House batteries seem to be overchargingOur

Our chief maintenance man (Jim) who is chief passenger in our 2910T says it looks like our house batteries are overcharging. We discussed getting AGM materiel which will cut out the maintenance ritual but may not stop the overcharging. And the thought what on earth do you turn off to get rid of the overcharging. In the class A knowing which way things flowed was a lot easier and cutting something off was possible.  Parked at our other house we have full power on 50 amp which is what we have in our unit and refrigerator is not empty or disconnected. Next trip in less than a month.  We also have access to dump for our macerator which makes that parking spot very handy.  Our unit is 2016 and still kinda short on miles.. About 8,000 now... We hope to make up for our slow warm up next spring and summer.
Anyone know the secret to this let us know. P

Do you have two 12V house batteries (hooked up in parallel), or two 6V house batteries (hooked up in series)?

I ask because it makes a difference with our PC.  Two different sets of 12V wet acid overcharged all the time, but our 6V AGMs never do.  I feel the significance is 12V-to-6V, not wet acid-to-AGM.  But I can't say for sure.  It could be the combination.

Henry- Refer to the  power converter manual that came with your  owners manual package. If you have to replace it check out  the  Progressive Dynamics converters with built-in  charge wizard.

Ron- how did you remove the black  panel on the stove  vent hood to install your voltmeter? I installed a 4 digit voltmeter directly above my converter  using a small plastic  project box.

If you have the standard Parallax converter check their website and see if your model is compatible with the 4400TAU module.  This adds a battery temperature monitor to the converter.  You need to run the sensor out to the battery compartment and then plug the TAU module into the converter.  On mine it involved removing a plate on the converter, inserting the module into the space under it and then putting the plate back on.

The module allows the converter to charge at a much higher voltage, up to 14.4 volts, and to drop that down as battery temperature increases.  No more battery boiling.  Why this is not standard equipment is very confusing to me.  I spoke on the phone with the folks at Parallax about this and they strongly suggested adding the 4400TAU to increase battery life and efficient charging.

Without the module the converter just charges away at the standard 13.7 volts until the battery boils.

http://www.parallaxpower.com/power-centers-5300-series

https://www.amazon.com/Parallax-4400TAU-Temperature-Compensated-Controller/dp/B00ZPJGYF6/ref=pd_lpo_sbs_263_t_2?_encoding=UTF8&psc=1&refRID=A8BSB3VBB6P37GRBR0FP

I feel the significance is 12V-to-6V, not wet acid-to-AGM.

Ron, I believe the difference is wet acid versus AGM.  An overcharged battery gets too hot and boils, eventually exposing the lead plates.  If constantly monitored and new distilled water is added this is not usually an issue.  The AGM design eliminates the risk of boiling and exposing the plates.  That does not mean that a poor charger does better with AGM battery, just that it will not ruin them by boiling away the fluid. 

The standard Parallax converter / charger just chugs away with no real way of knowing what is going on at the battery.  Most of the time that is fine, as generations of campers have used that setup with OK results.  But sometimes it ruins the batteries, especially if left hooked up to shore power for extensive lengths of time as in winter storage.  More sophisticated chargers like the Progressive Dynamics ones manage the charging cycle better and reduce the risk of boiling your batteries.

The addition of the 4400TAU module allows the Parallax converter used in PC motorhomes to monitor the battery temperature and adjust the charging voltage appropriately.

Ron- how did you remove the black panel on the stove  vent hood to install your voltmeter? I installed a 4 digit voltmeter directly above my converter  using a small plastic  project box.

You ask a good question.  I seem to recall lifting the left edge of the panel, then shift the entire panel to the left a little bit to release.  You can see some pictures of the panel disassembled HERE.  The pics support my cloudy memory.

I bought the volt meter module from China via Ebay.  It is also a clock and thermometer.  The bundled black jacket wire cable is the thermal-couple for the thermometer.  The two switches adjust the settings.

Ok we have 2 6 Volt batteries .... And they require the distilled water added once a month as always. And Jim did price the AGM  but no decision. The PC has Interstatae batteries so that is what Jim priced in hopes posts would be in same place  as what we have when we transfer to AGM. When we get home I will print the line so Jim can read everyone's comments. Thanks so very much. Nice to have PC friends who know so much. Regards Patricia (Henry J)
P S. It seems to me this set up is the kiss of death going in. Not what we are youst to at all. And a very primative set up. Might work ok for those who rarely plug in while sitting idle. guess I need to add this to the new owners list I made so he can have an update. I know we are not the first to encounter this monkey business I have seen it mentioned before...Well it's been plugged in for a year and rarely driven off the parking spot. Have not reached 8,000 miles yet... So why haven't we had problems till now. The old batteries must have a 1 year lifespan... Then they die a horrible death. Hmmm.

My Trojan batteries-6v, that came with our 2012-2552 are still going strong after 5-1/2 years. We never leave RV plugged into 110v unless we are camping or packing up to go. We have two solar panels and a monitoring system that keep the batteries charged while it is in storage for half the year. I fill the two batteries every 2 months and they take about 10 oz of distilled water each time. I never let the batteries go below 50% charge when we are traveling. I leave the switch on that allows the arrays to charge the Ford battery while in storage. That battery only requires 4 oz every 2 months.
 
We leave tomorrow for 4 months in FL, see my blog below.

Patricia,

Your profile says you live in Tampa.  Why would you keep your PC plugged in all the time?  Just plug in for a day once a month and all will be well with your house batteries.

About your chassis battery, I would disconnect it because of the residual drain from the chassis itself.  If you do nothing for it's own maintenance, the chassis battery could drain in a couple months, pending it's own health.

Just my thoughts about all that.

Battery life is extended by minimizing discharge. Batteries should be brought back to 100% state of charge as soon as possible.  The life of a battery is significantly shortened if taken below 50% charge.  Far worse is to allow the battery to completely run down.  Another major cause of premature failure is allowing the liquid level to drop below the top of the plates so it is critical to frequently check the level when being charged to prevent exposing the plates to air.

I had a Parallax converter/charger in a previous camper and it charged at 13.7 volts which is higher than typically recommended for long term charging.  I limited the time when connected to shore power.  I am not sure if Phoenix uses the same type converter.

On our Phoenix I ordered it with a Progressive Dynamics converter/charger which drops the charge voltage to 13.2 volts for long term storage which reduces the loss of battery liquid.  If your converter fails you may want to consider replacing it with a Progressive Dynamics unit. 

I would also suggest getting a volt meter to insure the battery is 12.6 volts or higher if the charger is disconnected.  A battery monitor such as Trimetric or Victron would be a better choice though more expensive.  These monitors allow one to keep a close check on actual charge level and how much energy has been removed from the battery though they are more expensive.

When not connected to shore power for long term storage it is important that there is no power drain which may require disconnecting the battery otherwise the battery will be prematurely discharged.

Hello Ron , you asked why we keep the  RV plugged in all the time. Well  we always have and the others which were 41 ft Allegro Bus, had more sophisticated battery charger monitor I am sure ... You could look at it and tell what it was doing and it had visible adjustments and knobs... AND we keep the air conditioning on at all times. No mildew, mold  or strange  melted things... Better cool than 120 degree's.
and I don't usually turn the refrig off unless I am defrosting and then only for a short time. Heat can do damage to things you carry and to the unit inside... We have 2 air conditioners. Even if I move it into a bldg which I can we keep ac on... There is always a level of heat except maybe tonight overnight.
So hope that explains we don't need to put antifreeze anywhere but the radiator but there are other considerations.
Thanks , maybe this gives you a different angle to view from too. regards, Patricia 

Ah, I understand now.  You have a "need" to run the a/c year round to protect the inside of your PC.  That makes sense.  Given you have 6V batteries already, then I do wonder if AGM batteries would be your solution.  I wonder if you could turn off your 12V system and just let the a/c run off 110V.  But I don't think your fridge will run under those settings.  Trial and error will provide your best answer.

Ron you are right about the fridge. I had an episode with the big Allegro Bus and the 12 v connection somewhere underneath was not working well or at all and no refrigerator for 3+ weeks... and it was a bear to find... no layouts and so took ages...I think Jim will order the AGM and see if this solves the issue for a while... he wants us to do our trip to Spokane and Ione, Washington to see son next Aug and end up at the Get together in Minnesota or where ever it is...Guess I will catch up on my miles since it is 2800 miles from home to get to Spokane and then do a cross back and then south again. Will see how we hold out. Old age holds surprises and some are not good. Jims heading to 86.... I'm still 39 going around my second trip. Regards, Patricia whose first car was a Henry J

Hello Ron , you asked why we keep the  RV plugged in all the time. Well  we always have and the others which were 41 ft Allegro Bus, had more sophisticated battery charger monitor I am sure ... You could look at it and tell what it was doing and it had visible adjustments and knobs... AND we keep the air conditioning on at all times. No mildew, mold  or strange  melted things... Better cool than 120 degree's.
and I don't usually turn the refrig off unless I am defrosting and then only for a short time. Heat can do damage to things you carry and to the unit inside... We have 2 air conditioners. Even if I move it into a bldg which I can we keep ac on... There is always a level of heat except maybe tonight overnight.
So hope that explains we don't need to put antifreeze anywhere but the radiator but there are other considerations.
Thanks , maybe this gives you a different angle to view from too. regards, Patricia 

You can disconnect the house batteries and put them on a small maintainer like a Battery Tender.  They will NOT cause battery water loss.   You only need to disconnect the negative cable.

http://products.batterytender.com/Chargers/Battery-Tender-4-Amp-Power-Tender-Selectable.html


Fridge wiil run from the converter/charger off the AC shorepower since you keep it plugged in all the time.