Batteries Not Charging While Connected to Shore Power

[Rhymmer]

Good evening,

Still struggling with the same issue as I was preparing for a job interview the last three days. I have been running the engine and generator to keep the power up.

I have tried working with the remote, checked all the lights on the panel. The remote is set for 30 amps.

There are no blinking lights.

A question I have when the generator runs are the batteries charging if all is working well?

Would there be any difference if I was hooked up to a 50 amp service as far as the inverter issue?(iam guessing not)

The inverter needs about 8 screws and a few connections undone to be removed from its compartment.

Thank you to all who have replied and been so helpful.

[Briarhopper]

Rhymmer,

My thoughts in blue. My apolgies if some seems redundant.

Still struggling with the same issue as I was preparing for a job interview the last three days. I have been running the engine and generator to keep the power up.

I have tried working with the remote, checked all the lights on the panel. The remote is set for 30 amps.

There are no blinking lights.

In an earlier post you mentioned the LEDs on 458 front panel (Solid chg and blinking invert). The two together mean the charger is on and the inverter is in standby mode.

A question I have when the generator runs are the batteries charging if all is working well?

Yes, if all is working well. However, shore power or generator will not charge the batteries if the 458 breaker is tripped. Thats the button with the 25 on it.

Would there be any difference if I was hooked up to a 50 amp service as far as the inverter issue?(iam guessing not)

It's possibly though maybe not likely. The power sharing feature of the 458 set to 30 will limit the amount of charge current going to the batteries. This is to prevent the 458 from pulling too much current and causing the shoreline breaker to trip.

The 458 does three things; It charges the batteries, as an inverter it provides power to the coach 120 volt system and it automatically switches from 120 volt shore power to inverter power if the shore power drops out. Charging and inverting are two seperate functions of the 458.

A possible scenario that fits your symptoms is:

Plugged into 30amp shore line with power sharing set to 30 and heavy 120 volt usage prevented the 458's charger from keeping the batteries up as 12 volt appliances were operated. The inverter was on but in standby mode due to being plugged into shore power. When usage tripped shore power on the second day, the 458's auto changeover function shifted the coach 120 loads to the inverter and then the 458's breaker tripped because the load was too much for the inverter. As long as the inverter is on or in standby mode it tries to pick up the coaches 120 volt loads if not connected to shore power and immediatley trips the breaker because of the load. WIth the 458's breaker tripped it stopped charging and eventually the batteries became too depleted and you awake to a dark coach.

The above may not be what happened at all, but it does fit the bits and pieces. If looking at the front panel (not remote) of the 458 shows a lit chg LED and a blinking invert LED while the shore line is plugged in and powering the coach 120 volt, then the above scenario may still fit.

If the two are lit as described while shore line is plugged up, turning the inverter off by pressing the invert button on the 458 (not the remote) once may allow you to reset the 458 breaker.

Hope this helps.

BH

[Rhymmer]

Hello to all who added comments and thoughts.

I have just returned from the shop with my RV back to the campground.

They replace the entire inverter/chrarger and all was in good working order when I left the shop.

I will set up camp and plan to enjoy July powered up.

I love driving an RV and living this lifestyle.

Thank you again for everyone who helped out.

[kenk0001]

wow...I am learning just listening/reading to this post.... Thanks for all your knowledge guys!

[rabbizigzag@comcast.net]

I have a 42 foot 2004 Monaco Camelot with 4 slides. PDQ model.

Ever since I bought this coach, I have had the same issue. I am hooked up to 50 amp shore power and usually when it rains or it's very hot and humid , the house power goes out and the inverter appears to shut down.

First they told me it was bad batteries so I replaced them. Issue repeated. Then I had to replace a Power transfer switch which i was told burned out. So did that. Now with new house batteries and a new power transfer switch, the situation continues with popping the shore supply breaker, the inverter shutting down and blinking red. I leave the coach with food and the fridge and come back to . You can imagine.....

So I went on the control panel to view the inverter and it only goes up to 30 Amp shore power. Could I have been duped by the seller who may have put a 30 amp inverter in a 50 amp coach.

At this point I just don't get it. This is an amazing coach when it runs, and the issue continues. Please help. Anybody.

Just wanted to add that I went as far as buying a new 50amp cord for the coach and a new house battery on off switch.

Thanks

[dickandlois]

Rabbiz, Welcome to FMCA,

You mentioned replacing the coach batteries and the transfer switch.

Think you should check all the electrical connections related to the shore power circuits. Make sure that both 110 circuits are present from the shore power riser and the neutral and ground connections are good.

Check all the wire terminals at all the connection points, breaker box(s), Inverter and all the ground connection and bounding straps.

Do you have the same problem of tripping the circuit breaker(s) on the generator under the same weather conditions or do things work properly when the generator is running ?

When the Charger is running are the batteries charging properly?

Rich.

[wolfe10]

rabbizigzag,

Welcome to the FMCA Forum.

Please tell us the make and model of the inverter/charger you have.

Also, confirm that it is the CG breaker, not breaker in your coach that is tripping. In only one CG, or different ones (i.e do we know for sure that the CG electrical system is correct? Roughly how many amps/what was on then the breaker tripped?

When power goes off, to all 120 VAC things go off, or just those things supplied by the inverter (i.e do things like the roof A/C's also go off)

[twest99]

Hello FMCA!

I just got a 1994 Newmar 38' motor home and I've been troubleshooting the house power system...

What I know:

Voltage at the batteries is 11.4 at best and drops below 11 when several loads (lights/fans) are on. I confirmed this voltage with a meter at the batteries.

When plugged into shore power (with house 110 VAC adapter, i.e., not 50 AMP service), voltage is still 11.4 max, and it also drops to below 11 when under load.

The batteries are not charging when plugged into shore power, i.e., they do not get above 11.4 when under shore power for a few days.

I had the charger replaced and I'm getting the same results.

Some really basic questions (my first RV experience, and no owners manual!):

The 2 house batteries are wired in series (pos to neg). Voltage across each battery (when disconnected) is ~5.6V. I expected to see two 12 volt batteries wired in parallel! Is it "standard" for an RV to use 6VDC batteries? I could see no markings on the batteries indicating the voltage, although I did see 6 cells that you can add water to (water level was good on all cells).

The charger negative is wired (grounded) to the chassis. This seems very odd. I disconnected the negative from the charger to the chassis, and ran a temp cable (used car jumper cable) from the charger negative directly back to the negative of the batteries - I made sure that the negative I attached the jumper cable to was NOT the same battery that the positive from the charger was connected to. I got the same results: 11.4VDC max.

I think my next step is to get the batteries tested to make sure that are still good, but I've never seen 6VDC batteries that are the size and shape of a 12VDC car battery...

Apologies for dump question... glad to read links to get educated - thanks for any/all help.

[wolfe10]

twest99,

Welcome to the FMCA Forum.

For house batteries, two 6 VDC batteries (usually golf cart batteries) wired in SERIES are a good choice and very common.

But your commend of 6 cells (assume you mean per battery) would indicate a 12 VDC battery. Please confirm that each battery has three cells/6 cells in the two batteries combined.

Have you confirmed that you have 120 VAC to the charger? What charger do you have?

If it is getting 120 VAC and new, check the wiring and possibly a fuse between the charger and the batteries.

Be aware that some chargers are smart enough that they won't charge a totally dead battery!

Strongly suggest you do not attempt to use any appliances such as the refrigerator until this is resolved. PC boards really have very low voltage/ voltage spikes, etc.

So, perhaps best to remove the batteries, fully charge and then have them load tested/test SG with hydrometer.

Brett

[twest99]

Brett,

Thanks for the advice... I was confused about the batteries also - yes, they each have 6 cells (6 water fill caps) per battery. They are deep cycle batteries - do they make deep cycle batteries that are 6DV and have 6 cells? The batteries are the size of a "standard" car battery.

The charger has 120 VAC, and shows a green "charge/gel" light when shore power is on. I will post make/model when I get home.

I am going to get the batteries tested tonight and will charge them... will let you know more as I do.

I did not want to complicate the post, but the system is not wired to use the inverter. Apparently this was a modification made by the previous owner (who I cannot contact to ask questions). So, the only way I have 120 VAC in the coach is when shore power is plugged in or if the generator is running.

Thanks,

Tim

[wolfe10]

Tim,

Ya, when you pull them, please post brand and model-- could there be a 6 VDC battery with 6 cells-- I guess, but have never seen one. But a reading of 5.6 VDC on each battery would correspond to a deeply discharged 6 volt battery.

Suggest you do take a picture AND mark what wires go where before disconnecting the batteries. And make absolutely sure that no appliances are turned on when you do this-- again this is to protect the PC boards.

Brett

[twest99]

Brett,

You were right! The two batteries are 6VDC deep cycle. Each battery has 3 cells. I'll try not to post something "I think" I remember...

Battery specs: US Battery 2200 XC (model num 2C3224N - stamped on case) 232 Amp hrs (20hr rate), 122 Minutes (@75 amps), 474 Minutes (@25 Amps).

I took the batteries to an auto parts store and they tested them. Each battery took almost 40 minutes to charge enough to test. Because it was an automotive tester, it was looking for CCA, so we tested it at 450 CCA, and it "passed". After charging and testing, the batteries read 5.93 VDC each.

After charging and testing I put the batteries back in the RV and hooked them back up to the charger. I configured the charger for wet batteries (hold invert button for 5 secs, select "wet" with charge button). The good news is that when all wired up I saw 11.8 volts on the whole system (5.9 + 5.9). The bad news is that when the charger had 120VAC on it, it still showed only 11.8 VDC. The charger battery negative is wired directly to the chassis, not back to the batteries... more on that to come...

The battery charger/inverter is a Xantrex Freedom 458-20 (single in, single out). The inverter is not wired. It appears shore power and the "old inverter 120 VAC out" are wired together at the charger input - Thats why my appliances only work when connected to shore power.

I found an old Newmar wiring diagram with the papers that came with the RV, and it clearly shows the battery negative going to the chassis ground, and NOT back to the batteries themselves. This is how the unit is currently wired. This is NOT what the Xantrex documents show as a standard installation. Given all the "smarts" on the charger, I bet this is at least part of my issue... your thoughts?

An aside: I've committed to a "shake down" trip this weekend with the family... if I can't figure out the charger piece before then, can I charge these two batteries with my car charger (12 VDC)? Its an old sears charger with a 2AMP, 10AMP and 50AMP (start) selector. In this way I can keep the batteries charged while we are connected to shore power via the sears charger. I would have to disconnect the Xantrex charger before doing this.

I plan to make two calls today:

1) To Newmar to ask about how to run another battery cable from the charger compartment back to the battery compartment. This sounds easy, but this coach is built very well, and is almost "hermetically" sealed between these compartments. The one cable (the positive) runs inside one of the main frame beams between the compartments and is totally sealed. Running another cable in this same way looks impossible...

2) To Xantrex to confirm that using the chassis frame is NOT an option for the negative battery cable.

Thanks in advance for your thoughts.... I will post results.

Tim

[wolfe10]

Tim,

Your battery voltage still indicates a near-dead state of charge. Use a portable battery charger to charge them up before concluding that you have a problem with the inverter/charger. 12.2 VDC is as LOW as you want to run a battery bank-- that is 50% discharged.

And, verify that the large-gauge wires from inverter to battery bank ARE connected, or it could not charge.

But, if you want inverter function, sounds like a new inverter charger is in your near future.

Brett

[twest99]

Thanks Brett. Could you explain the "50% discharged at 12.2VDC"? My simple thinking is that the bank is fully charged when the two 6VDC batteries are wired in series and they are at 12VDC. So when they came back from the auto store at 11.8VDC I thought - "close enough".

What voltage should I expect a fully charged set of batteries to have?

The batteries appear to be in good shape - no bulges.

The large gauge wires are connected. I took pictures and notes so they are back they way they were. Also cleaned the connections (sanded with 220 grit paper to remove rust/corrosion - it wasn't bad for an almost 20 year old motor home) so they are nice and shiny.

Thanks again,

Tim

[dickandlois]

Tim,

The window of a fully charged battery is rather narrow and its not only the voltage, but the current available.

A new battery should read 12.5 volts, plus or minus .5 volts. They should read between 12.25 and 12.5 volts for a 12 volt battery after setting 12 to 24 hrs.

A hydrometer reading of 1.265 or greater at 80°F indicates a full charge.

As the voltage readings drops so do the hydrometer readings and the current available.

Look at this link to get information on 12 volt batteries and charge levels.

http://www.mmbalmainauto.com.au/PDF/State_of_charge_12_volt_batteries.pdf

Rich.

[twest99]

Thanks Rich - I did not appreciate how narrow the fully charged voltage band is for batteries.

For the two 6VDC batteries I have, I assume that the 12 VDC numbers you gave me can be divided by 2 to give 6.125 and 6.25 for fully charged voltage for each battery?

I'll have to see where to get the hydrometer reading done...

Regardless, I'm gonna fully charge the batteries before I go further.

Tim

[wolfe10]

Fully charged 12 VDC battery (or two 6 VDC batteries wired in series) AT REST (no charging/no discharging for at least an hour)= 12.7 VDC.

Smart chargers (including the one in your inverter/charger) charge at different rates depending on what "mode" they are in:

Bulk mode when batteries deeply discharged: 14.2-14.5

Absorption mode as batteries approach full charge: same

Float mode after batteries are charged-- basically maintenance voltage: 13.2-13.5

So, when you first plug in your coach, your charger section of the inverter/charger is working, you should see 13+ VDC.

Brett

[kaypsmith]

Whew, now my head hurts!!!! Ha-Ha. All the good input from the other guys, is very true. I personally don't like the fact that a negative wire of at least the same size as the positive is not present from the batteries to the charging and or the inverting stations. But having said this, it seemed to have worked many years very well. Older units sometimes had this configuration, which depended on the chassis to negative. Biggest problem with this method is of course, the fact that chassis is steel, and the wires are copper, usually with brass ends, which are dissimilar metals. This leads to corrosion, as well as the heat that naturally occurs from the fact that electricity is being used. Keeping all terminals clean is a vital key to making them function well. Happy motoring Tim, and good luck with your problem.

Kay