12 volt masters

[sleazebagger 10+ year member]

I have a XS d6500 and a 250 amp mechman alt.

I'm adding 3 BMW AGM's to the rear and two runs of 0awg.

My question(s) is: Should I use my 200amp stinger to isolate the bmw agms?

What size fuses should I be using between the ALT and Batts / Front batt to rear batts / Batt to amps?

I'm running 2 massive p3000.1's and an Audion lrx 6.9

Many thanks and praise will be given

Sims

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[sacsking916 5,000+ posts]

Fuse for the wire bro. And I have a pac-200 isolator if your interested

 

[sleazebagger 10+ year member]

Fuse for the wire bro. And I have a pac-200 isolator if your interested

what the hell is wrong with you boy?!!

 

[sleazebagger 10+ year member]

Id like to order all my fuses and wire today if anyone has some real experience with this.... Please share

Thanks much

 

[bubbagumper6 5,000+ posts]

If you already have the isolator why not use it?

Also, like sacsking said, fuse for the wire. So if your using OFC 1/0 then generally it's 300A.

 

[MONSONwarrior Premium Member]

If you already have the isolator why not use it?
Also, like sacsking said, fuse for the wire. So if your using OFC 1/0 then generally it's 300A.

This, and CCA is generally 250a. I was told you can use the isolator but you lose like .7 volts or something through the mechanical connection, so I wouldn't use one unless you leave your car sitting for long periods of time for the batteries to pull from each other. As far as batt to amps I'd do 300a to each one.

 

[sleazebagger 10+ year member]

This, and CCA is generally 250a. I was told you can use the isolator but you lose like .7 volts or something through the mechanical connection, so I wouldn't use one unless you leave your car sitting for long periods of time for the batteries to pull from each other. As far as batt to amps I'd do 300a to each one.

So if I plan on leaving my car sit for a few days or more then just disconnect the rear batts.

Sounds like a plan.

Thanks again

 

[sacsking916 5,000+ posts]

So if I plan on leaving my car sit for a few days or more then just disconnect the rear batts.
Sounds like a plan.

Thanks again

pretty much. if it aint gonna be run put a trickle charge on it or disconnect them is always an option. i havent driven my car in about a week, i just toss the charger on the batts every 2-3 days

 

[bubbagumper6 5,000+ posts]

This, and CCA is generally 250a. I was told you can use the isolator but you lose like .7 volts or something through the mechanical connection, so I wouldn't use one unless you leave your car sitting for long periods of time for the batteries to pull from each other. As far as batt to amps I'd do 300a to each one.

Adding electrical components in series will always cause some sort of voltage drop but .7 is fairly large, I can't imagine any decent isolator on the market has a drop that big.

 

[MONSONwarrior Premium Member]

Adding electrical components in series will always cause some sort of voltage drop but .7 is fairly large, I can't imagine any decent isolator on the market has a drop that big.

I understand that, I lose .2 between my alt and amp because of my two batteries but when I was looking into one that was the common figure I got when asking around about how much I'd lose. I was gonna buy one from Outsideshot23 and that's what he told me too.

 

[bubbagumper6 5,000+ posts]

I understand that, I lose .2 between my alt and amp because of my two batteries but when I was looking into one that was the common figure I got when asking around about how much I'd lose. I was gonna buy one from Outsideshot23 and that's what he told me too.

If that truly is the case I would take the extra 0.7V over the possible gains of an isolator any day.

Also your batteries are in parallel with the rest of the electrical system and thus won't cause the same kind of drop I'm talking about. Your probably losing that 0.2V because of resistance in your conductors/connectors.

 

[MONSONwarrior Premium Member]

If that truly is the case I would take the extra .7 volts over the possible gains of an isolator any day.

I'll probably end up installing one in school because my truck will sit for a week at a time. but right now I don't have a need since I drive it everyday.

 

[bubbagumper6 5,000+ posts]

I'll probably end up installing one in school because my truck will sit for a week at a time. but right now I don't have a need since I drive it everyday.

I don't like to give advice based on personal experience since every install is different but I've never run an isolator, ever. This includes multiple battery systems with different brands/sizes/ages. I've even left my lights on in my car overnight and I've literally never had to jump it.

I don't think an isolator will help you in the exact sense your looking for. If you want to play your system with the vehicle off for some reason it will keep you from draining your main starter battery, and in theory it will lengthen the life of the batteries by disconnecting them keeping them from trying to charge each other. But like I said, I've never run into a problem of a battery bank draining because it sat connected too long.

 

[MONSONwarrior Premium Member]

I don't like to give advice based on personal experience since every install is different but I've never run an isolator, ever. This includes multiple battery systems with different brands/sizes/ages. I've even left my lights on in my car overnight and I've literally never had to jump it.
I don't think an isolator will help you in the exact sense your looking for. If you want to play your system with the vehicle off for some reason it will keep you from draining your main starter battery, and in theory it will lengthen the life of the batteries by disconnecting them keeping them from trying to charge each other. But like I said, I've never run into a problem of a battery bank draining because it sat connected too long.

It's just what was recommended to me when I asked how to solve that problem. I'll just end up seeing how it goes when I'm in school, and maybe just disconnect the ground of the back battery to keep them separate.

 

[sacsking916 5,000+ posts]

It's just what was recommended to me when I asked how to solve that problem. I'll just end up seeing how it goes when I'm in school, and maybe just disconnect the ground of the back battery to keep them separate.

puttin the isolator in wont help for what you were talking about. the isolator only allows your rear batteries to discharge instead of your fronts. if the car is parked then the batteries will drain whether they are hooked up to the iso or not. like you said about disconnecting the battery grounds will keep them from discharging