Good info buddy. I guess you would pick a solenoid equal to or greater than your secondary battery rating? Or a combination of primary plus secondary? I am an electric moran.
Planning a dual battery setup and accessories
- Thread starter Anthony.L
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Here is the way I look at it:
1. Even running a fridge on an 80 degree day/night, your battery is likely to see little drain, especially since most specialty fridges (norcold, engel, arb, etc) are designed for super high efficiency, resulting low amp draw. Cheaper units (edgestar, etc) marginally consume more power.
2. The added advantage is what I like to think of as cheap insurance in the event of a dead battery.
3. Separating circuits ensures that your primary battery does its job while the aux was doing what it's supposed to do all day/night.
4. In addition to this, long term, if you're planning on running lots of stuff for extended periods, by going with a deep cell battery, you are again using something that's specialty built, and designed to be powered down completely and take a charge time after time. Sure there are lots of other solutions for a high quality primary that's dual purpose, but again it's insurance/redundancy to help if needed
5. While I haven't needed to do so, you can jump yourself. As long as you have a set of cables, save the $80 that most vendors charge for the solenoid to remotely link batteries, such as with my IBS system.
6. I also like the fact that if I'm having any sort of mechanical issues, I can provide all the lighting I need, along with two batteries worth of cranking to identify/fix the issue.
In retrospect, very few of us (including myself) really NEED a dual battery setup, but for the $600ish I have in mine, it's the way to go.
When it comes to sourcing parts, Genuine Dealz (an ebay store) has a wide selection, at good prices. You can even have then build you custom cable setups.
Think of it this way... How many people do you see out there with jerry cans hanging all off their Jeep and FJ that are never likely to get any more than 20 miles off the beaten path????
A dual battery setup provided me flexibility to have a completely independent circuit, without tapping into primary power supply or circuity - and developing any parasitic drain, or anything else otherwise compromising the factory power grid.
1. Even running a fridge on an 80 degree day/night, your battery is likely to see little drain, especially since most specialty fridges (norcold, engel, arb, etc) are designed for super high efficiency, resulting low amp draw. Cheaper units (edgestar, etc) marginally consume more power.
2. The added advantage is what I like to think of as cheap insurance in the event of a dead battery.
3. Separating circuits ensures that your primary battery does its job while the aux was doing what it's supposed to do all day/night.
4. In addition to this, long term, if you're planning on running lots of stuff for extended periods, by going with a deep cell battery, you are again using something that's specialty built, and designed to be powered down completely and take a charge time after time. Sure there are lots of other solutions for a high quality primary that's dual purpose, but again it's insurance/redundancy to help if needed
5. While I haven't needed to do so, you can jump yourself. As long as you have a set of cables, save the $80 that most vendors charge for the solenoid to remotely link batteries, such as with my IBS system.
6. I also like the fact that if I'm having any sort of mechanical issues, I can provide all the lighting I need, along with two batteries worth of cranking to identify/fix the issue.
In retrospect, very few of us (including myself) really NEED a dual battery setup, but for the $600ish I have in mine, it's the way to go.
When it comes to sourcing parts, Genuine Dealz (an ebay store) has a wide selection, at good prices. You can even have then build you custom cable setups.
Think of it this way... How many people do you see out there with jerry cans hanging all off their Jeep and FJ that are never likely to get any more than 20 miles off the beaten path????
A dual battery setup provided me flexibility to have a completely independent circuit, without tapping into primary power supply or circuity - and developing any parasitic drain, or anything else otherwise compromising the factory power grid.
Stan is correct. The only real benefit of a T-max or IBS controller is the ability to isolate you batteries automatically when the engine is shut off. I've manually linked my batteries and self jumped etc, but you really don't need a controller to do that.
When the batteries are linked, the alternator sees them as one big battery. It's not smart enough to only charge your aux battery etc.
I'm beginning to wonder if battery controllers give a false sense of security?
When the batteries are linked, the alternator sees them as one big battery. It's not smart enough to only charge your aux battery etc.
I'm beginning to wonder if battery controllers give a false sense of security?
They do a pretty good job of passively feeding the starting batt only until the voltage hits a predetermined point and then also passively disconnecting them after shutdown. The entire strategy is to prevent you from becoming stranded with a flat starting batt. True you could do it all manually, if you remember every time.
I think they do, unless you know and understand what you're looking for and how to use it. If you need to see lights, I like this do-hickey from Slee
http://www.sleeoffroad.com/installation/battery_led.pdf
The mounting of the LED boxes on dashboards and consoles makes no sense to me. Why would you want more stuff to hit, break, look at or take up space? Once the truck is running the box will always show the same thing anyway. Correct?
Craig knows waaay more about this kind of stuff than I do, but you don't need a battery controller to run a dual battery setup. People have been doing that for years without the $400 LED boxes of today.
Granted, my setup isn't as fancy as the IBS/TMAX ones and I have to open my hood and flip a switch when I get to camp...... But essentially it does the exact same thing. Just gobs cheaper and dummy proof for dummies like me.
paflytyer - The T-Max dual controller is $123 from Amazon, so really isn't that much more than your setup. I completely agree that it seems like the IBS system is overkill and likely overpriced. I don't need the blinking lights of either setup to be prominently displayed, but it'll be just fine either in the glovebox or hidden in the center console.
I paid for the IBS. I mounted the monitor in the center console. It was very easy to install and came with everything needed.
I will note that their instructions did not advise to connect the negative poles on the batteries, just ground the second one to the frame/body. That is what I did.
Heifer-net
I will note that their instructions did not advise to connect the negative poles on the batteries, just ground the second one to the frame/body. That is what I did.
Heifer-net
I think I would question the statement that the indicators only show alternator voltage. If voltage were a constant 14.1 whenever the alt was running then lights wouldn't dim when the fan was turned to high nor would the voltage sensing switches isolate to the primary battery until above 13.7. The indicators show the voltage of the system. There will always be some drop under load. True, that 95% of the time, a healthy system will achieve alternator voltage shortly after start and remain there, making constant monitoring mostly irrelevant, especially with the factory gauge. But we don't monitor for normal, we monitor for failure.
If you take the LCD box of any dual battery management system and touch the (+) to (+) and (-) to (-) on your running vehicle with only one battery, it's going to light up both sides of the box. Correct?
I agree with you if running a stock alternator. My lights don't dim under any conditions with my new alternator.
The statement from another post about the LED's is only accurate if you wire the display panel to only come on with the vehicle running. The way I did it, I can monitor both batteries separately when the truck is off and the key is not in the ignition, this way, when camping and actually using the aux battery I can monitor it's state of charge. With the Iron Man DBS ($275) the alternator will only charge the main battery when the vehicle first starts and you can also see this on the display. Once it detects a suitable charge level for the starting battery, it combines the batteries and charges both. If I shut my truck off at camp it automatically disengages the main battery from the aux, and I am guaranteed to never forget to flip a switch and drain my starting battery. It was worth the extra money to me to have a solution that I didn't have to remember to use.
No. Only when the batteries have been combined. If the batteries have not been combined you get the accurate reading off of each battery.
Most of us are using dual battery systems so we can drain down one battery without the vehicle running, yet still be assured of being able to start the truck with the main battery. The LED display is used to monitor your aux battery voltage and to know when it is time to turn on your rig to charge the aux back up.
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There is more to the controllers that just a simple switch. Yes, when the truck is running you show the charge voltage going to both batteries, and yes it should show the same. It does indeed not show the voltage of each battery separate. However when not running (batteries are disconnected) the IBS or our LED lights is a quick way to verify voltage at each battery.
The larger issue is what happens when you have drained the 2nd battery and then start the vehicle. What will happen a simple voltage based combiner will see the alternator voltage, then combine the batteries. Then the additional load of the 2nd drained battery on the system when it is combined drops the alternator voltage and then the combiner drops the link. It can go into what I call a "flutter" mode when it repeatedly does that. I have experienced that personally with a Blue Seas ACR.
The IBS system has timers in it that prevents this from happening. It also has timers in it to prevent the link from dropping out when you do quick repeated starts and stops thus eliminating wear on the contacts of the relay.
In addition, it is automatic with really no drawbacks other than the size of the controller and how to mount in modern vehicles. That is why we developed the small LED solution. We have a new version coming out that is even smaller and some additional features. It will actually mount behind a switch blank and the LED's are mounted to the circuit board, so it is a very small form factor.
The larger issue is what happens when you have drained the 2nd battery and then start the vehicle. What will happen a simple voltage based combiner will see the alternator voltage, then combine the batteries. Then the additional load of the 2nd drained battery on the system when it is combined drops the alternator voltage and then the combiner drops the link. It can go into what I call a "flutter" mode when it repeatedly does that. I have experienced that personally with a Blue Seas ACR.
The IBS system has timers in it that prevents this from happening. It also has timers in it to prevent the link from dropping out when you do quick repeated starts and stops thus eliminating wear on the contacts of the relay.
In addition, it is automatic with really no drawbacks other than the size of the controller and how to mount in modern vehicles. That is why we developed the small LED solution. We have a new version coming out that is even smaller and some additional features. It will actually mount behind a switch blank and the LED's are mounted to the circuit board, so it is a very small form factor.
I agree with you if running a stock alternator. My lights don't dim under any conditions with my new alternator.
The statement from another post about the LED's is only accurate if you wire the display panel to only come on with the vehicle running. The way I did it, I can monitor both batteries separately when the truck is off and the key is not in the ignition, this way, when camping and actually using the aux battery I can monitor it's state of charge. With the Iron Man DBS ($275) the alternator will only charge the main battery when the vehicle first starts and you can also see this on the display. Once it detects a suitable charge level for the starting battery, it combines the batteries and charges both. If I shut my truck off at camp it automatically disengages the main battery from the aux, and I am guaranteed to never forget to flip a switch and drain my starting battery. It was worth the extra money to me to have a solution that I didn't have to remember to use.
I think the IBS has a "read" button that lets you get a true reading of both batteries when the truck is off. I'm not debating the merits of the system at all. It does what it was designed to do. The question was asked about a simpler system, which is what I have. I actually bought the IBS system, but after looking at it I decided to build a simple no fail system for my needs. If I fail to isolate the aux battery by flipping the switch, then I run the risk of draining both batteries. That's the downside, so it's just become part of my routine when I camp. However, it's mostly just my fridge that's running all night and that draws such a small amount that even if I forgot I'd still be fine.
I was with a guy on the Kokopelli this year who's relay stuck open on his IBS system. Since his HAM, CB and fridge were run off the aux and the relay was open, it ran his aux battery dead on day 2. We figured out what was going on by using my cheapie volt meter. He started the truck and hit the link button on the box while I tapped on the relay and it snapped closed and charged the aux battery. It's not a fool proof system either. Like anything else, if you don't understand how/what it does it could leave you just as stranded.
I was in no way saying one is better than the other.
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Not true. Try it. You don't even need a second battery to get a two battery reading when the truck is running. If you shut the truck off, it will show one.
Christo, I have to stop by this week anyway. Do you have that new LED display ready?
Christo, is this the ACR you were using? Using their switch looks like it would be easy to kill chatter by hitting the combine button.
http://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A
http://assets.bluesea.com/files/resources/instructions/990180180.pdf
http://www.bluesea.com/products/7622/ML-ACR_Automatic_Charging_Relay_with_Manual_Control_-_12V_DC_500A
http://assets.bluesea.com/files/resources/instructions/990180180.pdf
I am not talking IBS I am talking Ironman and you are incorrect. The LED display wires to EACH battery independently, so you will only get a reading if there is a second battery present.
If the truck is running and has been more than 10 seconds and the primary battery has a sufficient charge, then you will read alternator voltage for both batteries. If the truck is turned off, the batteries automatically disconnect (via stepper motor controlled solenoid, not a relay which means you can manually override either way even if the stepper motor goes out.) and you will read real battery voltage independently.
I am glad your system works for you, I went a slightly more expensive approach which was worth it to me based on what I wanted from my DBS.
In case you are interested, IronMan is only packages other components to make an easy system. The heart of it is this if you want to buy it separately.
http://www.bepmarine.com/home-mainm...dvs-high-current-remote-operated-vss-275-amps
http://www.bepmarine.com/home-mainm...dvs-high-current-remote-operated-vss-275-amps
I shouldn't have misspoken then. I tried it with the IBS system and could light both sides of the box before I even had a 2nd battery in the truck.
I wasn't trying to imply that someone else's system doesn't work, or that it wasn't worth the money spent. I'm not an electrician, mathematician or engineer. I talk to airplanes for a living. The question was asked about a simple system. I maybe went too deep into why I built a simple system as opposed to buying the more expensive ones.
When it comes to smarts on this forum, I'm probably in the bottom 10%, and that's ok. I get to explore a lot of cool places with cool folks and I haven't been stranded by my set up yet. I should bow out of this conversation because it's already over my head anyway.
It was a similar one, but without a switch for override in the cab.