Coach Batteries Boiling

[bluepill]

Tom - I feel your pain. Some thoughts:


As already mentioned, anything above 14.4 volts in the alternator charging (vs. converter) mode is just too high. Multi-stage converters with an equalization mode can go up to around 14.8 volts for a time during that process. Therefore, make sure that you are not connected to shore power or have an inverter turned on while testing the alternator charging system, as the converter could be the source of the extra voltage.


Second thought is that a bad chassis battery (shorted cell, etc.) might be causing the alternator sense voltage to be false. Suggestion: Disconnect the chassis battery (s) at the negative posts, then run good jumper cables to a known good battery in another vehicle. Re-run yours tests and look for any different results.


Do buy a hydrometer. They are necessary for proper testing and maintenance. Get a true float type (not the type with multiple balls) like this one:


http://www.amazon.com/OTC-4619-Profe.../dp/B0050SFVHO


Best of luck.

[l1v3fr33ord1]

Tom-

Hmm... Have you checked to make sure the house battery ground is still attached to the frame? Mine (2 AWG) snapped off at the Burndy fitting, and was hanging in midair. I can't see how this would cause your symptoms, but you can add it to your "other things to check" list.

Mark

[Big-Foot]

I have had a single diode in the 3 diode rectifier bridge short out in an alternator I had once.. Showed over 15v charging. We put the shop oscilloscope on it and it showed an alternating wave-form on the hot line.. Replaced the bridge and we were in good shape once again. That was on an older 100 amp alternator with an internal regulator.. I believe it was a Delcotron brand unit.

Be very careful around any charging or discharging batteries as they don't need much to ignite that gas.. I had a battery blow up in my face when I was a young man working in a shop. Safety glasses protected my eyes but did nothing for my face, hair and clothing..

Good luck!


Regards - Randy & Dar
2015 F350 CC-DRW-409 Diesel / 2008 Rage'n Stryker 4005 Toy Hauler / 2014 Arctic Cat Wildcat Trail-XT
Sent from my iPad using iRV2 - RV Forum

[41pu]

I worked in a Auto Electric shop for years .
When a load test was preformed on a battery, we always watched the cells for signs of bubbles while under load which was a indication of a bad or shorted cell.
The battery would still show a good hydrometer reading..
Always wear safety glasses.....

[Big-Foot]

When wet cell batteries charge or discharge, there will always be "some" bubbling of the electrolyte - this is normal. However, boiling is caused by either an excessive charge or discharge rate and is quite hazardous as noted earlier.
A shorted cell may show signs of boiling, or bubbling at a rate greater than its neighbors. An "open" (disconnected) cell will show no signs of bubbling during either a charge or discharge scenario.



Regards - Randy & Dar
2015 F350 CC-DRW-409 Diesel / 2008 Rage'n Stryker 4005 Toy Hauler / 2014 Arctic Cat Wildcat Trail-XT
Sent from my iPad using iRV2 - RV Forum

[Tom Lopez]

First "THANKS TO ALL" for your ideas and suggestions to solve my problem. They were all most helpful. I did try almost all of them and they all were logical and sound. After all was said and done and all the reading and research on the internet about batteries, alternators, and charging systems everything leads back to the batteries. Regardless of the batteries showing GOOD they must be BAD.

Therefore I purchased two new Duracell Ultra Golf Cart Pro 6Volt 20AH Cap 230 batteries and installed them. I ran engine for one hour with no heat, boiling, and only tiny bubbles that look to be normal. I then took the MH on a 130 mile trip and encountered the same, everything seems normal.

My scan gauge however still shows amps running up and down 14.4 - 15.1 never resting on any one number only momentarily. At the end of the trip the numbers seem to be at 14.3 - 14.6.

I will continue monitoring them as I have another 1,000 mile trip coming soon. Everyone please still send me your alternator charging numbers so I can compare mine with yours. Some say mine are high. Some say they are fine. I don't know which is correct. I need to compare.

THANKS SO SO SO SO MUCH for your wisdom and advice.

[tropical36]

Originally Posted by Tom Lopez

First "THANKS TO ALL" for your ideas and suggestions to solve my problem. They were all most helpful. I did try almost all of them and they all were logical and sound. After all was said and done and all the reading and research on the internet about batteries, alternators, and charging systems everything leads back to the batteries. Regardless of the batteries showing GOOD they must be BAD.

Therefore I purchased two new Duracell Ultra Golf Cart Pro 6Volt 20AH Cap 230 batteries and installed them. I ran engine for one hour with no heat, boiling, and only tiny bubbles that look to be normal. I then took the MH on a 130 mile trip and encountered the same, everything seems normal.

My scan gauge however still shows amps running up and down 14.4 - 15.1 never resting on any one number only momentarily. At the end of the trip the numbers seem to be at 14.3 - 14.6.

I will continue monitoring them as I have another 1,000 mile trip coming soon. Everyone please still send me your alternator charging numbers so I can compare mine with yours. Some say mine are high. Some say they are fine. I don't know which is correct. I need to compare.

THANKS SO SO SO SO MUCH for your wisdom and advice.

Like I said, throw out the batteries for beginners and good that you did that. In fact, hot and water boiling batteries scare me.
As for the charging voltage (not amps) 13+ is considered a full charge, while often seeing 14+. However, I've never seen 15v with mine.

[TQ60]

Lol15 is way over the top.

14 is more than the battery wants but as long as driving is not continuous and water monitored you should be fine.

With 2 6 volt in series the old batteries can both boil if a single cell goes towards short.

Hydrometer may not see it and per cell voltage reading may but only works when under higher current operations such as high inverter loading.

Continue to investigate your charging voltage as it seems high.

Way back in the day I had a JC Penny life time battery and changed it yearly, the alternator was charging about 14.6 to 15 if I remember.

Fixed it when they stopped honoring warranty...That was a long time ago...

[Tom Lopez]

Tested my new batteries on a 1,000 mile plus trip and all is well, no problems with charging system since install of new 6volt batteries.

I did notice that my scan guage II reflects the voltage as 14.3-15.1 while running at 60mph after the initial start up of 14.7-15.3. It runs up and down the scale only pausing for about 1/2 second or less never really resting on any single number. My dash guage however shows my volts as a steady 14.1-14.2 after the initial start up as 14.7-14.8 at same speed. I guess both gauges are correct they just read differently.

I was concerned at first because folks said that my alternator was to high when charging at anything over 14.3 but all seams to be fine.

Again a big "THANKS" to everyone for all your info and words of encouragement while I was getting this figured out.

[mel s]

Originally Posted by Tom Lopez

Tested my new batteries on a 1,000 mile plus trip and all is well, no problems with charging system since install of new 6volt batteries.

I did notice that my scan guage II reflects the voltage as 14.3-15.1 while running at 60mph after the initial start up of 14.7-15.3. It runs up and down the scale only pausing for about 1/2 second or less never really resting on any single number. My dash guage however shows my volts as a steady 14.1-14.2 after the initial start up as 14.7-14.8 at same speed. I guess both gauges are correct they just read differently.
I was concerned at first because folks said that my alternator was to high when charging at anything over 14.3 but all seams to be fine.
Again a big "THANKS" to everyone for all your info and words of encouragement while I was getting this figured out.

Tom Lopez
My ScanGauge D indicates a battery voltage of 12.5 to 13.8 when driving, (depending whether the head lights are ON and/or the heater/air cond. blower is running).
Mel
96 Safari

[twinboat]

IIMHO, You are still overcharging.

In about a year and a half your batteries may be boiling again.

[mel s]

Originally Posted by twinboat

IIMHO, You are still overcharging.
In about a year and a half your batteries may be boiling again.

twinboat
I agree!

With the proper charge voltage from my alternator, (and from my converter/charger), my 2 sets of house batteries have lasted 9+ years each.
Mel
'96 Safari

[mrt_1111]

Originally Posted by Tom Lopez

First "THANKS TO ALL" for your ideas and suggestions to solve my problem. They were all most helpful. I did try almost all of them and they all were logical and sound. After all was said and done and all the reading and research on the internet about batteries, alternators, and charging systems everything leads back to the batteries. Regardless of the batteries showing GOOD they must be BAD.

Therefore I purchased two new Duracell Ultra Golf Cart Pro 6Volt 20AH Cap 230 batteries and installed them. I ran engine for one hour with no heat, boiling, and only tiny bubbles that look to be normal. I then took the MH on a 130 mile trip and encountered the same, everything seems normal.

My scan gauge however still shows amps running up and down 14.4 - 15.1 never resting on any one number only momentarily. At the end of the trip the numbers seem to be at 14.3 - 14.6.

I will continue monitoring them as I have another 1,000 mile trip coming soon. Everyone please still send me your alternator charging numbers so I can compare mine with yours. Some say mine are high. Some say they are fine. I don't know which is correct. I need to compare.

THANKS SO SO SO SO MUCH for your wisdom and advice.

At idle engine warm
Scanguageii 14.2 volts
Volt meter at batteries 14.3 volts

Generator/PD 9260 converter 13.8 volts