How Do MH Engine Batteries Receive Their Charge?

[hermanmullins]

The cable you now have is 1/0 sometimes referred to as "One  Ought" Your best bet would be to purchase the cable from a Welding Supply House if you are planning on making them yourself.  A hardware store is a good place to find the lugs. You will need  1/0 X 5/16 copper lugs for your house batteries since they have threaded post.

Herman

[wolfe10]

You can also purchase  "properly large-gauge" pre-made interconnects from any marine dealer.  Yes, more expensive, but the pre-tinned (marine grade) wire is MUCH more resistant to corrosion than raw copper.

[wildebill308]

Yes, like Brett said the tined and sealed cabling will outlast the non tined welding cable. Hearer is one source.

http://www.bestboatwire.com/

Bill

[manholt]

Still cheaper than replacing one battery, all 4 around $800+ for AGM's!

[rsbilledwards]

I just went thru this exercise using 2/0 wire, regular welding cable. I used closed ended lugs and adhesive laden shrink tube. Before assembly and crimping I used dialectic grease in the lugs. Then they were crimped with a crimping tool, not a hammer like I have seen used before. Then the adhesive laden shrink tube was used, red for positive and black for negative.  I did this on the previous coach and no corrosion issues in seven years. Dialectic grease was used on all battery connections during assembly. Amazon is an excellent source for the heavy wire and reasonably priced. 

[bigbillsd]

On 12/6/2017 at 11:07 AM, bburns8 said:

  Only appliance turned on was the refrigerator in AC mode.

Unplugged from Shore power

Voltage at chassis batteries tested in series:  12.82v
Voltage at house banks batteries tested in series:   12.04v

 

I am wondering about this.  If the fridge is in AC mode and he is unplugged from Shore-power,  is the inverter creating that 120 volts to power the fridge?  The AC heaters for an absorption fridge use a lot of amps. 

Could that explain the voltage drop on the house battery's?  

I reread thru the thread and couldn't find any info on his fridge.  

[wolfe10]

Good question.

It would be extremely unusual for the refrigerator 120 VAC outlet to be off the inverter-- would really negate the purpose of having an absorption refrigerator.

But, super easy to check. 

Unplug from shore power, generator off, inverter off:

Either plug voltmeter or any 120 VAC device (hair dryer works well) into the outlet behind the refrigerator that the refrigerator is normally plugged into.  Better be no power there.

 

Now, turn on inverter and repeat test.  Very likely it will still be "no power".  If there is power,  look for another place to plug in.  I have even seen the two outlet plugs behind the refrigerator with one powered by shore only and the other by inverter.  Generally the inverter outlet is for an ice maker.

[bburns8]

I replaced my 4 house batteries a week ago and replaced the 4 battery cables today.

Here is the voltage readings I am getting now in series on the house batteries.

Unplugged from shore power, inverter OFF charger OFF

Voltage at house banks batteries tested in series:   12.88v

 

Unplugged from shore power, inverter ON charger ON

Voltage at house banks batteries tested in series:   12.25v

 

Plugged into shore power, inverter ON charger ON

Voltage at house banks batteries tested in series:   14.38v

Please advise is these voltage readings are normal?

Thank you.

[kaypsmith]

12.88 is a good reading with no load and batteries rested, 12.25 sounds pretty normal with inverter/charger on especially if there is a normal load on the inverter, and 14.38 would be expected when in bulk mode, this is where it would go when first turned on to shore power.

[dickandlois]

bburns, 

Replying to your voltage readings. 

         Unplugged from shore power, inverter OFF charger OFF

Voltage at house banks batteries tested in series:   12.88v   Good

 

        Unplugged from shore power, inverter ON charger ON

Voltage at house banks batteries tested in series:   12.25v   A little lower then I would expect, BUT if there is any load Microwave clock, florescent light or some other light load it is well within  the nominal range

 

        Plugged into shore power, inverter ON charger ON

Voltage at house banks batteries tested in series:   14.38v   A good float level voltage.

Rich.

[bburns8]

 Unplugged from shore power, inverter ON charger ON

Voltage at house banks batteries tested in series:   12.25v  - There was no load when tested.

 

[bburns8]

When plugged into shore power we are now hearing a high pitched electrical whine from the converter, regardless of load, and it's not the fan.  I'm plugged into shore power, inverter OFF, charger ON.

Has anyone experienced this? Any ideas what's causing this?

[wolfe10]

You mention "converter".  Are you talking about your inverter/charger? Or do you really have a separate converter?

And, if inverter/charger, do you really have the ability to turn off/on the charger function?

[bburns8]

I meant inverter/charger.  Yes, there is a on/off button for the charger and a on/off button for the inverter on the inverter/charger itself and a on/off button for the inverter inside the coach.

[wolfe10]

Would suggest your next call be to the technical support department of your inverter/charger manufacturer.  If possible, do it from the coach so you can let them listen to the sound.

Also, have written down:

Shore power voltage (120 VAC ideal)

House batter bank voltage

Any readings from the inverter/charger remote control panel.

[dickandlois]

1 hour ago, bburns8 said:

When plugged into shore power we are now hearing a high pitched electrical whine from the converter, regardless of load, and it's not the fan.  I'm plugged into shore power, inverter OFF, charger ON.

Has anyone experienced this? Any ideas what's causing this?

Recheck the series / parallel wiring for the house batteries and that the battery wires for the chassis 12 volt batteries are correct. I did rewire mine wrong one time and the charger was not happy. Humbling experience, but if one places there fingers into a mouse trap enough times it will get you. 

Rich.

[BillAdams]

3 hours ago, bburns8 said:

 Unplugged from shore power, inverter ON charger ON

Voltage at house banks batteries tested in series:   12.25v  - There was no load when tested.

 

So try this.  Unplugged from shore power, Inverter OFF, Charger OFF (even though charger does nothing without shore or generator power).

12.25V is a reading for a battery that is about 1/2 discharged.  12V is dead and something around 12.6ish would be fully charged, no load, and not on a charger.

[bburns8]

8 hours ago, BillAdams said:

So try this.  Unplugged from shore power, Inverter OFF, Charger OFF (even though charger does nothing without shore or generator power).

12.25V is a reading for a battery that is about 1/2 discharged.  12V is dead and something around 12.6ish would be fully charged, no load, and not on a charger.

I had tested the batteries in series when I was unplugged from shore power with the Inverter OFF, Charger OFF and I had a 12.88v.

[bburns8]

10 hours ago, DickandLois said:

Recheck the series / parallel wiring for the house batteries and that the battery wires for the chassis 12 volt batteries are correct. I did rewire mine wrong one time and the charger was not happy. Humbling experience, but if one places there fingers into a mouse trap enough times it will get you. 

Rich.

Thanks Rich.  I'll recheck.

[bburns8]

10 hours ago, wolfe10 said:

Would suggest your next call be to the technical support department of your inverter/charger manufacturer.  If possible, do it from the coach so you can let them listen to the sound.

Also, have written down:

Shore power voltage (120 VAC ideal)

House batter bank voltage

Any readings from the inverter/charger remote control panel.

Thank you Wolfe10.

[bburns8]

There is a humming sound coming from the inverter/charger.

I'm plugged into shore power and turned off the inverter the sound is still there.  I turned off the inverter and turned the charger off but the humming sound is still there.

Has anyone experienced this?

[dickandlois]

1 hour ago, bburns8 said:

There is a humming sound coming from the inverter/charger.

I'm plugged into shore power and turned off the inverter the sound is still there.  I turned off the inverter and turned the charger off but the humming sound is still there.

Has anyone experienced this?

Went back to read your original post. The Inverter / Charger is OEM equipment. 

So - the humming sound is being generated from the transformer. After time the steel plates used to make the transformer start to vibrate / buzz. This is caused by the brake down of the lacquer used to isolate them. It do not effect the operation of the system, but they do buzz. No real fix for that problem - for the majority of owners or even the service centers. Should you send the unit back to Xantrex - they could replace the transformer. The Total cost of the labor and shipping gets to a point close to replacing it. 

So I would just use it until it has electrical issues and then replace it. Think you will find it is a 2500 Watt / Modified sine-wave  unit. They are still in production and used frequently in many new coaches. The Pure sine wave units are more expensive, but do have the ability to be used with the newer electronic equipment that use Computer style circuits and control systems.

Hope this information helps answer your question(s).

Rich.

[manholt]

Thank you, Rich.  I just learned something new!

Happy New Year to you & Lois!

[bburns8]

1 hour ago, DickandLois said:

Went back to read your original post. The Inverter / Charger is OEM equipment. 

So - the humming sound is being generated from the transformer. After time the steel plates used to make the transformer start to vibrate / buzz. This is caused by the brake down of the lacquer used to isolate them. It do not effect the operation of the system, but they do buzz. No real fix for that problem - for the majority of owners or even the service centers. Should you send the unit back to Xantrex - they could replace the transformer. The Total cost of the labor and shipping gets to a point close to replacing it. 

So I would just use it until it has electrical issues and then replace it. Think you will find it is a 2500 Watt / Modified sine-wave  unit. They are still in production and used frequently in many new coaches. The Pure sine wave units are more expensive, but do have the ability to be used with the newer electronic equipment that use Computer style circuits and control systems.

Hope this information helps answer your question(s).

Rich.

Thank you Rich.  I appreciate it.

Would the sound still be coming from the transformer even when I turned off the inverter and charger?

[dickandlois]

Would the sound still be coming from the transformer even when I turned off the inverter and charger?

YES, The reason is AC  power is going into the unit from either the line directly or through the 30 amp breaker in the power panel.  There should be no buzz when not connected to shore power or when the circuit breaker feeding the unit is off.

Do check the ground copper wire to the unit is tight as well as the ground points / connections at the breaker box and the chassis frame. That should not change things, but it is always good the check them - things just giggle loose driving down the road.

Rich.