I think my battery isolator crapped out... suggestions?

[Bbasso]

I've tested it, results I posted on the first post. All the wiring to the house battery and isolator are solid and performing properly. The out put of the isolator is low.

A few people have said to toss that model in the garbage. You are the sole voice in the crowd saying to keep...

Since I have dual alts I'm very sure my vans amp output is over 200.
I've yet to verify, but why would Ford only put in two 100amp alts when they could have done it with just one...?
My past 7.3 single alt vans had a 130 amp alt.
If my guess is correct, 260 amps coming from the van.
I honestly appreciate everyone's suggestions and help.

 

[4RunAmok]

If it were me. And I do this for a living...

I would do the Blue Sea 7622, a solar controller/panel hooked to the aux side.

The problem with the Blue Sea 7620 is there is no manual switch on the device itself.

The 7622 has the advantage of completely hands-free/mind-free/hassle-free automatic functionality. You need not worry about it's operation, after you start your vehicle, you will hear a "click" within 30 seconds or so, letting you know the batteries are combined and both are charging. If something has killed your starting battery, simply use the supplied switch you've mounted in your cab, and combine them to start your vehicle. Or ditch the switch, and plan on using the manual knob on the ACR itself to combine them temporarily so you can start.

The solar charger on the aux battery should keep it topped off so it's always ready.

NOW...

If you were willing to spend a bit more than this.. the CTEK D250S is a great way to do the solar as well as handle the isolation. This device has the advantage of using the solar to charge both batteries, in case you didn't buy a dual battery bank controller in my first suggestion.

Weasel is the odd man out now isn't he. He and I went back and forth in your other thread in this sub forum. Diodes are SH!TE, I don't care who ya are or how you use them. They CAN and DO fail, as you're discovering today. The Blue Sea can handle over 1000 amps at peak, and 500 continuously, I'd like to see a diode do that without exploding.

 

[CaliMobber]

Yea diodes are the cheap way of doing things, blue sea auto with manual is def my vote. Not only does the diode have a chance to fail, but it eats up a percentage of your charging power when it splits the power if I remember right.

 

[Weasel with a Diesel]

Now I have a good laugh about the man who starts every second post with: "I do this for a living!"

Instead of telling about people being odd, you should be able to give a brief decription of Bbassos problem, right?

You can't?

Ok, I will do so. As you know, as an "I do this for living" an diode isolator must compensate voltage drop. This is done either with an external regulator or with an diode isolator with an "R" input.
We do have an "R" input
An "R" diode isolator and a Ford. This alone should tell you that it is necessary to tap into the vehicle regulator.

Now the fail:
The input shows according to Bbasso 13.7V. This should tell you that either the regulator is defect, or the connection between "R" and the regulator has a problem.
As a "I do this for living" installer you should know that in Ford applications should/must be a fuse installed between R and regulator.
So the input voltage is not at the usual level of 15.2 V compensating for the voltage drop:
1. Regulator fail
2. R-Wiring fail
Sadly Bbasso hasn't given more information to trace it into detail.

I really do fear your garage business and experience, 4RunAmok...:bowdown:

 

[wrcsixeight]

If my guess is correct, 260 amps coming from the van.

Alternator ratings are figured out in a lab, when they are cold, spinning at very high rpm with devices asking for amperage in excess of the maximum through cabling that can pass that much current.

None of this ever happens in the engine compartment and certainly that much amperage will not flow into a regular flooded battery as it will not accept that much, ever. I suspect higher rated alternators are just better at handling the tremendous amounts of heat they create when running near their max. If one goes onto Balmar's website one can find that some higher rated alternators actually produce less amperage at lower speeds than their lower rated counterparts, so the bigger is better attitude is possible unjustified here too.

Also many people act like alternators are free energy. The alternator will consume about 1 engine HP for every 25 amps it is asked to produce. Hardly free. I can easily notice how much more free revving my 318 is when the batteries are fully charged.

I've been aware of the voltage compensating Diode isolators, but would never bother with on on my vehicle, and not only because the voltage regulator is internal to the engine computer. Also if the max voltage is artificially raised just so adequate voltage is making it to the distant aux battery, then that much more voltage is making it to the engine starting battery too, likely overcharging it. Also the mid 15 voltages are getting near the dangerous voltage territory for some electronics designed for 12v nominal. Like absorption fridge circuit boards.

So to me, an diode based isolator which requires one to modify the vehicles voltage regulation for proper charging voltage to make it into the auxiliary battery is unwise. I'd never do it when so many other options exist. If a vehicle I bought already came with one and it was not working as it should, I might try to troubleshoot it, but more than likely I'd get myself a good high rated continuous duty solenoid and trigger it by the blower motor circuit if I wanted something automatic.

Turns out I prefer the manual option and use Blue seas Mini switches to control all aspects of current flow in my vehicle, but my electrical wall would confuse many.

 

[Bbasso]

I'd happily give more details/info to help make a better decision.... but what would you like to know?
If a full manual switch isn't a bad idea I'd do it in second. I like being in control and always on top of the van's needs.

 

[Weasel with a Diesel]

I've been aware of the voltage compensating Diode isolators, but would never bother with on on my vehicle, and not only because the voltage regulator is internal to the engine computer. Also if the max voltage is artificially raised just so adequate voltage is making it to the distant aux battery, then that much more voltage is making it to the engine starting battery too, likely overcharging it. Also the mid 15 voltages are getting near the dangerous voltage territory for some electronics designed for 12v nominal. Like absorption fridge circuit boards.

Just a little correction needed.
The external regulator "sees" a lower voltage and increases in turn the alternator voltage.
As a result the pre- isolator voltage is higher. (Usually 15.2V)Then subtract the voltage drop in the diode isolator (about 0.7V) and the voltage at the output of the isolator is back to normal (14.5V).

The increased alternator voltage does never reach any circuit of the vehicle.
That's plain and simple the big mystery about diode isolators.

Trouble starts, (and your absolutely correct, wrc!) when you tap in right behind the alternator, spreading 15.2 V into the vehicle...

 

[wrcsixeight]

Just a little correction needed.
The external regulator "sees" a lower voltage and increases in turn the alternator voltage.


The increased alternator voltage does never reach any circuit of the vehicle.
That's plain and simple the big mystery about diode isolators.

.

I'm not seeing how the 15.2v is limited to only the feed for the isolator. If the alternator is feeding 15.2v because it has been manipulated, then everything will see the 15.2, at least before the expected voltage drop along each individual stock vehicular circuit. What am I missing here?

----
The manual switch introduces an issue. If the Switch is turned OFF, with the engine running, then the alternator will likely fail. Some manual switches have Alternator Field Disconnects, so that if the switch is turned off, the field wires to the alternator are also turned off saving it from a load dump situation.

I am not familiar with Ford and am not sure if the AFD would save the alternator from a load dump situation if the manual battery switch was turned to off with the engine running.

Also with the manual switch, it can be a PITA to get out of the driver's seat to combine the batteries. I generally do not want the battery powering my fridge contributing to starter current. So Before starting, I make sure they are on separate circuits, start the engine, then move the switch to both, or perhaps to only the depleted battery. It is nice having a voltmeter wired to each battery.

You can of course wire/install the manual switch so that it can be reached from the driver's seat. I use the Studs on the battery switch to distribute power too, like from the combined feed to the Aux fuse block, or to the inverter.

I use the Blueseas 6007 series mini battery switches. They seem very well designed and fabricated. Much better than the Guest switch I used for the previous 10 years. I have one switch to control starter/alternator current, one for all Aux loads, and one for the solar. Of course if any of these 3 switches is turned to both, the positions on the other 2 switches are negated.

http://www.amazon.com/Blue-Sea-Syst...6656&sr=8-5&keywords=blue+seas+battery+switch.

I present these manual switches as an option, not necessarily a recommendation.

 

[DiploStrat]

I'm not seeing how the 15.2v is limited to only the feed for the isolator. If the alternator is feeding 15.2v because it has been manipulated, then everything will see the 15.2, at least before the expected voltage drop along each individual stock vehicular circuit. What am I missing here?

The only lead from the alternator goes straight to the isolator. All loads are connected on the other side of the diode. The Weasel is correct; none of the loads will see the increased voltage.

A diode can be made to work if you boost the voltage before the diode or, as is done with the Sterling A2B, you install a second voltage regulator (and amplifier) after the diode.

I have two gripes with diode based systems:

-- Assuming that your starter and camper batteries are of different sizes and discharge at different rates, one of the two batteries is going to be undercharged or overcharged. This is because the diode will allow current to flow in only one direction, from the alternator to the batteries and the alternator is going to put the same current to each of the battery terminals.

-- Most modern RV's have a charge source on each side of the isolator, typically a solar kit and shore power attached directly to the camper batteries. If you use a diode isolator (or a key controlled relay) between your batteries, they will not see the benefit of this second charge source.

"Smart" or automatic relays offer the advantage of combining the batteries whenever there is a charge (typically the presence of 13.2v or more) at either side and separating the batteries when either side drops to 12.7v or so. This is very handy for a vehicle that has to be parked between trips as it assures that the starter batteries are well tended.

It is essential, however, that the cable connecting the starter and camper battery bank be large enough; I use a pair of 1/0 and I might be persuaded to go to a pair of 2/0.

As with all of these things, there are advantages to each approach, diode isolator, relay, dedicated alternator/regulator, secondary regulator, and, at the same time, there are disadvantages. But while I have preferences and can explain them, a good installation is more important that the specific approach you take. The number of vehicles with nightmare systems, for example, 13v alternator feeding an uncompensated diode isolator, connected with 6 AWG cable is really amazing, or, if you prefer, disappointing. I know of one high end vehicle, costing way more than $250k, that had almost exactly that system. Needless to say, he was using his genset a lot. :Wow1: A few changes and genset use dropped to once a fortnight or so.

 

[wrcsixeight]

Ok, thanks. I thought the diode isolators went between the two batteries, not in between the alternator and both batteries.
I think in many setups, that tapping the voltage regulator and moving the stock vehicle loads to go through the isolator increases the circuit lengths and adds complexity.

I wonder what percentage of amperage is turn into heat for that large heatsink to transfer to the air, and how much harder the alternator has to work to produce 15.2 vs the 14.5.

 

[DiploStrat]

If you can't stand the heat ...

I wonder what percentage of amperage is turn into heat for that large heatsink to transfer to the air, ...

I don't know the percentage, but I do know that Sterling sizes their A2B based on the size of the diodes and the ability to shed the heat. That is, the 400A model has much bigger heat sinks and at least as many fans, so the loss is measurable.

 

[4RunAmok]

Now I have a good laugh about the man who starts every second post with: "I do this for a living!"

Instead of telling about people being odd, you should be able to give a brief decription of Bbassos problem, right?

You can't?

Ok, I will do so. As you know, as an "I do this for living" an diode isolator must BLAH BLAH BLAH:

You want to know why I didn't address his issue with the diode isolator? Because I don't don't believe the diode isolator is worth keeping.

My advise through all of this was to remove the wires from it's terminals, remove it from it's mounting, and throw the stupid diode isolator into the trash where it belongs.

I honestly don't care if you think the diode isolator is the greatest thing since the wheel. We don't use them in my industry because they're pieces of junk.

And I don't need criticism from someone such as yourself. You don't like that I dislike diode isolators so you think it's okay to belittle me? You can't say that my advise is wrong, because it isn't. My method works, your method might work. NOT ONCE did I ever belittle your knowledge or character, as much as we disagree on the subject. I've spent a number of years learning what I know, I get paid for doing what I know. And I come on here and offer my advise free of charge, in the hopes that someone finds it useful. You don't like my advise? KEEP IT TO YOURSELF. Others will either find it useful or ignore it.

 

[4x4junkie]

-- Assuming that your starter and camper batteries are of different sizes and discharge at different rates, one of the two batteries is going to be undercharged or overcharged. This is because the diode will allow current to flow in only one direction, from the alternator to the batteries and the alternator is going to put the same current to each of the battery terminals.

Battery overcharge can't happen unless the alternator puts out too much voltage (15.2 - 0.7 (diode) = 14.5V = proper absorption charge).

What may happen though is the more-discharged battery will "steal" all of the current that would otherwise go to the lesser-discharged battery. As it's voltage rises up to that of the lesser-discharged battery, they will then start to share more-equal amounts of current. Given enough time, neither battery will be left undercharged.

I'm on the non-diode side of the fence here also. Compensated for or not, the voltage drop still add further inefficiency to the system (all that heat wasted in the heat-sink could instead be going into your batteries).

 

[DiploStrat]

You probably understand more than I do. My only experience with a diode isolator was decades ago, long before anyone understood voltage drop. In my case, the camper battery had next to no load and ran dry quickly.

My statement was based on the inability of the alternator/regulator system to sense both legs of the diode bridge and this this guru: http://www.smartgauge.co.uk/diodes.html

In any case, although the no-moving-parts aspect of a diode isolator appeals, I don't like the heat loss or the inability of the truck batteries to benefit from shore power or solar charge.

 

[Bbasso]

Aside from the manual labor of turning the switch to another setting is there any really bad issues/ problems with a manual switch like the blueseas?
I need to buy and get something hooked up and running asap.