Dual batteries

[Ehall8702]

You could also use a 200a able fuse block on each side of isolator if you are worried about it sticking , or circuit breaker whatever u choose. I know guys who fuse from alternator to the battery with big 4 upgrades, seen guys with fuses before and after rear battery banks, that's kinda overkill imho. I have dual batteries , dual runs of 3/0 welding cable throughout truck on every thing. I only use fuses between batteries and amplifiers in the back. I have a dual anl block with 2 450a fuses. In a sine wave my taramps md8k pulls just under 900a...I've been close to full pull quite a bit and never kicked a fuse or been worried about anything. I can't run an isolator with my setup tho, they don't make anything I can afford to carry the amps I'm pulling.

 

[Gramps]

And on the contrary I've had ford starter relays melt down on the side of the highway and actually had to piss on it to put it out cause we were traveling. We use em for plow setups up here and more often than not they stick closed or melt terminals off. You want a serious one, get ahold of boss snowplow and get one of thier isolators, they can be mounted in an orientation and and are heavily over rated. The ford ones you can only mount them vertical or they WILL stick. I've been installing for over 25 years and can only think of 3 or 4 stuck isolators I've put in, I only use pac or stinger stuff , the ford ones I've put in were usually brought by customer or I've used em on my stuff since Im way up in middle of nowhere and needed one right away and that's what u can get from parts store. Ultimatly it's personally preference tho.

again it’s because the ford starter relay is exactly that, for use starting the vehicle, it is NOT rated for continuous use. That’s why they melt down. Unfortunately a lot of the “parts stores” don’t know the difference either and if the customer doesn’t know either it’s the blind leading the blind with a lot of part blaming ie the “crappy ford starter solenoid that always burns up”

 

[Ehall8702]

again it’s because the ford starter relay is exactly that, for use starting the vehicle, it is NOT rated for continuous use. That’s why they melt down. Unfortunately a lot of the “parts stores” don’t know the difference either and if the customer doesn’t know either it’s the blind leading the blind with a lot of part blaming ie the “crappy ford starter solenoid that always burns up”

Ur exactly right, pull coil wire and hold ur key in start position and see how long it takes to cook that starter relay...not real long I'm sure. Wonder what thier duty cycle is? That's why I use isolators for audio applications,they have a 100 percent duty cycle. They make cheaper ones that are china spec and may melt down too. But yeah, blind leading the blind, half the time I have to provide part numbers to get right parts thru our local parts stores!

 

[GoToGuy]

Not to be rude, but all that amplifier speakers that make you deaf. Alittle off topic for dual battery upgrade or factory type install.. Have any of you actually looked at the charted graph showing what gauge wire is recommend suitable for your desired or anticipated load? I can upload if you want to see how to determine what size you need. Not just make everything 2 /00. ( two ot)

 

[GoToGuy]

Good tip do a little more research. Starter Solenoid duty cycle generally is 30 seconds on, 30 seconds off, 30 seconds on, 30 seconds off, 30 seconds on, then 30 MINUTES OFF. A starter solenoid is an "Intermittent duty cycle" switch. It is NOT a "Continuous Duty switch". Continuous duty rated for what your electric load system is designed for. You can allways take alot of cheapass shortcuts. Or how much is your vehicles reliabilty worth, or your wife and kids using your truck, suburban or yukon/tahoe. GM installed a 100 amp circuit breaker before the power distibution box/ center on high output alternator options.

 

[1ton-o-fun]

Just a reminder. I was asking about factory dual battery setups. I was not asking for opinions of why they’re unnecessary.

Mr. Petersen,
If you're not married, or if you're considering getting married...This thread is kinda what it's like. There's no such thing as a simple question or answer. Tons of great info and opinions here. Hope you get what you're looking for out of it. I've been reading and laughing, as I'm on my 3rd marriage. So I feel your pain, lol! Just keep in mind that the rest of the stuff in here may help others. I think it's helped me decide to stay single. -Um single good battery, that is.

 

[Steven Petersen]

Mr. Petersen,
If you're not married, or if you're considering getting married...This thread is kinda what it's like. There's no such thing as a simple question or answer. Tons of great info and opinions here. Hope you get what you're looking for out of it. I've been reading and laughing, as I'm on my 3rd marriage. So I feel your pain, lol! Just keep in mind that the rest of the stuff in here may help others. I think it's helped me decide to stay single. -Um single good battery, that is.

Yep, married 20 years now. Still on my 1st wife. Excellent point I hadn’t thought of. Some of these answers are exactly like trying to get a straight answer out of my wife. Impossible.

I’m leaning towards staying with a single battery, but not because of the off-topic opinions on here. What I have learned is a dual battery setup for starting purposes was never used on gas engines. Only for auxiliary purposes. Plus I don’t care for the 2nd cable routed across the fan shroud.

 

[Garage Hack]

Please... consider using a heavy duty CONTACTOR rather than an isolator. I had a really nice truck that I'd just dumped $15k into burn to the ground due to a faulty isolator that started an engine compartment fire while the vehicle was unattended, many hours after parking it. It was a very expensive Phoenix Gold model, carefully installed, with a current rating well above my intended usage.

The cheap/easy way to go about this is to use the extremely common Ford standalone starter solenoid. But there are higher end more expensive contactors out there if you prefer.

You can reap all the same benefits of using an isolator without the voltage drop drawbacks or the inherent risk of failure/meltdown/fire when using high current diodes that are likely sourced pretty cheaply these days.

Any idea about a part number or source for a "contactor" I have the PG type on my truck and want to get rid of it after hearing about your experience.

 

[GoToGuy]

In technical terms a solenoid generally is used as an electromechical device energized for a mechanical action. Think turn key starter solenoid energized causing bendix action starter motor activates.
A relay is an electrical switch. Which can be operated with a lower voltage amperage to close a contactor on higher voltage and or amperage. Say hit switch in cab to operate the relay running your aux radiator fans pulling 40 amps.on high. Or a Parker Hale, Blue Streak Standard rated at 200 amps ( or more) continuous, what does you equipment require? Using relays allows shorter runs of high load wiring. Less high amperage in passenger areas. No monster switches in cab. So if that helps great or oh well...