How do I wire/stall a second battery

[basshead7890 128]

I just bought the hifonics brz1700.1d and the Shuriken SK-BT60, do I conected like this and ground the second battery to the chassis. I have a 95 honda accord

[shizzzon 461]

yes, once power line leaves the starting battery and starts heading to back battery, put fuse within 18" of starting battery and within 18" of the back battery and within 18" of the amp.

If your back battery rests higher or lower than your starting battery... your alternator will be in a constant cycle of charge all the time. It won't be at full output but it's not ideal if they rest differently.

In my opinion, if this were the case, i would get a solenoid. I would charge each battery up separately to full charge, then install the solenoid.

This will prevent the alternator from running in a low but constant charge cycle.

I'll give u an example-

let's say starting battery was at 12.7v and back battery was at 12.9v.

When you connect them together, the back battery(because it has higher voltage) will dump partial load into the front battery to "equalize" the load.

Typically, it would lower it to about 12.6v, lower than the lowest battery in the link, or 12.7v but definitely lower than 12.9v, the highest reading in this example.

Now, this is what's goin on- Your front battery is being "charged" by your back battery but ur back battery was charged before you connected it to the front battery....

so now u start the car and the alt comes on....

The alt needs to charge the back battery because it keeps dumping a load into the front battery every time u turn the car off!

Once u turn the car on, the alt is the king of the electrical system so there is no charging confusion when vehicle is on... but because u have an extra battery, every time the car is shut off, the battery drains out a little to keep front battery leveled because they rest differently... so now the alt has a load again next time u start it back up.

this is an example that i've seen and could actually happen to me if i didnt use solenoids.

My front battery rests at 12.8v and my back rests at 13.1v.

When they combine, they all rest at 12.7v.. that's a 0.4v drop.. that's not good.

[basshead7890 128]

yes, once power line leaves the starting battery and starts heading to back battery, put fuse within 18" of starting battery and within 18" of the back battery and within 18" of the amp.

If your back battery rests higher or lower than your starting battery... your alternator will be in a constant cycle of charge all the time. It won't be at full output but it's not ideal if they rest differently.

In my opinion, if this were the case, i would get a solenoid. I would charge each battery up separately to full charge, then install the solenoid.

This will prevent the alternator from running in a low but constant charge cycle.

I'll give u an example-

let's say starting battery was at 12.7v and back battery was at 12.9v.

When you connect them together, the back battery(because it has higher voltage) will dump partial load into the front battery to "equalize" the load.

Typically, it would lower it to about 12.6v, lower than the lowest battery in the link, or 12.7v but definitely lower than 12.9v, the highest reading in this example.

Now, this is what's goin on- Your front battery is being "charged" by your back battery but ur back battery was charged before you connected it to the front battery....

so now u start the car and the alt comes on....

The alt needs to charge the back battery because it keeps dumping a load into the front battery every time u turn the car off!

Once u turn the car on, the alt is the king of the electrical system so there is no charging confusion when vehicle is on... but because u have an extra battery, every time the car is shut off, the battery drains out a little to keep front battery leveled because they rest differently... so now the alt has a load again next time u start it back up.

this is an example that i've seen and could actually happen to me if i didnt use solenoids.

My front battery rests at 12.8v and my back rests at 13.1v.

When they combine, they all rest at 12.7v.. that's a 0.4v drop.. that's not good.

how do i figure out what size isolators i should use, is a 80 amp isolator good? (http://www.sonicelectronix.com/item_16885_Stinger+SGP38.html) i have a 95 honda accord stock alt and battery

[shizzzon 461]

u wouldnt want an isolator, u'd want a solenoid.... BUT... check the voltage levels after u charge them up to see how they rest.

If they rest the same then don't worry about it. If they don't.. then my opinion is a solenoid.

Isolator causes major voltage drop on the output.

[basshead7890 128]

u wouldnt want an isolator, u'd want a solenoid.... BUT... check the voltage levels after u charge them up to see how they rest.

If they rest the same then don't worry about it. If they don't.. then my opinion is a solenoid.

Isolator causes major voltage drop on the output.

man this stuff is confusing poeple/websites are contradicting each other, so an isolator isn't the same as a solenoid? where do i find a solenoid?

BWD Starter Solenoid

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Starter-Solenoid-BWD_18970440-P_N3063C_A|GRP2020A____

or

BWD Continuous Duty Solenoid

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Continuous-Duty-Solenoid-BWD_18970418-P_N3063C_A|GRP2020A____

Edited August 3, 2010 by marq7890

[shizzzon 461]

quit reading them then, hehe.

here is a 200A solenoid-

http://www.oznium.com/relay200

if u think u would be passing more CONTINUOUS current then that, then u would need another.

You would parallel them together for 400A CONTINUOUS.

Gotta make sure because if u try to pull too much current through a solenoid.. u could damage it. They are just a LARGE relay, it could melt...

But i used to run 4,400w of AQ amps off a 250A alt on a single one and never had a problem.

[jcarter1885 995]

You dont have to get a solenoid or isolator if you dont want to, wont harm your system at all. If anything one day upgrade your starting battery to a dry cell as well, a shuriken if you want to have matching batteries. Wire it the way you have it in the picture and do the Big 3 Wiring in 1/0 and you should be set, put fuses where they belong.

If you plan to do a lot of jamming with the car off then yes you will need an isolator/solenoid between your batteries.

[basshead7890 128]

quit reading them then, hehe.

here is a 200A solenoid-

http://www.oznium.com/relay200

if u think u would be passing more CONTINUOUS current then that, then u would need another.

You would parallel them together for 400A CONTINUOUS.

Gotta make sure because if u try to pull too much current through a solenoid.. u could damage it. They are just a LARGE relay, it could melt...

But i used to run 4,400w of AQ amps off a 250A alt on a single one and never had a problem.

so if i install the 200a solenoid with the 2 batteries i should be fine and everything hook up it wont have a huge impact on my stock alternator?

[basshead7890 128]

You dont have to get a solenoid or isolator if you dont want to, wont harm your system at all. If anything one day upgrade your starting battery to a dry cell as well, a shuriken if you want to have matching batteries. Wire it the way you have it in the picture and do the Big 3 Wiring in 1/0 and you should be set, put fuses where they belong.

If you plan to do a lot of jamming with the car off then yes you will need an isolator/solenoid between your batteries.

will the 2 batteries and amp be a strain on my stock alternator? or did i just waste my money on another battery and should have got another alt

Edited August 3, 2010 by marq7890

[jcarter1885 995]

That will depend on your listening habits and how loud you play your system, get a volt meter and keep an eye on your voltage. To help your alternator out get a small battery charger and charge up the secondary battery every now and then.