Batteries Overheating and Offgassing

[Patandlinda]

Originally Posted by John in Santa Cruz

exactly... trailer + wire to batt1+, batt1- to batt2+, batt2- to trailer -

like this,


note that GC2/T105 golf cart batts do NOT have a built in handle, you need one of these...
https://www.amazon.com/Trojan-609628.../dp/B00699WCUM

to pick them up and install them.

You sure do need one of those . The RV store I purchased from just let us take one home . He said to call him in the afternoon next day and see if he could get another from Interstate . Called him and he told me I could keep it , it was on the house !
Without that strap no way could we move those batteries! Pat

[cl3]

Originally Posted by alanmalk

Nothing wrong with that plan at all. But - a very important but - you must confirm nothing is wrong with your converter (battery charger) first - or you risk cooking the new batteries like the old ones.

Beg, borrow, or better, buy a reliable and accurate multi-meter. It will come in handy for many electrical issues.

Charge your current batteries for a half a day while keeping the loads light. A few lamps running is OK but avoid using the furnace, water pump, inverter, etc - to ensure the batteries are past the initial (bulk) charging mode. Then measure the voltage on each battery directly at the battery post with the charger running. You are looking for voltages that are around 14.4 to 14.8, and they should be virtually the same for each battery. Any voltage above 15 indicates a likely problem in the converter. And if the batteries have a voltage difference of more than 0.1 then you may have found the reason one of them cooked in the first place.

Report the voltages back to us and someone will have a diagnosis.

--
Alan

Ok, checked voltages. With batteries unconnected I got 12.25V on the battery that isn't offgassing or getting hot, 11.7V on hot, offgassing battery and when reconnected in parallel with the converter running I got 12.95V, which I assume is what the converter is putting out to the batteries. So my read would be that the low voltage, offgassing battery is bad and the converter is working correctly. Thoughts?

[alanmalk]

Originally Posted by cl3

Ok, checked voltages. With batteries unconnected I got 12.25V on the battery that isn't offgassing or getting hot, 11.7V on hot, offgassing battery and when reconnected in parallel with the converter running I got 12.95V, which I assume is what the converter is putting out to the batteries. So my read would be that the low voltage, offgassing battery is bad and the converter is working correctly. Thoughts?

First, toss the 11.7 battery - it is toast. Reconnect everything and see if you are happy for the remainder of the camping season. But perform one final check and measure the charging voltage one last time with just the working battery - just to be safe.

Next season, consider a pair of 6V batts. in series. Or a pair of 12V AGM batts. in parallel.

General note: I have been using a (matched) pair of 12V AGM batts in parallel since early 2015 and have been a happy camper. No special switching between A and B battery and no special effort to balance every last microvolt. I open the cover and look at them once per year.

--
Alan

[cl3]

Originally Posted by alanmalk

First, toss the 11.7 battery - it is toast. Reconnect everything and see if you are happy for the remainder of the camping season. But perform one final check and measure the charging voltage one last time with just the working battery - just to be safe.

Next season, consider a pair of 6V batts. in series. Or a pair of 12V AGM batts. in parallel.

General note: I have been using a (matched) pair of 12V AGM batts in parallel since early 2015 and have been a happy camper. No special switching between A and B battery and no special effort to balance every last microvolt. I open the cover and look at them once per year.

--
Alan

Took out the bad battery and connected the good one. Converter voltage still at 12.9V. I'll leave it connected for a while and see what happens. It's odd to me that the converter fan kicks on immediately. Reading the manual I thought it only is supposed to come on when needed. I plan to replace the batteries with 2 6V AGM in series once I'm sure the converter is working. Appreciate everyone's input on this.

[Ron in BC]

Originally Posted by cl3

It's odd to me that the converter fan kicks on immediately. Reading the manual I thought it only is supposed to come on when needed.

I don't think that it's odd. My comes on when I first turn it on, always has.

Ron

[padlin]

"Automatic Cooling Fan
The cooling fan in the WF-8900 Series Power Center is incremental and is controlled by the
current drawn out of the converter to the applied load. The on-board microprocessor
increases fan speed as the total load increases and decreases fan speed as the load
decreases. Unlike traditional temperature-controlled fans, the load-controlled fan provides
better component cooling by avoiding temperature spikes which can lead to premature
component failure."

The battery reading 12.25v is 60ish% charged, could be the battery is just drawing a lot of current, hence the fan runs. I'd leave it on overnight and see what the reading is in the am.

[Tford]

Another question along this same thread...
I've got 2 6V hooked up and the trailer sits in covered storage when not out on the road, so I leave it plugged in to an extension cord so it will keep the batts charged up without solar. Is our system (2014 5.0) charger smart enuff to just keep topping them off and keeping them at correct charge or does it just continue to charge? Should I just put a timer on the cord to give power to the trailer 4-6 hours a day to run the batt charging system for just that long? Don't want to overcharge the batts and cook the water out of them.

[padlin]

Yes, the stock converter will keep the batteries topped off in storage, do check the water before and after.

No worries about over charging, the converter will do fine.

Do you have a 12vdc cutoff switch? if so what state are you leaving it in storage

[Greg and Kathy]

Originally Posted by cl3

Ok, checked voltages. With batteries unconnected I got 12.25V on the battery that isn't offgassing or getting hot, 11.7V on hot, offgassing battery and when reconnected in parallel with the converter running I got 12.95V, which I assume is what the converter is putting out to the batteries. So my read would be that the low voltage, offgassing battery is bad and the converter is working correctly. Thoughts?

The battery reading 12.25 is probably dead as well. Unfortunately the dead one you removed probably killed the other one. If after a few hours of charge you let it sit disconnected for an hour and measure the voltage and it is not 12.6 or above it is bad as well

[Tford]

Originally Posted by padlin

Yes, the stock converter will keep the batteries topped off in storage, do check the water before and after.

No worries about over charging, the converter will do fine.

Do you have a 12vdc cutoff switch? if so what state are you leaving it in storage

Cutoff switch is ON...

[padlin]

Rob, I don't see anything wrong with the way you are doing it now.

[rubicon327]

Originally Posted by padlin

Yes, the stock converter will keep the batteries topped off in storage, do check the water before and after.

No worries about over charging, the converter will do fine.

Agreed. The stock WFCO 8955 charger will drop back to 13.2V trickle charge (or float) to maintain the batteries. You can keep the trailer plugged in all the time if you wish but even though there should be minimal off-gassing and water loss I second that you should keep an eye on the water levels as a routine. Have a bottle of distilled water handy for topping up.

[John in Santa Cruz]

you really should have a volt meter or battery monitor so you can check on the charging voltages. I have one oft he simple ones that plugs into the cigar socket, lets me tell whats going on at a glance.

[Patandlinda]

Originally Posted by John in Santa Cruz

you really should have a volt meter or battery monitor so you can check on the charging voltages. I have one oft he simple ones that plugs into the cigar socket, lets me tell whats going on at a glance.

Yup good advice . I may go overboard but besides a Victron battery monitor have the plug in volt meter , a volt meter constantly installed to battery . A ohm meter too. Besides checking battery water , always check the batteries . Pat

[Tford]

Originally Posted by rubicon327

Agreed. The stock WFCO 8955 charger will drop back to 13.2V trickle charge (or float) to maintain the batteries. You can keep the trailer plugged in all the time if you wish but even though there should be minimal off-gassing and water loss I second that you should keep an eye on the water levels as a routine. Have a bottle of distilled water handy for topping up.

Yup, put the flow rite battery filling system on it right after getting new batts last year, so that’s easier now. I check them with the voltmeter occasionally as well.

Thanks folks!

[wxguy]

Originally Posted by Vermilye

It is possible that there is a bad cell in the battery that overheats. Try disconnecting it & measure the voltage. Fully charged, it should be in the neighborhood of 12.7V . If it is well below this, take it to a battery or auto store & get it tested.

A bad converter will also cause gassing & heating, but that would likely happen to both batteries.

One way to solve the propane alarm problem is to go to AGM batteries (it can happen with good 6V or 12V flooded batteries), either 12V in parallel or a pair of 6V in series. I like the Lifeline 6V AGMs, but they are more expensive than most. My solution was to switch to lithium, but that is even more expensive!
A pair of

I think Vermilye is on the right track here. But, if I tested the battery (isolated from the rest of the electrical system) and it was anything under about 12.5V w/ no load, I would consider it a brick, recycle it, and replace w/ new. If the other battery was well used, I would replace it at the same time. Its a few hundred dollars well-spent IMO for piece of mind.

Now I gotta ask, what are the advantages of 2 6V batteries in series vs two 12V batteries in ||? I see lots of mentions of the 2 6V in series so I assume there is a good reason. Enlighten me briefly, PLZ.

[John in Santa Cruz]

Originally Posted by wxguy

I think Vermilye is on the right track here. But, if I tested the battery (isolated from the rest of the electrical system) and it was anything under about 12.5V w/ no load, I would consider it a brick, recycle it, and replace w/ new. If the other battery was well used, I would replace it at the same time. Its a few hundred dollars well-spent IMO for piece of mind.

Now I gotta ask, what are the advantages of 2 6V batteries in series vs two 12V batteries in ||? I see lots of mentions of the 2 6V in series so I assume there is a good reason. Enlighten me briefly, PLZ.

2 6V in series, both batteries always see the same current, charging and discharging, so they stay well balanced. 2 12V in parallel, any variation in the batteries, the weaker one will drag the whole thing down and the stronger one will discharge into the weaker one. Also, golf cart 6V batteries have MUCH thicker and heavier lead plates which means they last much longer, and are much more suitable as deep cycle batteries.

[Brian B-P]

Originally Posted by John in Santa Cruz

Also, golf cart 6V batteries have MUCH thicker and heavier lead plates which means they last much longer, and are much more suitable as deep cycle batteries.

I would say, instead, that good deep-cycle batteries are most readily and affordably available in the "golf cart" 6-volt format, although they are also available (with identical and equally suitable construction) in 2V, 4V, 8V, and 12V. In contrast, most readily available and inexpensive 12-volt batteries are not as suitably constructed, even if they are labelled "deep cycle".

[John in Santa Cruz]

a 6V golf cart batt has only 3 cells, a 12V batt has 6, and if its the same size, the cells are half as big. sure, there's the marine 8D 12V battery, thats 180 lbs, and the size of two golf cart batts put end to end.

[Brian B-P]

Originally Posted by John in Santa Cruz

a 6V golf cart batt has only 3 cells, a 12V batt has 6, and if its the same size, the cells are half as big. sure, there's the marine 8D 12V battery, thats 180 lbs, and the size of two golf cart batts put end to end.

But in a 12 volt system you would need two of those 6 V batteries, and obviously twice as much battery is, well, twice as much battery. If you compare the same volume of battery (two boxes) in the same construction it doesn't matter how many cells there are, there's the same amount of lead and the plates can be the same thickness. With twice as many cells (two 12 V batteries in parallel) there are just half as many plates per cell, but same number of the same plates in total.

If you want another way to compare them, imagine one regular-sized 12 V battery (say 6" wide, 7" tall, and 12" long) and two half-sized 6 V battery beside it (so 6" wide, 7" tall, and 6" long). Every cell in both cases is the same width, height, and length (2"), so if they're from the same product series the plates in them will be the same.

Lead-acid batteries are stacks of lead plates in an electrolyte, and there are lots of variations in the construction of the plates. The number of plastic boxes they're split into isn't important, except for the practical matter of whether or not a person can lift the box to install it.