120v to battery to truck

Please forgive me as this may be a dumb question but I have a 1990 Kit Road Ranger.  I have currently one battery on it and had it hooked up to 120v for a weekend in front of my house and the battery never really charged back over 3/4.  Upon unplugging and taking it to storage I realized two things that may have effected that;

1)  I never unhooked the trailer (power, 5 wauy plug) from the pickup
2)  The frig was running all weekend.

Guess I'm really just trying to figure out if you should unplug from the pickup one on 120v power from outside source and if that vintage of a TT slowly recharges the batt like a trickle charger does?

Even a trickle charger should have charged it in that much time. It sounds as though either your battery is dying, the charger is dying, or there is corrosion built up around the battery cables not allowing the full charge to get to the battery. Having the refer on shouldn't make that much difference.

Several possible issues.. Sarge covered one of them (Bad battery) also how are you determining the battery State of Charge?  Hydrometer, Voltmeter, Display panel inside RV?

Next, you said you ran 120 volt to the battery.. I'll bet you did not because to a 120 volt line a 12  volt battery would be indistinguishable from a direct short.

You ran it to a converter or charger?  What make and model of converter (If you plugged in the entire trailer) or charger (If you used a portable charger) what are it's specs and what size battery do you have "A single battery" I have a 12 volt AGM lead acid battery in the next room that is not even 20 amp hours... I also used to have a pair of 'em that sucked up 130 amp hours.. And I've seen some that suck up twice that.. And flooded wet cells in the "You don't want to know" class.. (I'm fairly sure you do not have an electric fork lift battery).

This is all important to figuring out the problem.

Craig74 said:

Please forgive me as this may be a dumb question but ...

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There is no such thing as a dumb question. The whole point of a forum is to ask questions and to get answers. If you don't know the answer to this question you can bet there are plenty of other people reading this forum that want to know the answer too.

What I mean is a ran an extension cord from the house to the RV for the entire weekend.  The Battery looks BRAND NEW I mean it is super clean and I know the connections are clean as they are all new.  I just figured that because I left the trailer plugged into the pickup that may have been a problem?  Its my understanding that the RV has a built in charger but I'm not 100% on that...

Ok, we now have clairfied the 120 volt to battery to mean 120 volt to RV.

What make and model converter do you have... Some of them charge very very very very slowly.  Others much faster

IF a single door covers both fuses and breakers,,, What is the make and model on that door.

I wish I was more help (I don't know that there is a converter in this thing).  All I did was pull out the long black cord from the RV, (3 prong) and using an RV adapter I got from Lowes plugged the RV into my extension cord coming from the house.  There was only one battery hooked up to the RV and again, it is absolutely spotless as is the new box and strap it came in from dealer at purchase time. 

There SHOULD be a converter... The problem is we do not know where it is.. However there are two clues we can use to track it down.

1: Somewhere inside, or outside, (Usually inside) is a door behind which there are circuit breakers... IF there are also fuses behind this same door (Note if the box is inside a cabinet I'm talking about the last door you open (The box itself) then there is a fairly good chance the converter is behind the fuses/breakers..> The make and model info should be on the door.

IF the fuses are behind one door, and the breakers another, as it is on my rig, two different boxes.  Then the converter can be anywhere.. Listen for the fan, look for a blinking light, and otherwise search for anything making noise.  May be inside, under or behind, May be in a basement compartment.

Have the battery load tested.  Even a brand new "off the showroom floor" battery can have a defect.  A used one, regardless of how new it looks, could be nothing but a door stop.  If the battery checks out good, then it's time to figure out why it's not charging while installed and on shore power.  Many variables.

As mentioned before, info on the converter might help with getting some answers.  If the battery and all the connections prove good, your next focus is going to be the converter anyhow.   

Craig74 said:

All I did was pull out the long black cord from the RV, (3 prong) and using an RV adapter I got from Lowes plugged the RV into my extension cord coming from the house.

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FWIW-I will never adapt down to 110 volt from my RV cord again. It was a $600 mistake as the extension cord and the power supply burned up. I was lucky it wasn't any worse. Just my opinion.

John From Detroit said:

There SHOULD be a converter...

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It's easy to check and see if you have a converter.  Unplug the trailer from your truck.  Disconnect your negative (ground) battery cable.  Plug your trailer power cord into an outlet.  Use a 12V test light on the battery cables.  If it lights up, you have a converter.  If it doesn't, either you don't or it's not working.  (You could also simply try turning on a light in the trailer instead of using the 12V test light, but I don't know enough about your rig to be sure your 12V power from a converter doesn't go through the battery circuit before it becomes available to the interior lights.)

If you don't have a 12V test light, they're cheap and readily available at auto parts stores and they're awfully handy for a variety of diagnostics.  Also cheap - and handy - are volt-ohm meters.  With one of those, you could tell how much voltage the converter is sending to your battery (again, with the battery ground disconnected, but the trailer plugged in).

I wouldn't suggest leaving the trailer plugged in with the cable disconnected for any longer than you need to do the test(s).  I don't know much about converters, but I'm under the impression some prefer to be connected to the battery when they're outputting power.

One other thought.  You mentioned the fridge was left running, but didn't say on what power mode.  If it happened to be running on 12V, it seems at least possible to me that pulled enough power from the converter's output to significantly reduce your battery charge rate.

How big an extension cord and how long? Any significant current draw will require  you use at least a 12 ga. extension to ensure proper voltage at the converter. Probably not your problem, but good to know. Also, did you check to make sure you didn't blow the house breaker?

Ernie

Really great info everyone THANKS!  To add, I did not blow the house breaker and yes, the extension cord coming from the house was not a good one so maybe I did get lucky    The fridge was turned to electricity vs propane.  There is one breaker panel inside that I have found and it has the fuses as well right there.

Low voltage coming from a long extension cord won't bother a modern switching supply converter - generally they're good on anything from 95 - 100 volts on up.

But a 1990 Kit probably has a transformer based linear converter. These are sensitve to low voltage since their output voltage is directly proportional to the voltage going into them.

With a long extension cord and the load of the refrigerator operating in electric mode you probably had low voltage all weekend, so the converter's output voltage stayed low and couldn't fully charge the battery.

Next time let the fridge run on propane - it uses very little - and see if the higher AC voltage keeps the battery charged.

This time around (120v) coming from house to TT I am using a new 100' 12gauge extension cord to the TT and my fridgerator is shut off.  I only have on deep cycle battery on my TT.

Craig74 said:

...1)  I never unhooked the trailer (power, 5 wauy plug) from the pickup

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I would unplug from the tow vehicle. If the charge/hot wire is actually connected, they are often not a heavy enough wire for the length of the run to provide a very good charge, but will keep drawing current. Depending on how the tow vehicle is wired, it may or may not have been trying to charge the tow vehicle battery as well as the RV battery.

If the converter in the trailer is the original 24 year old one, I doubt that it is a multi-stage charger so is not putting out the high initial charge voltage of the more modern ones. If you have a good stand alone multi-stage charger, I would disconnect the battery and use that charger when you do not need the RV plugged in for other reasons. There are generally phantom loads that will drain the battery of the RV even when you think everything is off so installing a battery disconnect or disconnecting the battery when not plugged in during storage will help prolong battery life.

I agree that a 20+ year old rig likely has something like a Magtenek 6300 which is the converter I put in absolutly LAST place on the list of products to buy or 1st on the avoid list.. An upgrade to a Progressive Dynamics 9200 (Try to match the last two digits) is highly indicated.

With one battery, I seriously doubt it is a deep cycle as true deep cycle 12 volt are out there,,,, Just rare.

IF you can find room for it (if the battery try is large enough) use a golf car battery (GC-12) or two six volt golf car batteries.

These,, really are deep cycle

most 12 volt "Deep Cycle" are really Marine/Deep Cycle and frankly... Not that good.

What is the practical difference.

Starting batteries. if you run them down too far... (Say 10 volts) replacement is generally indicated
Marine/Deep Cycle.. May recover from an "opps" of that nature
DEEP CYCLE.. Well, my Interstates lasted over 8 1/2 years, nearly 9 (Replaced them last monday, 9 years,, Well considering the time they were in the house in the factory, likely has passed already, took delivery in May of 2005)

They hit 10 volts more times than I care to admit.. And recovered all but the last time (Actually when the cell shorted it was fully charged near as I can tell)  Never had a marine or starting battery do that well.

Ok this might sound stupid but did you look to see if the cells are dry? I know you said it is a new battery but sometimes these things set for awhile and sometimes they ship dry to save on freight. That would be the first thing I would check. My husband and father both worked for auto part sales and dry new batteries are very common.

This time around it was much better as i did the following this time that I did not do last time (yes I have one, TRUE Deep cycle Bart on)

1)  Unplugged TT from tow vehicle
2)  12 gauge 120v extension cord vs other, smaller

I'm still really confused on the converter (I don't even know where the hell its at)?  As this is my first TT and given its age (amazing shape) I dont know how long I will keep it so Im not really putting more $ into it....

Your converter is directly behind the electrical breakers and fuses.  The door you open to see the fuses and breakers is the door to a box that contains the converter as well.

Your getting there!  As for what battery to use.  Consider how much you plan to use the camper with out 120VAC service.  Lots of things run on 12vdc in your camper,  Lights, heater blower, water pump, fridge controls for propane, and some others im sure.  If you only plan to use it while on 120VAC most of the time.  A single battery will likely be adequate.  If you plan to "Dry Camp" without 120VAC,  Get all the batteries you can afford and carry, Then convert lights to LED and search for other ways to conserve your 12vdc capacity.

Hang in there.  Its not rocket science,  Its just different than what you are used to.