I installed a direct line from my converter/charger to my house batteries to avoid the voltage drop accross my old silicon diode isolator. The house power disconnect doesn't work now, so I believe I am now feeding the house current back through the converter/charger (55 amp Intelli Power with Charge Wizard). I think I need a Schottky diode in line from the converter/charger to the battery to prevent this back flow.

Does anyone have any thoughts on this? Where can I get a Schottky diode suitable for this application?

I installed the same converter (60 A) with Charge Wizard on my SOB, and it was (almost) fairly straightforward.

You wouldn't be backfeeding the house battery through the Intellipower.

One thing first comes to mind:

The power to the disconnect relay (operated by the house power disconnect switch) is bypassed.

If the Regency's system is like my Breakaway, the isolator is powered by the engine alternator, not the converter, and it charges both house and engine (chassis) batteries. The converter doesn't charge the chassis battery -there's no isolator in the converter's circuit.

I suspect if you restore the isolator to the circuit (as originally wired), the disconnect will work properly, because in rewiring, you've bypassed the disconnect circuit.

quote:

Originally posted by Bill G:
Where can I get a Schottky diode suitable for this application?

Try E Bay

Sure power used to sell them. They have about half the voltage drop of silicon diodes.

Try Ample Power, too.

I seem to have lost my file on that.

Rusty,

I never disconnected the original isolator or rewired anything in the system. I simply connected the converter/charger to the house batteries directly. This was done to avoid the voltage drop through the isolator.

This is why I believe the house batteries are backfeeding through the converter charger. The output from the converter/charger feeds both the house when plugged in as well as charges the batteries.

It seems logical that a schottky diode in the battery line should solve this problem. Plus, as billh said, there is a much lower voltage drop across a schottky diode.

Bill G

Do you have two isolators (one for the alternator, another for the converter)? A single isolator is tied to the alternator.

Otherwise (one isolator), the converter would have connected directly to the coach batteries, usually through the power panel. Bypassing the power panel may also have bypassed the house cutoff switch.

What mods did you do to connect the converter directly to the coach batteries?

Backfeed is not an issue, as the converter is designed to be connected to the batteries all the time.

If there are one, or two, isolators, replacing either or both with a Schottky isolator will lessen voltage drop across the isolator, and increase efficiency, but the little suckers are very expensive.

Anyway, here's a site that may be useful. It wasn't for me because of the way my SOB was wired, but the only thing I had to do was install a new buss wire because the power panel was split due to having a two-way converter as OEM.

Rusty,

The original converter was replaced before I purchased the Barth. The new one was only wired to the 12 volt breaker panel with no connection to the batteries unless there was a feed to the isolator from the 12 volt breaker panel. I am not sure of this.

Since the new converter was an Intelli-Power unit, I ordered a Charge Wizard to connect to the unit to better control the charging. When I went to connect the Charge Wizard, I discovered a #2 Ga wire near the converter charger that ran directly to the the positive terminal of the house battery but was not connected to anything in the electrical compartment. Because of its location, I figured that it was connected to the old converter/charger, but because of the large size of the wire, it could not be connected to the new converter/charger (Intelli-Power has a capacity of up to #6 ga wire only with a single positive output) so it was simply left unconnected. Also, maybe the old converter/charger had seperate connections for the house converter feed and the charger feed, thus isolating the batteries from the converter. I spliced this together with the positive output from the converter/charger to create a feed to the 12 volt breaker panel and for battery charging that bypassed the isolator to avoid the voltage drop.

This also created a direct feed from the house batteries to the 12 volt breaker panel (therefor bypassing the 12 volt dissconnect as well).

I believe that if I place a single schottky diode in the line to the house batteries, I can prevent this bypass from occurring and gain controll of the house power dissconnect.

My other converter/charger connects only to the start batteries and is used soley as a battery charger (with a Charge Wizard as well).

What is your thinking on this?

Bill G

Ps. In the link you included in your earlier post, the mangatech converter/charger had two positive outputs, one for the breaker panel and a seperate one for battery charging. This may have been the case with my previous unit as well. The person who wrote that post also connected both of those wires together for connection to the Intelli-Power unit. This is basically what I did as well.

Thanks, Bill, I'm beginning to get a picture, and I think I'm getting a handle on the issue.

I need you to confirm two things:

1. Is there a second isolator for the house batteries, and

2. If you unplug the coach from 120 VAC, does the disconnect switch work?

BTW, The older 2-way (2-output) converters did have two +12 V wires - as you suspected, one for the house 12 V power and another for the battery. The battery charger itself was a separate section in the converter, and usually of much lower capacity than the converter's rating. My old converter was rated at 60 A, but the charger itself was only 15 A.

The converter had a relay in it that would physically switch 12 V power to the house power panel. When 120 VAC was plugged in, the relay would switch the house 12 V circuits to the converter output (and disconnect the house battery), and separately, the charger would charge the battery. When 120 VAC was disconnected, the relay would drop out and connect the batteries to the house 12 V.

Now, the Intellipower (single output) uses a different technique. It is connected directly to the battery. The batteries are connected to the house 12 V panel through a separate circuit which includes the disconnect relay.

Rusty,

quote:

1. Is there a second isolator for the house batteries?

- No, only a single isolator with one input and two outputs, isolating two banks of batteires.

2. If you unplug the coach from 120 VAC, does the disconnect switch work?

- The disconnect nolonger functions when the coach is not plugged in.

My Intelli-Power is wired directly to the breaker panel and to the house batteries. My house batteries are four six volt Interstate Workaholics.

The overall 12 volt system on my coach is fairly complex. This is my first experience working on a system this complex, so your assistance is certainly appreciated.

By the way, I've been searching the Internet for a single leg Schottky Diode to fit my needs and have yet to find one.

Bill G

Thanks for the additional info. If there's just one isolator, then it's powered off the alternator, and has nothing to do with the issues at hand.

Feeding the batteries directly from the converter is also the way the Intellitec should be wired.

The question is, what's that old #2 wire for? Is it the old wire from the old converter charging circuit, or is it the old wire from the battery/disconnect switch. We'll find out!

Remember that the old converter was a dual output.

The wiring would be like this:

1. +12V Main Converter output: Direct to 12 V power panel.

2. +12V Charger output: Direct to battery

3. +12V Battery output (a separate wire): Through the disconnect switch, then to the 12 V power panel.

The disconnect switch was bypassed when the converter supplied 12V power, and only operated when the converter relay had switched to the battery power circuit.

With the Intellipower, a one-output converter, 12V is supplied to the battery, and the battery powers the 12V power panel at all times.

Here's the next (hopefully final) step. Disconnect that splice you made with the old #2 wire. If the disconnect works, tape up the #2 and you're done. I don't think it runs directly to the battery.

Here's why: I suspect that your wiring is like this -

One wire comes from the battery to the hot side of the disconnect relay. TWO wires come off the switched side - one going to the 12V power panel, and the other that #2 wire you found (which would have gone to the power section of the old converter, and have powered the power panel through this terminal). By splicing it in tothe Intellitec's +12V, that made the switched side of the disconnect relay hot all the time, and the relay, although in actuality it's working, is bypassed.

The good news is that if disconnecting that #2 wire restores the disconnect function, it's surplus. The disconnect switch will now operate as before - when the converter has 120VAC, it's bypassed. When the battery supplies the power panel, the disconnect is in the circuit and will work.

I hope this works...

One more thing - if my suspicions are correct about how this thing is wired, the converter will charge the house batteries only when the diconnect switch is CONNECTED.

Rusty,

The disconnect is really out of the loop. Since the Intelli-Power is directly connected to the batteries, the disconnect when on or off is not a factor.

What I need is a way to disconnect the feed from the charger to the batteries when the coach is not plugged in. I figured a schottkey diode in line would work, but I also think a relay that is 120 volt activated would also do the job. I only need for the charge circuit to work when I'm plugged in or running the genny. When I'm boondocking or traveling the charger will not be working anyway.

Even a manual disconnect should do the job, however; since I plan to add a solar panel, the shottkey diode is what I would really prefer to use. I just can't find one.

I'm still searching for a way to effectively break to flow of current from the battery back to the breaker panel.

Bill G

I still have my SOB, so if I get a chance (busy weekend, as I have to get ready to go to a funeral in MO next week) today, I'll go see how the Intellitec prevents backfeed from the batteries, because it's designed to be connected all the time. It may be a relay, or diodes, but battery drain isn't a problem.

It may be most practical just to put a manual cutoff at the battery, or as you suggest, a relay that would open when 120V is disconnected - but that may be unnecessary. A relay would be preferable to a Schottky, as there's no loss across a relay.

Rusty,

Since there is only one output on the Intellitech, back feed can't be controlled. The feed to the breaker panel and batteries is tied together as it leaves the converter/charger. This is why I need the Schottky diode in the battery leg.

If anyone knows of a source for an in-line Schottkey diode, please let me know.

Bill G

Been away (still am in MO) to my stepfather's funeral.

Anyway, the Schottky is redundant with the diodes in the Intellitec, which is designed to be constantly connected without draining the battery. A Schottky would lower the efficiency and cost money unnecessarily.

A cutout switch would provide a certain benefit (wired to cut out the battery from the Intellitec and the house 12V circuits).

Rusty,

Your advice is sound, I have already started to look for two simple disconnect switches.

Bill G