Community Forums

Dogpatch · 07-10-2016, 09:47 AM

In my 2010 Cardinal 3450RL, when I plug in my fifth wheel and leave my battery switch on, I can hear the the 12v battery that is connected to the controller boiling and smell rotten eggs. My two 12v batteries are connected in series. Both negative and positive wires are connected to the first battery. Should the positive charge wire be connected to the first and negative to the second?

I replaced one battery that was first in line because it boiled the water level too low so I moved the original second battery into first position and put the new in second. When charging while plugged in, I checked with my meter and it's charging at 13.6 Amps.

Not sure what's happening. When I turn off the battery switch and use my smart charger, the batteries charge fine. Water level is just up to the plastic on the hole. I do find that the battery charge level drops over time even with the battery switch in off.
Both batteries are Interstate and same size albeit one in position 2 is newer.

An ideas would be appreciated.

glennwest · 07-10-2016, 09:57 AM

Have you had the batteries checked? Sounds like shorted cells.

dennis45 · 07-10-2016, 09:58 AM

Quote:

Originally Posted by Dogpatch

In my 2010 Cardinal 3450RL, when I plug in my fifth wheel and leave my battery switch on, I can hear the the 12v battery that is connected to the controller boiling and smell rotten eggs. My two 12v batteries are connected in series. Both negative and positive wires are connected to the first battery. Should the positive charge wire be connected to the first and negative to the second?

I replaced one battery that was first in line because it boiled the water level too low so I moved the original second battery into first position and put the new in second. When charging while plugged in, I checked with my meter and it's charging at 13.6 Amps.

Not sure what's happening. When I turn off the battery switch and use my smart charger, the batteries charge fine. Water level is just up to the plastic on the hole. I do find that the battery charge level drops over time even with the battery switch in off.
Both batteries are Interstate and same size albeit one in position 2 is newer.

An ideas would be appreciated.

Hi Les,

If read read your post right, the battery connections are correct. Have you measured the voltage at the batteries. Should be 13.6 VDC
Not a good idea to replace one battery of a set. The converter will try to maintain the poorest battery of the two and overcharge the good one resulting in two bad batteries.
I would replace both and check the convert output to confirm proper charging voltage.

King Clark · 07-10-2016, 10:18 AM

A fully charged battery with no draw should not need 13.6 volts going into it. What are your readings without the charger?
Is there a voltage regulator that perhaps is not operating properly?
A new battery not connected to a charger of any kind with zero draw should show 13.6 volts, as it drops a small amount of replacement voltage will suffice. A full hit has to go somewhere and without a draw on the battery the only thing it can do is cook the battery.

mel s · 07-10-2016, 10:33 AM

Quote:

Originally Posted by Dogpatch

In my 2010 Cardinal 3450RL, when I plug in my fifth wheel and leave my battery switch on, I can hear the the 12v battery that is connected to the controller boiling and smell rotten eggs. My two 12v batteries are connected in series. Both negative and positive wires are connected to the first battery. Should the positive charge wire be connected to the first and negative to the second?

I replaced one battery that was first in line because it boiled the water level too low so I moved the original second battery into first position and put the new in second. When charging while plugged in, I checked with my meter and it's charging at 13.6 Amps.

Not sure what's happening. When I turn off the battery switch and use my smart charger, the batteries charge fine. Water level is just up to the plastic on the hole. I do find that the battery charge level drops over time even with the battery switch in off.
Both batteries are Interstate and same size albeit one in position 2 is newer.

An ideas would be appreciated.

Dogpatch
Since a separate smart charger does charge the batteries correctly without boiling them...the problem seems to be with/in your on-board charger.

Methinks either your on-board charger has malfunctioned.... or the adjustable settings, (if that charger has adjustable settings), are not set correctly.
If you have an owners manual for your on-board charger it will explain how to correctly set the various adjustments to match the batteries in your RV.

What is the make and model number if the on-board battery charger. (or inverter/charger), in your RV?

Mel
'96 Safari

Dogpatch · 07-10-2016, 10:39 AM

Quote:

Originally Posted by mel s

Dogpatch
Since a separate smart charger does charge the batteries correctly without boiling them...the problem seems to be with/in your on-board charger.

Methinks either your on-board charger has malfunctioned.... or the adjustable settings, (if that charger has adjustable settings), are not set correctly.
If you have an owners manual for your on-board charger it will explain how to correctly set the various adjustments to match the batteries in your RV.

What is the make and model number if the on-board battery charger. (or inverter/charger), in your RV?

Mel
'96 Safari

I'll have to check and get back to you Mel.

plasma800 · 07-10-2016, 10:44 AM

it would be nice to identify the charger you have. Some chargers are just darn near a single stage charger. Swap that out for a 4 stage charger, and you'll never have that problem again. Progressive Dynamics makes very popular models on this front.

My airstream charger would absolutely boil my batteries if I wasn't on top of the water constantly, and it did. All it takes is for one cell to even remotely expose the lead plate to air, and then the process accelerates rapidly! I yanked that crappy charger and installed a 4 stage, and out of habit, still stay on top of the water - checking the water once every 30 days no matter what.

Dogpatch · 07-10-2016, 10:46 AM

Quote:

Originally Posted by King Clark

A fully charged battery with no draw should not need 13.6 volts going into it. What are your readings without the charger?
Is there a voltage regulator that perhaps is not operating properly?
A new battery not connected to a charger of any kind with zero draw should show 13.6 volts, as it drops a small amount of replacement voltage will suffice. A full hit has to go somewhere and without a draw on the battery the only thing it can do is cook the battery.

When I get a minute, I'll disconnect the house charger and check the output. I'll let you know.

jelag · 07-10-2016, 03:03 PM

Geez.. I'm confused here... putting (2) 12volt batteries in series as mention in the first post... suggests a 24volt system... if in fact he has put them in series is a problem.. OR is this (2) 6 volt batteries in series and than installed in parallel with his current 12v battery???

However he states that the positive connection are connected together and the negative connections are connected together... that's a parallel connection...

If any of these batteries have a bad cell... than the bad cell could in fact cause the batteries to boil at a sub normal voltage.... and the way to find this out is with a battery hydrometer.... the readings.... based on the level of charge at the time should be with in .2 of each other.. or if you understand how to take and compare cell voltage tests... those reading should be within .2 of each other....

I assume when the author of the post tested the system with his meter.... he said 13.6 amps but he actually tested it with a volt meter... and the system voltage at that test was 13.6 volts... if that is the case... 13.6 volts is not enough voltage when put across (3) 12 VDC batteries in parallel to cause boiling UNLESS, UNLESS he does have a bad cell or the battery charger @ 13.6 volts has the ability to charge at 75 amps or higher... the batteries are fully charged.... and are hot to the touch.. and under these conditions he could be boiling the batteries... I'd venture to guess that he actually has a bad battery or 2 with at least 1 bad cell per battery....

What the poster needs is a little better understanding of series/parallel circuits, volts/amps and the understanding of ohm's law, and his better understanding of charging circuits for us to fully understand his problem and help...

Dogpatch · 07-10-2016, 03:34 PM

My bad. 2-12v are wired in parallel not series.

nothermark · 07-10-2016, 04:28 PM

If you have a parallel setup and one battery is boiling off liquid that one probably has a problem. In that case removing a lead to it and seeing of the system works with the other battery is a reasonable approach.

MtnTrek · 07-11-2016, 03:54 AM

Yeah, there should be manufactured dates on the battery tops. Mismatched batteries will default / degrade to the lowest common denominator or bad cell. Might want to budget for some new 6V.
Parallel setups can get funky that way quickly, larger arrays may require equalizing. Often with a hygrometer and accurate meter & load source.
Jelag makes some great suggestions.
Ideally a multi-stage inverter / converter with an external battery temp. probe which would throttle to avoid overheating during bulk and absorb segments vastly prolonging service life of an array.
Good luck.