Battery Low DC

[RufussSewell]

I've had some strange issues with my power system since I bought my RV in September. Now it seems my gen isn't charging my house batteries. I'll try to break down the history:

1997 Beaver Patriot Class A 37'

We're a band and have been living in it full time since September. Usually the gen is on full time since we sleep in parking lots.

Initially everything was fine, but after a month or so the chassis batteries started draining over night even though the generator was running. I took it to the shop and they installed a battery charger that plugs into a wall socket in the bay. This fixed our chassis battery issue.

Now, for the last week or so our fridge starts saying Lo DC if the main engine is off but the gen is on. If we sleep, the DC completely dies and the fridge turns off spoiling our food.

The panel that shows power share, inverter etc is showing very low DC and no ability to power share. We usually set it to 50 amps, but now it will only go to 5 amps even with the engine running.

Any clues what to try next?

[Melmoses]

First I would check the circuit breakers on the generator itself. Not being familiar with your coach I don't have an idea what generator you have but there should be circuit breakers somewhere on the generator itself. If it is popped it won't allow power to the coach. Running the house batteries down that low several times has probably killed them and they won't hold a charge. If you have an inverter, they usually have a charger built into them to keep the house batteries charged. So it could be that the charger portion of the inverter has gone bad. On my coach, there is a 300 amp flat fuse (doesn't look like a "normal" fuse that passes power through via the inverter. You need a multi-meter to check for amps on both sides of the fuse. But truth be told, I think you need to take it to a good RV repair place for them to trace the problem. They can use a hydrometer on the batteries to see if they can be saved, they can check out the circuit breakers on the generator and check out the inverter charger. These problems can be hard to find if you aren't familiar with them.

[Libero]

There are many things that could be wrong, You said it was in a shop and they put a battery charger in for your chassis battery. I hope it is a 3 stage charger. There were other options, But your issue is now with your house batteries.

I presume you have checked all fuses and breakers and connections and for the following you need a voltmeter and a Hydrometer.

1 Have you checked the electrolyte levels - just by looking? Liquid should be above the plates,

2 Have you checked the specific gravity of each cell? (Hydrometer required)

2 have you checked the voltage on the batteries when the gen or shore power is there? If charging, it should read about 13.5v. (Voltmeter required)

3. Have you checked the voltage on the house and engine batteries with the engine running? It should read about 14v if connected to your house batteries.

After you have done the above, you might report back with the results if you have not found the problem area.

Good luck

PS - my response has duplicated some if the above post - we were posting at the same time.

No need to check "Amps" (current flow) on each side of a fuse. Actually if a fuse is blown, there will not be any current, measured as "Amps", at either side of the blown fuse, but there would be voltage on one side if nothing else is wrong.

[GaryKD]

Hi RufussSewell,
Gut feel says the batteries are toast. Good advice has already been posted. The batteries need to be tested. Ensure they are fully charged. Each battery should be load tested. This will require a tool. Batteries+ or any auto parts or repair shop should have a load test tool. That will tell you, very quickly, if you have a battery problem or a charging problem. If the batteries fail a load test, the first step is to replace the batteries.

Then consider ensuring they are being charged when the generator is running or you are connected to shore power.

Lastly, make sure you understand if the coach batteries are being charged with the generator off and the engine on (like going down the road). Some charge the coach batteries from the engine alternator and some do not. This is nothing that needs to be fixed or changed. It is something you need to understand.

[wa8yxm]

I too wonder the age of the house (And chassis) batteries... Mine died at 8.5 and are awaiting replacement (Well the OEM ones, I still have a few others)

[RufussSewell]

Ok, I went to a shop. The batteries are toast so I'll replace them. They said the inverter isn't charging the batteries. They couldn't find the fuse but recommended I replace the whole unit. It'll be over $1000. I still think there's a bad fuse between the charger/inverter and the battery. I just can't find it. It's a Heart Freedom Combo 2000. The manual says the fuse is in the middle of the cable going to the battery.

If that doesn't work can I just buy a charger for the house batteries? Which one should I get if so?

["007"]

This link information may help you not same coach but you maybe able to use information.
Your converter portion is what charges your house batteries if that is gone you could use a 12v battery charger if its of a high rating for battery bank and not over charge your batteries.
If they are wet cell batteries water levels need to be check periodically if AGM's less of a problem.

12v battery system--------12v wiring systems

In my signature below are three links with added information and QT's # 3 has inverter/converter systems that may help you.

[2NewRVers]

Originally Posted by RufussSewell

Ok, I went to a shop. The batteries are toast so I'll replace them. They said the inverter isn't charging the batteries. They couldn't find the fuse but recommended I replace the whole unit. It'll be over $1000. I still think there's a bad fuse between the charger/inverter and the battery. I just can't find it. It's a Heart Freedom Combo 2000. The manual says the fuse is in the middle of the cable going to the battery. If that doesn't work can I just buy a charger for the house batteries? Which one should I get if so?

Good luck, what kind of music does your band play?

[Libero]

If your batteries are too low. Then your charger likely has a safety relay that needs sufficient back voltage to engage a relay to enable a DC output connection from the charger to your batteries. (Most good chargers have low and high voltage protection circuitry and I suspect the unit you have has this feature.)

If you let your batteries run low on electrolyte and they will not take a charge, or there are internal shorts or dead cells etc in a battery the end result of either condition is a voltage below the charger threshold limit.

I did not see any voltage readings in your posts or info if the batteries charge from the alternator. Perhaps I missed that info. Using the App and can't look back at posts while I am replying.

You did say the batteries needed replacement so I would get the new batteries first and then see if your charger works. Or connect your charger to your charged chassis battery and see if the voltage goes up to 13+V.. If you do not have a voltmeter (better a multimeter) , then this is the time to get one right now, an essential tool for any RVer and they are cheap. So is the hydrometer essential if you have open wet cell batteries.

Good luck. Battery maintenance is essential. Don't let the electrolyte get below the plates.

Hope my comments help.

[Libero]

Sorry. I did not comment on your question re getting another "stand alone" battery charger. I do not have a specific brand to recommend, however if you get one, I suggest it should (make that must) be a 3 stage charger.

If it is not a 3 stage unit then expect your batteries to need replacing more often. There are many deeper technical aspects that explain why this is.

Re a fuse. A good installation would call for a fuse between your charger and your batteries. That sould be easy to spot by following the DC wire from the charger to the battery terminals. You could also check continuity between the battery terminal and the charger connection.

As a parting shot, I presume all connections are clean and tight. Good thing to check as part of your PM routine.

Good luck

[RufussSewell]

Ok, I found the busted fuse! It's just after something called an ASC battery charge regulator. There is a 15 and 10 amp fuse. The 15 is blown.

I'll change that out and the batteries and check back in.

[Libero]

Hmmm interesting, battery charge regulators are often associated with solar systems. Does your coach have solar cells or is it preconfigured for solar panel installation. Just a thought,

If you have a coach DC schematic it should show the function of that device and I suspect an in-line fuse between your charger and battery would be much more than 15A if you have one. A continuity check would reveal any open circuit,

[Bryan H]

One quick idea from my recent experience. Had similar symptons as you. I thought it was the converter. As I was removing it, I noticed the output line connection was not securely fastened to the converter. It would sometimes charge, sometimes not. Tightened the connection and fixed the problem.

[Libero]

Originally Posted by Bryan H

One quick idea from my recent experience. Had similar symptons as you. I thought it was the converter. As I was removing it, I noticed the output line connection was not securely fastened to the converter. It would sometimes charge, sometimes not. Tightened the connection and fixed the problem.

Bryan H

X2 as I noted in a previous post and good to reinforce this aspect.

Electrical Troubleshooting 101:

Check switches/breakers, fuses and indeed, CONNECTIONS as a first run through any electrical fault finding after one has determined there is source power. So often bad connections are the cause of more severe electrical problems.

Routine PM checks often catch loose or corroded connections.