AMP Draw Issues

[bankerae]

Good morning Folks! I am hoping someone can point me in the right direction...

We have a 2005 Keystone Outback 26RS travel trailer and did our first dry camping last week. When the heat quit about 1:00am I knew something was not right 🙂

I just did an amp draw test and here is what I came up with:

Using a VOM meter set on the 10amp setting

with the power cord unlplugged and testing through the negative battery cable with everything turned on I was getting a .65 amp draw reading... after taking each fuse out one at a time here is what I found:

The 15amp fuse tied to the LP leak detector (may be powering other items too?) was pulling .08 amp

The 15amp fuse for the fridge (the fridge was turned off, however when I would put the fuse back in it would let out a loud beep) was drawing .54

When I tookt he fuse out for the fridge and the LP leak detector I was left with .03 amp draw

So there's the data, just not sure what it all means!

Thank you in advance for your help!

[red31]

Sam Spade wrote:


I'm done.

thank you. try keeping your word.

[harold1946]

Sam Spade wrote:

mike-s wrote:

Sam Spade wrote:
The truth is nowhere near to what you and the video is claiming.

Dispute documented facts all you want - the truth is plain to see.

That video does NOT qualify as a "documented fact" and therefore you have provided NONE.

Go to batteryuniversity.com and study some more.
To get an accurate voltage reading the battery should be allowed to rest at least 6 hours, (preferably 12 hours) to gain any accuracy as to the state of charge. It should read 12.73. at 100 percent charge.

[Sam_Spade]

mike-s wrote:

Sam Spade wrote:
The truth is nowhere near to what you and the video is claiming.

Dispute documented facts all you want - the truth is plain to see.

That video does NOT qualify as a "documented fact" and therefore you have provided NONE.

[mike-s]

Sam Spade wrote:
The truth is nowhere near to what you and the video is claiming.

Dispute documented facts all you want - the truth is plain to see.

[Sam_Spade]

mike-s wrote:
Finally, working at Radio Shack for 50 years doesn't make you an expert.

How does AT&T and Bell Labs strike you, Mike ???

And finally......AGM batteries don't gas in the conventional sense.

And even a conventional battery won't gas enough to be significant given the parameters in the video.

IF one has conventional batteries, you should ALWAYS check the electrolyte level about every 90 days, in normal use or on a maintenance charger, even an automatic one.

If you really cared about his, Mike, you would do some serious research about what is likely to happen to large batteries if they are subject to ~15 volts/ .75 amps for a couple of hours a day.

The truth is nowhere near to what you and the video is claiming.

[mike-s]

Sam Spade wrote:

mike-s wrote:
Feel free to boil your own batteries while in storage. Other than that, you'd do well to follow your own advice and avoid spreading bad info.

750 ma for maybe two or 3 hours a day will NOT " boil your battery".
It just will not.

You're arguing against demonstrable facts with your unsupported and ill-informed opinion. You're simply wrong, but keep digging that hole.

Sure, 15 V for 2-3 hours for ONE DAY may not damage a battery. But, it will definitely cause gassing. But this is also about leaving the panel connected during "long term storage," and 2-3 hours/day of overcharging over the course of weeks or months with no battery watering certainly can damage batteries.

Providing that bad advice, when the potential damage to hundreds of dollars worth of batteries can be easily taken care of with a <$20 controller (or <$5 voltage regulator) just points to bad intent. You're willing to advise that people put their investment in batteries at risk for the sake of trying to win an argument you've already lost.

Edit: I don't really care whether you accept facts or not. I'm only concerned that someone may follow your bad advice and ruin their batteries, when that's easily and inexpensively avoided. Finally, working at Radio Shack for 50 years doesn't make you an expert.

[Sam_Spade]

mike-s wrote:
Feel free to boil your own batteries while in storage. Other than that, you'd do well to follow your own advice and avoid spreading bad info.

Well that IS THE POINT EXACTLY.

750 ma for maybe two or 3 hours a day will NOT " boil your battery".
It just will not. Not even a tiny little motorcycle battery.

That is not bad information.

Now.....the point trying to be made here is valid for plugin "trickle chargers" that run 24/7 because they may go up as high as 15 volts and stay there......forever.

And further, the example in the video was AGM batteries. If the bank isn't being drawn down enough so that a 750 ma source will hit the point of over charge in less than 4 hours....you probably don't need ANY charging source on a bank with that kind of (non)usage; certainly not every day.

The suggestion of a trickle charger and timer is valid here too.....only the rotation of the earth provides the timer for a solar source.

I've been in the electronics industry for about 50 years and nothing you can say or quote is going to convince me that a 750 ma source is going to damage a battery setup like in the video where any excess charge is spread across that large a plate area and electrolyte volume.

I'm done. Rant on as you please.

[mike-s]

Feel free to boil your own batteries while in storage. Other than that, you'd do well to follow your own advice and avoid spreading bad info.

[Sam_Spade]

mike-s wrote:
A charge controller (or at least a voltage regulator of some sort) is necessary. A 12 W panel can easily overcharge batteries. Video. A 10 W panel isn't significantly different.

This is a perfect example of a self appointed Internet expert spreading false, although not dangerous in this case, information and other people helping him do it.

Although I agree that a simple regulator in the circuit is always a good idea, I do NOT AGREE that what is illustrated in the video constitutes any kind of real problem.

The 15.1 volts illustrated will only be present for about two hours of peak sunlight and the resulting 750 ma is NOT enough to do any damage to any kind of decent battery; especially not the bank of two 6 volters in series.

For about 22 hours a day the charge applied would be less than 15 volts and for something around 14 hours a day it would be near ZERO.
This is hardly anything to get excited about.

[mike-s]

Ham Radio HF Mobile wrote:
connect at least a 10 Watt Silicon solar panel to the coach battery system, and leave the solar panel on the front dash behind the windshield with the motor home facing south so that the solar panel is exposed to sunlight. The 10 Watt solar panel will have right about a 625ma output current during the middle part of the day, and that should be enough for most motor homes to keep the battery charged while in storage, but not be too much to over charge the battery. A small "charge controller" (an alternative energy industry phrase for a special purpose voltage regulator) can be added between the solar panel and the battery to alleviate any concerns about overcharging, but with the size solar panel involved in this case, that is not a serious problem.

A charge controller (or at least a voltage regulator of some sort) is necessary. A 12 W panel can easily overcharge batteries. Video. A 10 W panel isn't significantly different.

[bankerae]

Well I have some good news to report... we did a 2 day trip last weekend and the battery had more than enough juice to keep the furnace running all night (showing 1/2 discharged according to the wall meter). During the day we ran a 3,000 watt inverter generator which gave it a good charge back up. Obviously, I am now storing the trailer with the battery cable disconnected 🙂

[Ham_Radio_HF_Mo]

Good morning;

It is truly impressive to see the range of comments and recommendations for why this fellow's battery seems to drop down after only a few hours with what he has measured as only a 650ma load current

While I also have some questions about the test equipment and the measurement technique, BankerRae has been consistent in the value that he has reported, and it is similar to the "OFF" or parasitic current draw for the control systems involved as reported by others. He has also stated that when taken to a battery shop, the subject battery failed the load test, and he has installed a new battery, and now he will be trying the new battery to see how it performs in the circuit.

Still, the discussion on the topic does demonstrate that there are many people on the forum with knowledge and experience with the electrical systems for a motor home. This is a valuable resource for the RV community.

One suggestion I can offer for long term storage of a motor home is to connect at least a 10 Watt Silicon solar panel to the coach battery system, and leave the solar panel on the front dash behind the windshield with the motor home facing south so that the solar panel is exposed to sunlight. The 10 Watt solar panel will have right about a 625ma output current during the middle part of the day, and that should be enough for most motor homes to keep the battery charged while in storage, but not be too much to over charge the battery. A small "charge controller" {an alternative energy industry phrase for a special purpose voltage regulator) can be added between the solar panel and the battery to alleviate any concerns about overcharging, but with the size solar panel involved in this case, that is not a serious problem.

Enjoy;

Ralph,
Latté Land, Washington

[theoldwizard1]

Harvey51 wrote:

I worked hard to improve engine charging, getting rid of voltage drops in the connectors of the wire from engine to house batteries, eliminating the battery cutoff switch and its wires.

You are not going to win !

Most US vehicle designed/built after about 2000MY use the PCM to do "smart" charging of the battery. This means overall lower charging voltage. (I worked in Engineering for one of the Detroit 3 10 years ago.)


The best way to charge your house battery while you are driving, is to install a small (1000W) sine wave inverter and run an extension cord back to the trailer and use your favorite AC charger. You can find dc-dc converters on eBay that will take 10VDC in and step it up to 14V or more, but these are constant voltage/current and not appropriate for battery charging.

[theoldwizard1]

Harvey51 wrote:

I worked hard to improve engine charging, getting rid of voltage drops in the connectors of the wire from engine to house batteries, eliminating the battery cutoff switch and its wires.

You are not going to win !

Most US vehicle designed/built after about 2000MY use the PCM to do "smart" charging of the battery. This means overall lower charging voltage. (I worked in Engineering for one of the Detroit 3 10 years ago.)

The best way to charge your house battery while you are driving, is to install a small (<1000W) sine wave inverter and run an extension cord back to the trailer and use your favorite AC charger.

You can find dc-dc converters on eBay that will take 10VDC in and step it up to >14V, but these are constant voltage/current and not appropriate for battery charging.

[Harvey51]

I know it is tough to avoid taking the battery below 50% charge and damaging it. I did it on our first lengthy trip. We drove every day, engine charging took the batteries' voltage up over 13 volts and it stayed there until we went to bed. We didn't use the furnace during the night (April in southern British Columbia) so the first clue of my lack of understanding was the furnace not working in the morning. It soon got worse so hours of driving didn't allow any evening heating. My basic problem was too little charging (engine charging isn't very effective) and not realizing the voltage chart is overly optimistic for hours after charging. New batteries and much less use got us home fairly comfortably. We never plugged in to shore power and I now know that our old converter is pretty much useless anyway, only "charging" at 13.6 volts.

I worked hard to improve engine charging, getting rid of voltage drops in the connectors of the wire from engine to house batteries, eliminating the battery cutoff switch and its wires. LED lights reduced the power draw (fridge, lights and furnace being our only loads). That was better but I was always wondering what the state of charge was. A cheap eBay battery monitor indicating the per cent of charge all the time helped a lot. But it became obvious we needed to give up boondocking, use a generator or solar panels. We chose solar and it turned out just a 100 watt panel solved the problem completely for us doing only summer camping with modest power needs.