What to check?

BoFuller · July 2011

I have our RV on our remote property (off-grid) and after we are away for a week or two the "low battery" signal is beeping when we arrive. I bought a Nature Power Solar battery charger a couple weeks ago, but it doesn't seem to be doing any good. It is a 18 watt/1200 mA unit (40" by 15") and I have it laying flat on the roof - nothing shading it. I'm at 6200 feet, about 15 miles SW of Seligman AZ. I also got the 8 amp controller to go with it.
I had an old multimeter and started to check the wires when I zapped it. I have a new meter now, so what should I check for when I get there?
I also have two batteries on the RV. Does it matter which one I have the clips from the controller hooked to?
The one reading I did get before the meter failed was approx 26 volts coming directly from the panel (if I remember correctly).
When I unhooked the controller from the battery then the lights on the controller lit up, but when I hooked them to the battery they go out.
I turn off the water pump, the fridge, and the lights. There is a little green light on the control panel but surely that isn't using more than the solar panel can produce. I have disconnected the CO sensing unit as it was beeping (it was a couple months past the expiration date), and we removed the smoke alarm also. I need to replace both.
I usually run the generator for awhile just before we leave so the idiot light on the wall says it is charged.
What can be wrong and what do I check?

Thanks, Bo

Cariboocoot · July 2011

Re: What to check?

Basically 18 Watts won't do much for either of the batteries, much less both. They are probably at least 100 Amp hours apiece, and 1.2 Amps of best-case-scenario sun is barely enough to stay ahead of self-discharge.

You need to find out what your batteries are and how they are wired. That 18 Watt panel was probably a waste of money.

bluewickedburner · July 2011

Re: What to check?

You asked "What can be wrong and what do I check?"

You show up and the very first thing you should do is check your master battery disconnect and if the batteries aren't disconnected, do that before anything else.

Next:

1. Check the physical condition of the batteries. Are they bulged, misshapen? Leaking? If so you probably need new batteries.

2. If your batteries have caps on them, check to see if the batteries have water. Wear some safety goggles when you do this. If the plates are covered good so far. If they don't have caps, not much you can do about water.

3. If you have a phone with a camera, take a picture of the battery interconnects for reference. Draw a small schematic if not.

4. Go inside and check the refer to make sure it is off. Same with all other electrical appliances.

5. Make sure your water heater is off as is the heater and AC.

What you've done so far is make sure that if anything is dreadfully wrong and going wrong, you've stopped it. Not saying you've corrected anything yet.

6. You have two batteries. Only two or two plus one or more for the engine?

Assuming 2, one for the engine (chassis) and one for living (coach or house battery)

7. Switch the battery disconnect to "ON". Start the RV if a motorhome. Some people say RV and motorhome interchangeably. If it starts, good so far. Let it run for about 15 minutes. It should start again.

8. Engine off.

9. Master battery disconnect to "OFF"

10. Check the batteries one at a time for voltage. Don't check for amps, you'll probably just blow the meter. Refer to the standard voltage readings to check for preliminary health. If ok:

11. Battery disconnect to on. Start genset. Let the genset run for about 3 hours. During that time you can turn on the refer. Check other appliances for function.

12. While the genset is on, check on batteries. Are they smoking, leaking or smelling really bad? If no, continue to let genset run.

Now you have something else to figure out. Charging. That little panel you have should be hooked up to the engine battery if you have one. When you leave, set the disconnect for the engine battery to "OFF". That way the panel will try to replace the self discharge for the more critical engine battery.

Before you leave again, all battery disconnects to "OFF". That prevents any parasitic draws on the battery(s) so any panel you end up with will go to better use than powering something idle but drawing power 24x7.

For the chassis or house battery, you'll need a more powerful panel. Lots of input here on the boards about figuring size for that.

Good luck.

BoFuller · July 2011

Re: What to check?

bluewickedburner wrote: »

You asked "What can be wrong and what do I check?"

You show up and the very first thing you should do is check your master battery disconnect and if the batteries aren't disconnected, do that before anything else.
What is a master battery disconnect??Next:

1. Check the physical condition of the batteries. Are they bulged, misshapen? Leaking? If so you probably need new batteries. No leaking; no bulging; they look fine

2. If your batteries have caps on them, check to see if the batteries have water. Wear some safety goggles when you do this. If the plates are covered good so far. If they don't have caps, not much you can do about water. About a month ago I put water into each cell in both batteries. I believe one cell had the top of the plates exposed.

3. If you have a phone with a camera, take a picture of the battery interconnects for reference. Draw a small schematic if not. I'll take a picture this weekend.

4. Go inside and check the refer to make sure it is off. Same with all other electrical appliances. I turn everything off everytime.

5. Make sure your water heater is off as is the heater and AC. I always do this
What you've done so far is make sure that if anything is dreadfully wrong and going wrong, you've stopped it. Not saying you've corrected anything yet.

6. You have two batteries. Only two or two plus one or more for the engine? No engine - this is a travel trailer.

Assuming 2, one for the engine (chassis) and one for living (coach or house battery)

7. Switch the battery disconnect to "ON". Start the RV if a motorhome. Some people say RV and motorhome interchangeably. If it starts, good so far. Let it run for about 15 minutes. It should start again. NA

8. Engine off. NA

9. Master battery disconnect to "OFF" NA

10. Check the batteries one at a time for voltage. Don't check for amps, you'll probably just blow the meter. Refer to the standard voltage readings to check for preliminary health. If ok: I'll do this

11. Battery disconnect to on. Start genset. Let the genset run for about 3 hours. During that time you can turn on the refer. Check other appliances for function.

12. While the genset is on, check on batteries. Are they smoking, leaking or smelling really bad? If no, continue to let genset run. They always seem fine - no smoking, no smell
Now you have something else to figure out. Charging. That little panel you have should be hooked up to the engine battery if you have one. When you leave, set the disconnect for the engine battery to "OFF". That way the panel will try to replace the self discharge for the more critical engine battery. NA
Before you leave again, all battery disconnects to "OFF". That prevents any parasitic draws on the battery(s) so any panel you end up with will go to better use than powering something idle but drawing power 24x7.

For the chassis or house battery, you'll need a more powerful panel. Lots of input here on the boards about figuring size for that.

Good luck.

Thanks for the input. Mayber I expected too much. Maybe this panel is good for phone charging or something like that.

BoFuller · July 2011

Re: What to check?

Cariboocoot wrote: »

Basically 18 Watts won't do much for either of the batteries, much less both. They are probably at least 100 Amp hours apiece, and 1.2 Amps of best-case-scenario sun is barely enough to stay ahead of self-discharge.

You need to find out what your batteries are and how they are wired. That 18 Watt panel was probably a waste of money.

I'll take some pictures of the battery setup this weekend.

Thanks!

bluewickedburner · July 2011

Re: What to check?

Somewhere you should have a master battery disconnect, even in a travel trailer. If you don't I highly recommend you install one, they go for about 15-25 dollars depending on quality. Some have a red plastic type key interlock so that you can quickly disconnect your entire battery bank from use. I've seen some disconnects installed where the user has to reach over the batteries to get to it, defeating some of it's purpose.

Should your batteries every develop a serious safety problem, you'll want to use that disconnect instead of trying to pull a cable.

Have your battery checked. If some of the plates were dry the battery is on the downside of reliable use, depending on how long it was dry.

BoFuller · July 2011

Re: What to check?

bluewickedburner wrote: »

Somewhere you should have a master battery disconnect, even in a travel trailer. If you don't I highly recommend you install one, they go for about 15-25 dollars depending on quality. Some have a red plastic type key interlock so that you can quickly disconnect your entire battery bank from use. I've seen some disconnects installed where the user has to reach over the batteries to get to it, defeating some of it's purpose.

Should your batteries every develop a serious safety problem, you'll want to use that disconnect instead of trying to pull a cable.

Have your battery checked. If some of the plates were dry the battery is on the downside of reliable use, depending on how long it was dry.

I'll look for one this weekend. Maybe it is there and I just have not noticed it.

BB. · July 2011

Re: What to check?

When installing a disconnect--you have to make the decision if you want the Solar Charger on the Battery or the Load side of the switch (or if you want two disconnects, one for loads and a second for "chargers").

-Bill

What to check?

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