Scamp battery discharging when stopped and still connected to tow vehicle....

[DogHaus]

Hi, this happened to me last weekend: Traveled 2.5 hours to my destination towing my 2005 Scamp 13', which has no refrigerator, just an icebox, no air conditioner, no hot water heater. It does have the basic furnace, water pump, fantastic fan. Electric brakes were added last year. Arrived but did not unhitch or disconnect 7 pin power cable between Scamp and TV for 7 hours. When I did unhitch I noticed that the Scamp's battery seemed low and sure enough, it didn't have enough juice to power the furnace fan overnight
Next morning while backing into position to hitch up, noticed that the car seemed like it was going to stall on me.
Trip home was uneventful. Towing charged the Scamp battery right back up. Unhitched and put everything away. I store the Scamp without plugging in to a/c power. This morning the Scamp battery remains fully charged (measured with voltmeter) and the vehicle seems fine too.
Battery water level on Scamp is good.
Any thoughts about this? Is it common to have a battery drain while the TV is not running and the Scamp's cable is attached?
I've had the Scamp for 5 years now and usually I do disconnect the cable when I am stopped for any length of time, so I'm suspicious that this may have happened to me once before and I don't remember it.

[Bob Miller]

First question is if you use 12 VDC or an Inverter and 120 VAC to power the refrigerator?


The next possibility is that you have either a TV or coach battery that has about reached the end of it's life and is leaking both down due to internal leakage.


And last, how are you measuring/judging your battery condition?


I just left my Hunter unplugged/unused for 6 weeks and the battery was still at 12.62 volts when I reconnected the Voltminder three days ago.

[boats19]

I haven't had a problem like you describe but I was worried I might...
I installed a 75 Amp blocking diode between the TV battery and 7 pin. That way I am sure the Scamp gets a charge but it's a one way street!

http://www.amazon.com/gp/product/B00...ilpage_o02_s00

[John Linck]

I always unplug when stopped for more than an hour or two. Not sure why, though Doghaus's experience reinforces my thinking. Also I am afraid of draining the TV battery. Gary's blocking diode sounds interesting.

John

[Wayne Collins]

Originally Posted by Doghaus

Hi, this happened to me last weekend: Traveled 2.5 hours to my destination towing my 2005 Scamp 13'. Arrived but did not unhitch or disconnect 7 pin power cable between Scamp and TV for 7 hours. When I did unhitch I noticed that the Scamp's battery seemed low and sure enough, it didn't have enough juice to power the furnace fan overnight
Next morning while backing into position to hitch up, noticed that the car seemed like it was going to stall on me. ..... .

Welcome to the "club" I suppose each one of us has had that experience. Seems you were lucky that you car battery did not go down too.
If you operate the Fridge on 12volts while traveling, it leave it hooked up when the engine is off, it will discharge both batteries.
The idea of a diode between Scamp Batter and 7 pin connector is a good one.
Anyway, I have gotten in the habit of just switching the fridge OFF whenever we stop for lunch, or a WalMart walkabout. If it will be a longer time, start the LP heat on the fridge.

[DogHaus]

hi Bob, I do not have a fridge, just the icebox, no power there.
We measured battery charge with a voltmeter.
Volt blocking diode sounds very good. thanks Gary!

[Radar1]

That sounds strange since you don't have a fridge, which is the normal culprit if you stay hooked to the TV. Other possibilities would be if the heater may have been fully off past the click, or still partially on and running, although that should not have drained the battery overnight in these temperatures. Another possibility is that the tow vehicle had something left on and was sucking the juice out of the Scamp battery once the tow vehicle battery got low.
I'm in the habit of unplugging whenever I stop even though I don't have the power robbing 12 volt fridge, just need to remind myself to plug back in when morning comes, or replace the connector after it gets ground down. :-(

[Bullington]

I wouldn't use a blocking diode on low voltage. It causes the battery to not fully charge sometimes as it requires some voltage to simply push the gate open in the diode. I prefer a system that senses charge voltage and then closes a relay allowing it to flow to the trailer "house" battery. It's a set it and forget it system. No need to unplug from the TV, if it is not sensing charge voltage it is disconnected. Blue Seas makes the one that I use. https://www.bluesea.com/products/761...12_24V_DC_120A

[Bob Miller]

This is how it's been done in motorhomes for more than 50 years and will work just fine on a battery charging line if needed. costs a lot less than $20
http://www.amazon.com/Tekonsha-7000-.../dp/B0002UHVYQ


NOTE: This IS NOT a starter solenoid, they are not designed for constant use and can fail prematurely.

[Joe Romas]

Doghaus

I read in your post YOU DO NOT HAVE A REFRIGERATOR

I think the 2.5 hours you traveled each way was not enough to completely charge your battery completly

I suggest you get a smart charger to charge your battery completely.

On another site there was a thread where a person figured out the voltage drops at each stage from your car's alternator all the way to the trailer battery.

Pure and simple the voltage that reaches the camper's battery is not enough to completely recharge a wet cell battery at the needed 14.1 to 14.8 volts.

Here's a decent
BATTERY CHARGING TUTORIAL

Battery Charging Tutorial | ChargingChargers.com


Joe.

[Carol H]

Is it possible you had somehow left the water pump switch on while you towed it? or perhaps the furnace switch was left on while towing and either or was coming on & off?

[stevebaz]

If you have electric brakes and a breakaway switch I would check those. A pulled breakaway switch would discharge your battery.

[DogHaus]

Hmmm.... those battery charging numbers don't seem to be the same as what I was told.... need to do a little more investigation. I use a digital voltmeter to measure the voltage and it's a marine deep cycle battery. I don't remember hearing anything about Gel. I thought fully charged was just under 12 v?
Breakaway switch appears ok and the camper has been sitting for two days now not plugged in, and the battery seems fully charged from the 2.5 hour drive home. The battery is 4 years old, so maybe should do that test with the little syringe thing with the balls in it.

[Bob Miller]

Yep, the numbers shown in the link, for % charge, are standard values for lead acid batteries.

You might want to check and see what your charging voltage is when the charger is connected to the battery. It's the "difference in potential" (aka Voltage) between charging voltage and battery voltage that causes current flow into the battery when charging.
For example, if your charging voltage is 12.4 volts, you will never get above a 75% charge and even that will take a long time. And keep in mind, there is something called the "surface charge", that will lead to incorrect readings immediately after charging. A "Hydrometer" is what you want to ask for to check specific gravity (Charge State).


If your Scamp has the "American" brand converter, I'd suggest looking into the progressive Dynamics PD-4045 power center to update your electrical system. It has a 3 stage smart charger and will make your battery very happy. I run dual batteries on mine.

[Carol H]

Originally Posted by Doghaus

I thought fully charged was just under 12 v?
.

Nope. If its reading under 12 its actually starting to get well down in discharged. For example at 11.9 its actually only at 40%.

Many here who like to keep a healthy battery on the trailer do not normally run it below 11.75 which is 30%.

[Byron Kinnaman]

I had something this and it turned out to be a worn out battery.

[Mike Magee]

Based on your conception of full-charge voltage, I'm going to agree with Byron. Your battery probably has not received (or taken) a full charge for a long time. My 12V battery in fairly good condition, fully charged and resting awhile after charge completion, usually read about 12.85V. 12.1V is considered about 50% charged. If yours stays under 12V... it's time to play "Taps" over that battery.

[DogHaus]

Thanks everyone. I plugged into the inverter overnight and unplugged it this morning. Will investigate with multimeter tonight and see what I want to do. I have two more Scampouts left this season and it's going to be below freezing temps, so I anticipate buying a new battery .

[Joe Romas]

Doghaus
I had my Casita plugged in yesterday while I did some cleaning. It's has a simple older Parallax 6325 converter. After finishing my cleaning I unplugged the shore power and this morning the battery voltage was 13.0 volts and the overnight low temperature was 36 so the surface charge should have been gone.

I agree your battery is toast and if you do a lot of boon dock camping I would NOT buy a new fancy converter and instead buy a fancy battery charger that you could also use on your TV or any thing else with a 12volt storage battery.

Joe

[Bob Miller]

Originally Posted by Doghaus

Thanks everyone. I plugged into the inverter overnight and unplugged it this morning. Will investigate with multimeter tonight and see what I want to do. I have two more Scampouts left this season and it's going to be below freezing temps, so I anticipate buying a new battery .

I think you meant to say Converter, the big question is what was the charging voltage at the battery when it was turned ON. If that's much below 13.5 volts you will never get a full charge