picture. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 790
Registered: Oct-06
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| Posted on Thursday, May 31, 2007 - 12:56 pm: |
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do you think it my voltage will drop alot with the car on?? |
Gold Member Username: Carguy
Post Number: 6260
Registered: Nov-04
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| Posted on Thursday, May 31, 2007 - 03:00 pm: |
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Your voltage drop will depend on how discharged your 2nd battery is.
Honestly, keep it simple and install an isolator. That way, you can run it with engine run or off and not have to worry.
Some people will make the voltage drop due to isolator a big deal. However, if you have a external charger and top it off once a month, you'll be fine. |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 791
Registered: Oct-06
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| Posted on Thursday, May 31, 2007 - 11:32 pm: |
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what do you mean by a external charger and to top it off?? |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 793
Registered: Oct-06
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| Posted on Friday, June 01, 2007 - 12:04 am: |
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bump |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 795
Registered: Oct-06
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| Posted on Friday, June 01, 2007 - 01:34 pm: |
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what do you mean by an external charger and to top it off?? |
Gold Member Username: Carguy
Post Number: 6271
Registered: Nov-04
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| Posted on Monday, June 04, 2007 - 09:45 am: |
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External charger as in automatic car battery charger. You can get one for $50. It'll ensure that the starter battery is fully charged.
If you do it once a month, it should take less than 3 hours to "top it off." |
Silver Member Username: Holt_champ
Htown,
MI
Post Number: 801
Registered: Oct-06
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| Posted on Wednesday, June 06, 2007 - 01:39 pm: |
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one more thing...my friend said that there is a battery called interstate or sometihng like that. i guess they are used in for racing. would those be good batteries or would kinetik be better? |
Bronze Member Username: Basebalz13
Moneta,
Va
Usa
Post Number: 22
Registered: Aug-07
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| Posted on Saturday, September 08, 2007 - 12:06 am: |
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kinetik all the way |
New member Username: Zxhoon
Post Number: 6
Registered: Sep-07
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| Posted on Sunday, September 23, 2007 - 03:17 am: |
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you should use an isolator, if your rear battery is drained a lot and you turn on the relay to connect it to charge the inrush current could weld the contacts closed making the relay useless...
all manufacturers state you should only connect 2 identical batteries in parallel, they need to be the same size (capactiy), same age (new), etc.
as with any wiring from a battery, make sure you use a fuse that will protect the wiring otherwise a short could cause the battery to explode or your car to catch fire... keep it safe ;) |
