Battery Isolator

[Havasu Hangin']

The reason a voltage drop is important is because of amplifier design.
For example, if you have a 500 watt Class a/b amplifier, and it puts out 500 watts at 13.8 volts, at 12.8 volts...it'll put out about 450 watts.
Most people compensate for the difference by turning up the volume. Instead of drawing 60 amps, that same amp (to reach 500 watts) will draw around 65 amps.
More amps = killing batteries faster.
As far as modifying the alternator for higher output...to me, that's kinda like putting nitrous on a car to make up for an air filter that is restrictive.
Installing a isolator to keep battery banks separate on an RV to run 12volt appliances is a little different than for a big stereo which begs for voltage.
If it were me on those trucks, I'd probably install a second alternator to isolate the workload.
Originally posted by cruser
So, how do you handle different battery banks at varying voltages?
I'm guessing the 6 volts are in series.

[cruser]

My comment was about the voltage on the batteries when partially discharged. I was concerned that a lower reference voltage might cause the fully charged battery to get over charged. But, after thinking about it a bit I see that any overcharging would be minimal if at all because the reference signal would be the same for all the batteries. just need to make sure the battery with the most discharge is used as the reference other wise it might take too long to charge that battery.
I just use a continous duty selinoid that is activated by an oil pressure safety switch. When the motor starts, the switch closes connecting the Aux batteries to the charging circuit. Sounds similar to the relay based ssytem discussed earlier in this thread.
cruzer

[Interceptor454]

Running the isolator, both the stereo batt's and the starting batt are registering 13.2 volts. I'll let you know how it works throughout the summer.

[Sweet Addiction]

Running the isolator, both the stereo batt's and the starting batt are registering 13.2 volts. I'll let you know how it works throughout the summer.
So now I have started working on my system, and I have a few questions about isolators. I don't know anything about them, but I am good at learning and have been doing systems for many of years. Just basic systems though. So I purchased a Kicker KX600 mono Class D and it will be pusing two Infinity Kappa series 10" subs. So what I need to know is, 1) What size isolator should I purchase 2) Will my stock alternator be enough to keep the batteries charged when running 3) What size circuit breaker should I run on this system.
Thanks Jared.

[ROZ]

IF you want use a Iso relay, use the PAC200 .. You can find it at www.pac-audio.com
Why not just use a Perko?

[Sweet Addiction]

IF you want use a Iso relay, use the PAC200 .. You can find it at www.pac-audio.com
Why not just use a Perko?
I am going to use a perko, but don't want to have to turn the switch all the time. Althought I am going to locate it under the back seat so I can access it with the hatch down. From what I understand I want to use an isolator so I can run both batteries for the system, and when one drops below starting voltage it shuts it off, and just runs the stereo off one battery. I think this is right but I may be wrong. I just don't want to run both batteries dead. Thanks for all the advice Roz.
Jared.

[Sweet Addiction]

bump :rollside:

[ROZ]

I am going to use a perko, but don't want to have to turn the switch all the time. Althought I am going to locate it under the back seat so I can access it with the hatch down. From what I understand I want to use an isolator so I can run both batteries for the system, and when one drops below starting voltage it shuts it off, and just runs the stereo off one battery. I think this is right but I may be wrong. I just don't want to run both batteries dead. Thanks for all the advice Roz.
Jared.
This item is available from a few companies, but I pulled this one from the West Marine site.
It automatically disconnects the battery when it drops just below 12v and reconnects the battery after the boatstarts...
http://www.westmarine.com/images/full/34430_f.jpg
It's 80.00 at west, but I've seen them for close to 50.00... i just can't remember where :220v:
You can run your perko and put this inline with your starting battery...

[Sweet Addiction]

Thanks for the advice Roz, I think I am getting the idea now, which puts me closer to making a decision.
Jared.

[Fashun]

In most of my installs, I have found that an Iso- relay works just as well as a battery Isolator. A company called Wrangler, which specializes in aftermarket charging upgrades, has a relay called the smart relay. What it is special for is that it waits until the main battery reaches a charging level of 13.5 volts then automatically trips to allow a charge to flow through to the auxillary batteries. This is nice, If you wire your auxillary electronics to the Aux. battery you will have comfort in that your main battery will always have a complete charge. It's idiot proof and works great. I have installed over 100 of them and never had a complaint or problem. I believe retail on it is around $150.00. Oh, yeah it is 200 amp capable. Good Luck.