DC Converter

ALMcKinney · 06-07-2011, 08:57 PM

Hi All,

My Parrallax 7155 DC converter was blown during a power surge and I replaced it. I hooked up the AC power to test and noticed that the unit fans started to run after a few minutes and seem to run contionously till the batteries started to boil. I disconnnected the AC and shut the breaker off on the converter as I was worried.

Is the converter supposed to boil the batteries?

Thanks,
Al

**Herk7769** · 06-07-2011, 08:57 PM

No Al, something is wrong.

**Herk7769** · 06-07-2011, 10:20 PM

I noted that you did the replacement. I would first remove power and check my work. My first suspicion is a mis-wired connection that is shorting out the battery.

ALMcKinney · 06-08-2011, 10:03 AM

Quote:

Originally Posted by herk7769

I noted that you did the replacement. I would first remove power and check my work. My first suspicion is a mis-wired connection that is shorting out the battery.

Hi,
I double checked my wiring to the converter and even took pictures before disconnecting and compared everything is hooked up as it was originally. There's no 12 Vdc fuses blown and the fuse between the battery and converter is ok.

Thanks,
Al

NorminN.B. · 06-08-2011, 10:12 AM

Did you check the voltage going to the batteries. Maybe you have a bad regulater?

ALMcKinney · 06-08-2011, 10:15 AM

Quote:

Originally Posted by NorminN.B.

Did you check the voltage going to the batteries. Maybe you have a bad regulater?

Isn't the regulator part of the converter?

Thanks
Al

NorminN.B. · 06-08-2011, 10:20 AM

I would check the voltage going to the batteries first. Should be around 14.5 volts. If it is too high, the regulater on the converter is bad, making the battery boil. Hope this helps.

jimh · 06-08-2011, 10:24 AM

what voltage do u show on the battery with all (shore power) disconnected. what voltage do u show on the bat with shore power on?
my old standby response is to check and see if the battery is bad.

ALMcKinney · 06-08-2011, 12:09 PM

Quote:

Originally Posted by jimh

what voltage do u show on the battery with all (shore power) disconnected. what voltage do u show on the bat with shore power on?
my old standby response is to check and see if the battery is bad.

Hi,
New deep cycle I had it checked as that was my first thought 12.23 Vdc

**Herk7769** · 06-08-2011, 01:38 PM

There should be a troubleshooting guide in your converter manual.
I would start there and a call to the Tech Support line for your converter.

ALMcKinney · 06-08-2011, 02:27 PM

Quote:

Originally Posted by herk7769

There should be a troubleshooting guide in your converter manual.
I would start there and a call to the Tech Support line for your converter.

I think I will.

Thanks,
Al

ALMcKinney · 06-08-2011, 02:30 PM

Quote:

Originally Posted by jimh

what voltage do u show on the battery with all (shore power) disconnected. what voltage do u show on the bat with shore power on?
my old standby response is to check and see if the battery is bad.

Quick question what would happen if the battery neg was disconnected with shore power hooked up? Would it have any ill effects on any 12 Vdc circuits?

I thought I read not to do that somewhere on the forum i.e. someone did and they fried thier stereo or something that was 12 Vdc.

Al

**Herk7769** · 06-08-2011, 03:25 PM

Quote:

Originally Posted by ALMcKinney

Quick question what would happen if the battery neg was disconnected with shore power hooked up? Would it have any ill effects on any 12 Vdc circuits?

I thought I read not to do that somewhere on the forum i.e. someone did and they fried their stereo or something that was 12 Vdc.

Al

Al, the battery is the primary 12VDC source when the converter is powered or not. The converter, if powered, will kick in when the battery voltage starts to drop due to load (like opening a slide). It will shut off after the battery is recharged.

The converter is capable of providing 55 amps at 12 VDC total at peak production. If the battery is completely disconnected the converter will "read" zero volts from the battery and stay on constantly providing DC power to all items requiring DC.

ALMcKinney · 06-08-2011, 03:36 PM

Quote:

Originally Posted by herk7769

Al, the battery is the primary 12VDC source when the converter is powered or not. The converter, if powered, will kick in when the battery voltage starts to drop due to load (like opening a slide). It will shut off after the battery is recharged.

The converter is capable of providing 55 amps at 12 VDC total at peak production. If the battery is completely disconnected the converter will "read" zero volts from the battery and stay on constantly providing DC power to all items requiring DC.

Sir (I noticed the rank),

Thanks,

But if the converter's output voltage was not regulated it could damage a 12 volt circuit then if the battery was removed from the circuit.

Sorry for all the questions trying to educate myself.

Kind regards,

Al (US ARMY Veteran)

**Herk7769** · 06-08-2011, 03:53 PM

Quote:

Originally Posted by ALMcKinney

Sir (I noticed the rank),

Thanks,

But if the converter's output voltage was not regulated it could damage a 12 volt circuit then if the battery was removed from the circuit.

Sorry for all the questions trying to educate myself.

Kind regards,

Al (US ARMY Veteran)

Sorry Al, but I am a PFC now.

I see what you are getting at. If the converter is "running away" then the battery would act like a shock absorber and that would certainly boil it dry. Get on the horn to Tech Support ASAP.

jimh · 06-08-2011, 05:10 PM

if the converter is working properly, i wouldn't think that disconnecting the bat would damage anything. the older trailers useto power the trailer without the bat. my understanding is that the bat is always in now. my trailer has a disconnect switch that separates the converter from the bat. with it off, the bat is out of the system but the rest of the trailer will still be powered by the converter.
the reason i ask abt the voltage on the bat with the shore power off for a few minutes was to determine if u had a bad cell. you should read 12.6 but i wouldn't quibble abt a couple tenths of a volt.
the next question was going to be if the lights in the trailer work with the shore power disconnected. if the bat voltage remained good and the lights would not burn, i was going to suggest looking for a battery disconnect that may have the DC shut off to the trailer.
even if the converter has problems, with a good bat, and the shore power disconnected, u should still have lights and the frig should work on propane.
on my trailer, the bat disconnect separates the battery from the converter. (everything from the DC fuse panel will still get power from the converter). the slide outs hydrolics and the vehicle remain connected to the bat.
i'd really like to know what the battery voltage is when the shore power is on. if it is approaching 14.5 or 15 volts, i would really be concerned.

jimh · 06-08-2011, 06:08 PM

One other question. How long does it take to boil the water out? A day, a month?

ALMcKinney · 06-08-2011, 08:37 PM

Quote:

Originally Posted by jimh

One other question. How long does it take to boil the water out? A day, a month?

The rate mine was boiling I would say less than 24 hours in overcharge. Average use I would say check them every 90 days and add distilled water if needed,

Al

jimh · 06-08-2011, 11:38 PM

that's too much. i was hoping it wasn't that serious.
it may be nice to play with it but that sounds like the manufacture would be ur best bet.

the only other thing i would suggest would be to double check ur wiring. make sure they didn't change the wiring locations from the original and the replacement. not very clear (to me)...watch the labels.

ALMcKinney · 06-10-2011, 08:37 PM

Quote:

Originally Posted by jimh

that's too much. i was hoping it wasn't that serious.
it may be nice to play with it but that sounds like the manufacture would be ur best bet.

the only other thing i would suggest would be to double check ur wiring. make sure they didn't change the wiring locations from the original and the replacement. not very clear (to me)...watch the labels.

Ok put a new converter in and it seems to be working no boiling battery.

I checked the voltage and I have 13.4 volts going to the battery and I also have the same amount across my 12 Vdc circuits is this normal?

Al

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