voltage drop after battery isolator

i have a kinetik 1400 as my main 12v runs to a pac-200(battery isolator) then runs to a second battery(kinetik 1800) which runs to my jl audio 1000/1. now all grounds have been tested and have a resistance of .3 ohms or less. the main battery voltage settles @ 12.77 on main battery the isolator voltage from the main battery reads the same. the voltage @ the isolator for the second battery reads 10.85, the second battery reads 10.85 and also at the amp it reads 10.85. also would like to mention that at the isolator the 12v switched reads 6.8v(not sure y or if thats normal, its the same 12v switched that connects to the amp. i didnt test the 12v switched that goes to the amp tho but i would guess it also reads 6.8v). now this is all in a prius which doesn't have a alternator like a normal car. so i have 0 gauge everwhere from the main battery throughout all mentioned but i have no way that i know of to do the big three. but with that said i also dont think this voltage drop has anythign to do with the big three i think its somthign to do with the 12v switched at the isolator or somehting wrong with the isolator. i have checked all wiring and grounds and everythign is secure and correct except the voltage at the isolator for the second battery an then on.

now my question is if my thinking is correct or not and does anyone else have experience with this? im not by any means experienced with isolators, this is actually my first time working with one. so any and all help is greatly appreciated.

also would like to mention that the prius 12v and second 12v as well as the isolator and amp are all in the hatch of the car. please help!!!!

Switch 12v leads and see if reading changes.......could be burnt contact in pac200......could be bad battery.....could be bad connectors on wire...

is the car running to give these readings?

0.3 Ohms or less on grounds?
So a 10A load causes a 3V drop?
A 100A load is a 30V drop? (IE - your max load will never exceed ~40A??)

The PAC 200 is merely a relay so its "input" voltage should be the same as the first/main battery and its output the same as the second (Kinetik) battery.

Only when the PAC 200 is energised will the 2 voltages be equal.

Are you sure you are energising it?
(I assume you have fuses or breakers at each battery and these are ok?)

ok i will try switching the leads tomoro. im also going to check the 12v switched wire at the amp and at the beginning of the wire(in front of car) to see what voltage it reads. i will also bypass the isolator and parallel the batteries to see what the second batteries voltage is. i think the connectors should be fine they were all brand new from jl audio. i took readings with car running and then with car on acc but i dont remember which readings i am going off of i will re do the readings with on and acc just to document exact readings. i too think its something with the pac200.altho i wont rule out the second battery being bad. i will update tomoro night. thanks

i also forgot to mention that i have inline circuit breakers( 1 within 12" of main battery, 1 in between the isolator and second battery(only about a 18" line, and 1 within 12" of the second battery) all ring terminals are brand new 1/0g. all wiring is jl 0g. xcept for the remote wire of course that is jl remote wire. also have jl battery terminals on the positive terminals for both batteries. stock terminals for neg on both batteries. also should mention i have a stinger 0g to 4g reducer on the amps power and ground terminals(as the amp only accepts 4g).

Make sure that whatever is turning on (energising) the PAC can supply the ~1A it requires, and that the other side is grounded.

Maybe after disconnecting the existing +12V control signal, test with a lead to the primary +12V input.   

BUT BE WARNED!! - 10.85V (Open Circuit) on an AGM battery is VERY flat and can indicate a bad battery (if below 11V etc for a considerable time) and could mean a HUGE inrush current when connected to another battery etc.
BEWARE of sparks!
I'd recommend charging the Kinetik first if it reads below 12V (or even below 12.5V) open circuit and rested.

oooops i didnt mean to submit that... in reply to oldspark.
yes .3ohms or less on all grounds.
"so 10a load causes a 3v drop?" i understand the voltage drop part but idk where u got a 10a load lol sorry im a newb.
same with next question about the 30v and 40a.

yes i have read up on the pac200 and thats why i am seeking advice because it was understanding that there would be know voltage drop with the pac200 and it would isolate my batteries.

yes i have circuit breakers i noted those in previous post

the 10.85v is a reading at the terminals at the isolator which runs to the second battery then the second battery also reads 10.85 then the amp reads the same. im sure u understand what im saying but im very sorry but i dont understand what u r saying. the pac200 is grounded and the ground is good. idk anythign about the 1a it requires. so disconnent te main 12v then run a lead from the main 12v to whta lol im sorry that dont make sense to me. again im new to this an i guess pretty ignorant. both batteries r brand new an yes i know that dont mean that they might not be bad. im not sure of how to charge the second battery i thought the car battery would charge it? havent seen any sparks altho i did flip the circuit breakers so that it dont keep running liek this. so everythign is dicconected right now via circuit breakers.

If the PAC200's ground is 0.3Ohm, that is ok.

But the PAC200 should have 4 terminals = 2 BIG terminals that are to be connected (ie, +12V main battery to secondary battery +12V)...
And the 2 terminals to energise it and connect the 2 batteries - ie, +12V and a ground.

Correct?

The 10A etc referred to grounds for the battery(s) - if they were 0.3 Ohms....   
Then the max current they could supply if i=V/R = ~12.7V/0.3R = ~40A.

yes the pac200 has 4 terminals 2 for the batteries (1 from the main battery,1 to the aux battery) one terminal for ground and one for the 12v switched.

as for the 10a comment lol i get what you were sayign now altho that is way above me :)

i tested the switchedd 12v(on the isolator) and it only reads 6.8v. thats isnt normal is it? i would think it should be 12v, could that be the problem?

Yes - if 6.8V is not enough to energise the PAC 200.
It requires approx 1 Amp at approx 12V (probably above 10V is ok).

thats what i figured. so now i need to find a better 12v lead. right now all i did was tap into the 12v switched wire that goes to the factory amp underneath the passenger seat an ran that back to the hatch then i y adapter it out with one end going to my amp and one end to the isolator.

so after i get a better 12 switched lead then that should energize it enough to send the full 12.7v to my second battery? interesting, how it all works. so becuz it dont have the full 12v(or 10-16v) it does what it can an just so happens it does 10.85v. my sub comes on for a min or less then amp goes int low voltage mode. well now i need to find a new lead an run it this should be fun im guna need more remote wire now.

ogjlbh21 wrote:

---

...it does what it can....

---

Which is nothing.

If the relay's coil/solenoid does not have enough voltage to pull in the contacts, then the two heavy terminals are not inter-connected.

If one is 12.7V and the other 10.85V, then that's because the batteries are 12.7V & 10.85V respectively and they are not interconnected.

i dont understand what that means? are you saying my battery is bad or that i need to fix that 12v switched lead?

i called pac and they told me they dont think its the pac200, they think that my car cannot charge the second battery. now i dont know if i misunderstood this but he then told me all i need to do is fully charge the battery with a battery charger then after that it should work fine and my car will be able to maintain charging it from there. he said i could also get a h.o. alternator an i told him i have a prius and there is no way that i kno of to upgrade it and he told me just to fully charge the second battery an everythign will be fine. so im going to autozone in a little bit. does this sound right to you?

Until you find out what you have, there is little point discussing.

You either have a relay like the PAC200, or a voltage-sensing relay/isolator maybe a PAC200 with controller (is it the BC-12 or similar?).


A relay is a switch - it is either on or off.
If off, there is no connection between the input and output.    

Do you hear it click on and off?

i just have the pac200 no bc-12.

autozone told me 45-60 mins so im waiting for the battery then i will listen for a click.

but my sub wouldnt work at all an the second battey wouldnt work at all either if the pac200 wasnt turning on. so im sure it is turning on. will up date in the next hour.

lol i fell asleep an they closed so i guess i will have to wait til tomoro to get my battery.

Apply 12 volts to the trigger terminal of the pac-200.  If the voltage is not equal on both large terminals, the pac 200 is defective.

If the voltage on the wire is only 6.8, that means whatever you are using to power that wire, can not handle the current demands of the coil.  You need to not turn it on again.  Find a new power source to trigger the pac-200

Agreed.

As I wrote before, disconnect the present 6.8V to the PAC-200 and jumper the +126V from the main battery (ie, its heavy contact).
If that does not energise the PAC200 & connect its heavy terminals, then it is faulty. (Assuming the PAC2-- ground and battery grounds are the same.)


The voltage of the second battery has no relevance (other than the spark/explosion risk I wrote before if it is that flat).

Even if it is a voltage sensing isolator, they usually only sense the main/primary battery voltage. Very few sense the secondary battery voltage - that is usually only done when the user wants to charge the secondary battery from another charger and hence also charge the primary battery (thru the isolator).


And if it is simply a PAC-200, I wonder why anyone would suspect it isn't a PAC-200?
And if it is a PAC200, the charging has nothing to do with it. It simply needs 12V (or 10V whatever) to energise it.

If your alternator cannot maintain its output at reasonable RPM, then you may have a undersized alternator (or the dc-dc converter from the Prius main battery - ie, the x00V bank). But I see nothing that suggests that.

ok i got my batttery back but it has been raining all day so i havent been able to put it in. but from the recent posts im understanding that getting it charged doesnt matter. so hopefully tomoro is nice so i can put the battery in then run jump a wire from the main 12v to the acc slot on the isolator. hopefully that works, i too think thats what the problem is. i will update once i do that. then my new task will be to find a 12v switched that i can tap into to run to the isolator. thanks for all the help

Or have that audio-on power a smaller relay that supplies 12V to the PAC-200. That's if it is simply the PAC-200 taking too much current from the original switch/control.

Normally battery isolators are powered from the charge lamp (as per the UIBI) else smart, intelligent, voltage sensing etc battery isolators if you don't have a charge light or similar circuit available.
When isolators are controlled by ignition switches (IGN or ACC) or HUs & amps, the risk is forgetting to turn them off....

ok sorry between work and the rain i havent got a chance before now to test it. so i ran a wire from the + terminal on the main battery to the acc terminal on the pac200 and turned the car on. i got over 13v on both terminals(big terminals) of the isolator. so that acc wire is the problem. i tested it at the jl amp as well and the amp seems to run fine even know the remote wire is only 6.8v. but now i need to find a new 12v switched that is actually 12v to run to my jl amp and the isolator. it started raining again while i was testing everythign so i guess i shall try to find a better 12v switched another day. right now the remote is off the 12v switched from the factory jbl amp. im guna try to find a 12v switched in the trunk so that i dont have to go tearing apart my dash and running the wire etc.

ok update****** so the rain was off and on so i took a chance to get this done. the remote wire that tapped into my factory amp an went to my amp and isolator...... i disconnected it from the factory amp wire and extended it an ran it to the 12v socket in the center counsel(which is switched). after testing the connector i then connected the remote wire to the switched wire on the socket. i turned the car on and everythign at the isolator was perfect and everythign works great.


Thank you guys soo much! :)