pplblazerdude
1/2 ton status
Since the comment of a better alternator has been brought up. What is everyone running. Currently I have the stock denso 10si case I do believe a 3 wire. What does everyone recommend?
CK5
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Dual Battery setups
- Thread starter pplblazerdude
- Start date
Jester1
1/2 ton status
I run a napa 105 a lifetime warrenty. Not that I need it yet but as I customize my wife rig it may be required, and when her old one went out I upgraded it for 15-20 bucks more like 8 yrs ago. IIRC.
to the top for more opinions/discussion. 
I've got a second battery and want to look into this stuff more.
I've got a second battery and want to look into this stuff more.
I was running a dual battery system with a diode isolator to support my winch and offroad head lights... until there was a short in the system somewhere and my alternator, both batteries, and isolator all got fried.
I did some research on a new setup and instead of the diode isolator, I went with a "smart relay" or "automatic charging relay". It's a newer form of technology than the diode isolator system. This is the one I got - http://bluesea.com/category/2/productline/overview/387
The install was very easy, and there are a few benefits. It is supposed to protect the charging system from itself if there is a short... i.e the battery can't ruin the alternator like my original setup allowed. Also, the charging is more efficient... with the diode system you get a voltage drop, which doesn't happen with the smart relay.
The one downside to the smart relay is there is a small constant current draw on the battery. However as long as you drive your car every so often and don't let it sit for a year it shouldn't be a problem.
I did some research on a new setup and instead of the diode isolator, I went with a "smart relay" or "automatic charging relay". It's a newer form of technology than the diode isolator system. This is the one I got - http://bluesea.com/category/2/productline/overview/387
The install was very easy, and there are a few benefits. It is supposed to protect the charging system from itself if there is a short... i.e the battery can't ruin the alternator like my original setup allowed. Also, the charging is more efficient... with the diode system you get a voltage drop, which doesn't happen with the smart relay.
The one downside to the smart relay is there is a small constant current draw on the battery. However as long as you drive your car every so often and don't let it sit for a year it shouldn't be a problem.
badmix
1/2 ton status
Im running a Mean Green 100amp alternator. Ive had it for 8 years or so. Going strong. I had to some kind of adaptor plug for my HellRoaring box to connect to alternator, I dont have the 1 wire setup.
gmule
1/2 ton status
I had this set up on my Dodge for 10 years without any issues. I am going to put the same on my plow truck now that I have the Alternator issues sorted out.
The aux battery on the Dodge ran my winch stereo and aux lights the main battery was truck only. It is nice to be able to winch a dead truck out of the water and still have enough juice to get it running once you winch it out or to be able to combine the batteries for an extened period of winching if you get really jammed up somewhere.
I put this together for less than a 100.00 using a continous duty solenoid and 3 position toggle switch with the appropriate wire gauge. Up on the switch is both batteries combined center position is both charging all the time and all the way down is self jump starting.
The aux battery on the Dodge ran my winch stereo and aux lights the main battery was truck only. It is nice to be able to winch a dead truck out of the water and still have enough juice to get it running once you winch it out or to be able to combine the batteries for an extened period of winching if you get really jammed up somewhere.
I put this together for less than a 100.00 using a continous duty solenoid and 3 position toggle switch with the appropriate wire gauge. Up on the switch is both batteries combined center position is both charging all the time and all the way down is self jump starting.
utherjorge
1/2 ton status
I keep thinking that there's no perfect setup.
I want a dual battery.
I want to be able to switch if one dies on me and go off the other one to start.
I do not want a constant draw on either/both.
I want to have extra power as needed with a minimum of fuss: I do not expect to use a winch, but aux lights? Sure.
I feel like I sound like Spaulding asking for a hot dog. Am I going to get nothing and like it?
I want a dual battery.
I want to be able to switch if one dies on me and go off the other one to start.
I do not want a constant draw on either/both.
I want to have extra power as needed with a minimum of fuss: I do not expect to use a winch, but aux lights? Sure.
I feel like I sound like Spaulding asking for a hot dog. Am I going to get nothing and like it?
badmix
1/2 ton status
What you want is EXACTLY what I have. I have the HellRoaring system.
It has a 3 position switch in the glove box.
1) Switch down - takes 2nd battery out of charging circuit
2) Switch in middle - Alternator charges both batteries but no draw on the 2nd battery even if there is a "draw" on the primary battery
3) Switch up - Alternator charges both batteries AND combines the 2 batteries for extra power.
If you do decide to go with the Hellroaring system, call them up and tell them what you want to do. Im using my 2nd battery strictly as a backup, there are no accessories feed off this battery. Im running 1 yellow top and 1 red top optimum. I want my 2nd battery to have no draw or being used for anything, so if I kill my primary, my 2nd battery is always fresh.
I think I pretty much said the same thingA big alternator does not do any good if you can't start your motor. I run two batteries and they serve me well. When my key is in the off position, the solenoid disconects my aux battery. I have left my headlights on and drained my main battery. I open my hood, switch the solenoid to self-jump, and start my motor. Tell me, how is a bigger alternator going to help me in that situation?
My alternator is just fine and charges my system adaquetly. I was just after the extra battery capacity and back-up battery security. That is what I took from the OP question as well.
You usually need a larger alternator because by adding a second battery you are reducing the overall current available to the charging system. i.e. car running. A second battery is a net load on the charging system. It's not a net gain. If your concern is just having a "spare" battery for when you run your main one dead then connect a solenoid on a switch. Charge the battery up then leave it disconnected. No reason to continually charge a fully charged battery. When your main battery goes dead flip the switch and start the car.
gmule even drew you a diagram
If your really looking to upgrade the entire system, then I would upgrade the power and ground wires in your car first. Then upgrade the Alternator to a higher current setup. Then add a second battery on a solenoid. No diode isolators. They burn out and as mentioned there is a small volatage drop.
I came here to post this exact thing. I did this with a Blue Sea ACR and battery switch. I keep the switch hard wired so I can self jump, and wire the ACR through another set of heavy duty cables.
Funny you mention the drain on the battery because I never knew about it or had it come up as a problem/concern -- I've let my truck sit for about a week and a half at times and the battery never fails to crank the truck up on the first try. Maybe it would be a concern if you stored your truck for months or a year straight, but for those of you who drive your truck on a semi regular basis it shouldn't be an issue.
Another plus of a ACR as opposed to an isolator is that there is no current drop with the ACR -- I started with an isolator but there was a pretty significant voltage drop between the input and output, but it may also have been because it was just a NAPA item, nothing fancy.
http://www.google.com/products/cata...=1&ie=UTF-8&tbm=shop&cid=12400252865774156302#
bellbrandon83
Newbie
Diodes have roughly a .7 volt drop, but there will be no current drop.
I=V/R Where V=Voltage R= impedence of load I=current
If voltage drops current drops.
bellbrandon83
Newbie
Current flows, voltage drops. Always remember that. Also R equals resistance in the ohms law you are referring to. The current in the whole circuit would be slightly higher without the diode, but not enough to effect anything. Voltage will drop by .7 volts across the diode, but current will never drop across any component. Thats basic DC circuits. Im an electrical engineering student, had those classes last spring.
Not all diodes. Most good isolators use Schottkey diodes, wich will be 0.3-0.4, although it does vary with the load through it. The only problem with the drop is the heat dissipation. The voltage drop can be compensated for by putting a similar diode on your alternator sense line. Some isolators have this built in.
My first dual battery setup had no wiring. I just put a DS tray in and put a battery in it and charged it every month or so. This was a backcountry backup - just swap the two batteries. Easy peasey and fulfills the purpose.
Now I run a marine battery for aux with it's own seperate fuse block for the accessories. Marine batteries are not true deep cycle batteries but are "close enough" to use like this, cost way less and still offer enough CCA to start your engine if needed. Alternator 1 charges just the main battery while alternator 2 charges both through an isolator. The 75A isolator is much cheaper and smaller than the 150+ unit that would be required with both alts through it. This is cheap and simple with no switches to tend to.
TheBeast_88K5
Banned
I bought a SurePower Battery Isolator.
Then, wired it to a battery selector.
Simple as could be.
Hardest part, is running the wire to the batteries.
Srsly.
Then, wired it to a battery selector.
Simple as could be.
Hardest part, is running the wire to the batteries.
Srsly.
I'm in a mood, so I figured I would jump in and stir things up.....
If voltage drops, often current increases.
As long as W=V x I and W is constant. This is why you can burn a motor up with low voltage.
The voltage drop across a semiconductor junction is different than the voltage drop across a resistance.
That drop is the turn-on voltage for the junction, and is independent of the current drawn.
Its a constant voltage drop.
For a silicon junction, .7volts is the most common. Germanium junctions are in the .2 to .3 range.
Most of the cheap power diodes are .7 volts. Some of the later designs have different drops.
And, don't forget, its .7 volts per diode. If you stack diodes for some reason, you lose .7V each.
If you wire the isolator so that the voltage sense line is on the other side of it from the alternator, then it becomes a non-issue. Since the alternator will put out enough voltage to maintain the correct voltage at the sense point.
And R can stand for impedance, but Z is more common.
But, in this case since we are dealing with DC, there is no impedance after the circuit reaches full voltage.
However, you can talk about input or output impedance even when there is no inductor or capacitor in the circuit.
If voltage drops, often current increases.
As long as W=V x I and W is constant. This is why you can burn a motor up with low voltage.
The voltage drop across a semiconductor junction is different than the voltage drop across a resistance.
That drop is the turn-on voltage for the junction, and is independent of the current drawn.
Its a constant voltage drop.
For a silicon junction, .7volts is the most common. Germanium junctions are in the .2 to .3 range.
Most of the cheap power diodes are .7 volts. Some of the later designs have different drops.
And, don't forget, its .7 volts per diode. If you stack diodes for some reason, you lose .7V each.
If you wire the isolator so that the voltage sense line is on the other side of it from the alternator, then it becomes a non-issue. Since the alternator will put out enough voltage to maintain the correct voltage at the sense point.
And R can stand for impedance, but Z is more common.
But, in this case since we are dealing with DC, there is no impedance after the circuit reaches full voltage.
However, you can talk about input or output impedance even when there is no inductor or capacitor in the circuit.
I'm in a mood, so I figured I would jump in and stir things up.....
If voltage drops, often current increases.
As long as W=V x I and W is constant. This is why you can burn a motor up with low voltage.
The voltage drop across a semiconductor junction is different than the voltage drop across a resistance.
That drop is the turn-on voltage for the junction, and is independent of the current drawn.
Its a constant voltage drop.
For a silicon junction, .7volts is the most common. Germanium junctions are in the .2 to .3 range.
Most of the cheap power diodes are .7 volts. Some of the later designs have different drops.
And, don't forget, its .7 volts per diode. If you stack diodes for some reason, you lose .7V each.
If you wire the isolator so that the voltage sense line is on the other side of it from the alternator, then it becomes a non-issue. Since the alternator will put out enough voltage to maintain the correct voltage at the sense point.
And R can stand for impedance, but Z is more common.
But, in this case since we are dealing with DC, there is no impedance after the circuit reaches full voltage.
However, you can talk about input or output impedance even when there is no inductor or capacitor in the circuit.
Was just about to post that too, but you beat me to it...
bellbrandon83
Newbie
I just didn't see the need to go into detail about turn on voltage and different types of diodes. I know that before I had these classes I would have had no idea what all that meant
StreetshocK
Registered Member
Relocated two batteries to the rear of my Blazer.
I have had the diode problems, and I've had problems with the 100% duty cycle solenoids before.
The easiest thing for my cheap-ass to do was to have a separate high current battery on/off switch (like a drag car) for each battery (on the ground wire).
Wiring to the engine vs. accessories vs. which battery draws doesn't matter. The whole truck can run off each (or both) batteries.
It also allows me to use them to weld without removing them from the truck.
I leave both on for normal driving so they are charging. When I'm off-roading or camping, I leave one on to have the other as a fully charged spare, in case I forget the stereo or lights. When I store it, I just click off both switches. You could do the same with a dual battery switch from a boat.
Can I still forget? Sure, but at least I will be my fault and not a broken part
BTW, I run a red top (for CCA) and a yellow top (for amp/hr). Best of both worlds!
Important side note! If your alternator has a separate "voltage sensing" wire (2 wire plug on the side) don't just stick it on the Alt output. It's a much better idea to run it to the fuse block, or even the battery if the battery is a long way away. The alt will now regulate the voltage at that point instead of right at the output.
I have had the diode problems, and I've had problems with the 100% duty cycle solenoids before.
The easiest thing for my cheap-ass to do was to have a separate high current battery on/off switch (like a drag car) for each battery (on the ground wire).
Wiring to the engine vs. accessories vs. which battery draws doesn't matter. The whole truck can run off each (or both) batteries.
It also allows me to use them to weld without removing them from the truck.I leave both on for normal driving so they are charging. When I'm off-roading or camping, I leave one on to have the other as a fully charged spare, in case I forget the stereo or lights. When I store it, I just click off both switches. You could do the same with a dual battery switch from a boat.
Can I still forget? Sure, but at least I will be my fault and not a broken part
BTW, I run a red top (for CCA) and a yellow top (for amp/hr). Best of both worlds!
Important side note! If your alternator has a separate "voltage sensing" wire (2 wire plug on the side) don't just stick it on the Alt output. It's a much better idea to run it to the fuse block, or even the battery if the battery is a long way away. The alt will now regulate the voltage at that point instead of right at the output.
