Relay Isolator vs. Diode Isolator (1 Viewer)

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MANUCHAO

MANUCHAO

omnia mea mecum porto
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Im looking at doing a double battery set up....
Not knowing much about this, I know I want to keep it as simple as possible...
Can any body comment on the pros and cons of these two Isolators ?

I take it the Diode isolator is better..as it regulates the power from the alternator and it provides the most power to the battery that needs it the most.... right ??

Pros, cons ???/


Thanks in advance...
 
Diode = voltage drop, hard time fully charging specially with the cheaper ones. I am about to do my double battery on mine and I am going to do it the way it did it one my other vehicles. Either a big manual switch/ isolator (you can get like 400amp ones and HB for cheap) Or the relay route so you can control it in the cab.

Just make sure you wire the relay the way that is least likely to wear your batt down wile the switch is on. Does that make since? so always closed will more then likely be "off" on your cab switch so if you leave your cruiser for a week or two you don't drain your batt. I did this when I turned off the truck and built the suspension for a couple weeks, before realizing I left it on the WVO tank and just that little bit wasted the battery.

But always, the Simple turn switch under the hood is the simplest and least (basically no extra) wiring.

Edit: As well with a Diode you can't use the batt except for auxiliary stuff, won't help winch, start the truck ect. so it kind of depends on what you want, if you want it just like a camper, and don't want to worry about switching or forgetting then Diode would be best for you.

Hope that arms you with enough info haha
 
Diodes have a small voltage drop. Relays do not. Unless the alternator's voltage regulator monitors the voltage, ideally, at the battery, or not quite as ideally, downstream of the diode isolator the batteries will never see a full charge.

There are constant duty solenoids (BIG relays) and there are automatic relays. The constant duty solenoids pre-date the diode isolators and are still a better option though the automatic relays are better still. I don't buy the marketing for those semi-automatic relays that have a remote switch. I prefer to use a robust marine battery switch for those needs.

The Automatic Charge Relays and Voltage Sensing Relays (different names for essentially the same product) don't have any voltage drop and do something that the diodes can't. They allow the alt. to first bring the starting battery back up to full charge before connecting the 'house' battery to charge it. Diodes force the alt. to charge both at the same time, even when they are not at the same state of charge. Relays also disconnect when the charge voltage drops, be that because you turned the engine off or there was some large draw on the starting battery.

There are two versions of the ACR/VSR's, single sensing and dual sensing. Single sense relays only sense the voltage from one side. Dual sensing look at both sides. With a single sense relay set up to allow the alt. to charge the 'house' battery last it will never turn on when the solar panel has charged the 'house' battery. A dual sense relay will allow solar or any other charge system connected to the house battery to charge the starting battery once the house battery is fully charged.

Can buy an ACR/VSR in combination with a marine battery switch so that you can force the two batteries to be paralleled or even switch the starting chores to the house battery if need be. This combo is what I would buy were I going to do it again.
 
Those that ntsqd posted are probably the best options, most expensive and complicated too. (For some who wants to keep it simple)

Simple, cheep and appears to possible be what the OP is going for (but I dono)
Heavy Duty Battery Cutoff Switch

Please note I don't know the amp rating on this. I would say that too depends but what you will be using it for aka winching, go 300+ camping ect 100amp rating would probably be good. (if using stock alt)

Also don't let something you don't quite understand stop you from getting what you really want, or whats your best option. people will talk you through it. Ntsqd posted the Best options as long as the amp rating for those products is high enough.

So what will you be using it for?
 
With the Hellroaring, I could combine the batteries for winching or starting, or isolate them for running my fridge and other accessories. Simple to install, totally solid state, very compact form factor, weather proof... Really, does it get any simpler?

I've installed switch and relay isolators and National Luna systems on customer vehicles, and I still prefer the Hellroaring system.
 
Sorry didn't mean to leave your system out ts888. All good stuff each person is different. For some people a simple isolator switch or relay is better then spending 200$ or more.

Wonder what the op's uses are for?
 
TS888 said:
With the Hellroaring, I could combine the batteries for winching or starting, or isolate them for running my fridge and other accessories. Simple to install, totally solid state, very compact form factor, weather proof... Really, does it get any simpler?

I've installed switch and relay isolators and National Luna systems on customer vehicles, and I still prefer the Hellroaring system.
Click to expand...

What're your thoughts on the IBS dual battery system? That's what I've been looking at for when I eventually go dual.

IBS -DBS Dual Battery System with Microprocessor - Sierra Expeditions (no affiliatioin)
 
For winching the ONLY combining switch that I would use is a marine battery bank switch. Of all of the options that I've seen the smallest form factor is the combined VSR/ACR & battery bank switch. They're also the simplest to connect, 3 cables and a ground reference wire. By using a manual battery switch in parallel with any type of charging relay you build redundancy into the system. Simple fixes for a field failure should one happen.

ACR/VSR's start around $75 with the marine switches starting around $40 Most of the more exotic options are quite a bit more. I like simple and robust, so the fancy options have no appeal to me and I know that the good marine brands will be more robust than anything marketed to RV's etc.
 
Thanks for the input guys...
The use of the second battery will be mainly for Fridge, Auxiliary fuse box and Fog lights....
Winch would be attached to the main battery...

I have looked at the IBS and NL but I dont see me spending $300 plus on a dual battery set up....

My Alternator is rated to 160 amp... but in real life is probably around 140 amps...

Automatic Charge Relays and Voltage Sensing Relays seem to be what I want to run...
Any idea where I could get one of these units at a good price...

Thanks guys !!
 
snowboardonsnow said:
Just make sure you wire the relay the way that is least likely to wear your batt down wile the switch is on. Does that make since?
But always, the Simple turn switch under the hood is the simplest and least (basically no extra) wiring.
Click to expand...

It doesn't which means I need to read up a lot more on it.... but thanks for posting up.. yeah the simple switch seems very easy..

snowboardonsnow said:
Edit: As well with a Diode you can't use the batt except for auxiliary stuff, won't help winch, start the truck ect. so it kind of depends on what you want, if you want it just like a camper, and don't want to worry about switching or forgetting then Diode would be best for you.

Hope that arms you with enough info haha
Click to expand...
Leave it to me to forget about turning something on or off... is like when I did an axle rebuild.. I put the race on and then the seal went on totally forgetting about the bearing..:bang::bang: lesson learned... ( I think).. I know Im forgetful so I have to watch out for that...
 
Blue Sea makes quality parts.
 
I prefer the simplicity of a relay (solenoid) system. I've been using them for 25+ years on trucks and such for trailer battery charging circuits.

It sounds like this would be a good set-up for your application, just make sure to have a thermal breaker in the charge line. The system is cheap, butt reliable, and basically fool proof. If your main battery fails you can use jumpers to start your truck from the aux battery, not as slick as a solid state switch but then how often does a well maintained truck need a jump start? And your probably going to carry jumpers anyway to help other people out.

Did I mention cheap? The relay runs around $30 and a thermal breaker about $15. With the money you have left from not paying for a solid state system you can buy beer or something.
 
The thing that people tend to forget about various multiple battery isolation methods is that even though the alternator can put out XXX amps, you don't really want the batteries being charged at that kind of current. The reason that alts can put out so much current is to stay up with the demands put on the system without having to borrow from the battery. So the isolator doesn't need to be able to carry starting type current loads. To be safe it needs to carry the max that the alt. can produce, but ideally you're charging at a much lower current. If you insist on one device does all things, which I think is a bad plan - what do you do when it fails?, then it will need to be able to support starting currents. If you build in redundancy to the system then dealing with a failure or an unusual situation becomes a simple thing.
 
snowakii said:
best electrical performance .. perfect switch

POWER-GATE, The World's Smallest and Most Efficient High Current MOSFET Array Solid State Relays, Battery Isolators, Low Voltage Disconnects, OR'ing Diodes, and Circuit Breakers

not cheapest.. but least votage drop
Click to expand...

Don't know about the others but I've got a perfect switch(Power Gate 200 amp) and it get's in excess of 13.5 volts at both battery arrays every time I've checked it. If there is a voltage drop it's not affecting charging either set of batteries, at least in my rig. :)
 
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