Battery disconnect

rvpezzano · 01-02-2014, 01:41 PM

When plugged in at a campground for an extended stay(a month or more), can you hit the battery disconnect switch to off to prevent over charging the house batteries? I have a 2008 Georgetown.

KMP44 · 01-02-2014, 01:50 PM

Yes - I've done it at home with the TT plugged in. Lights/slide motors still worked fine with 12v from the converter. Not 100% sure if there is any possible down side to do this, but it does work. On my "someday" list is better quality converter to avoid this and avoid worrying about whether I'm doing the right thing to maximize battery life.

alparmer · 01-02-2014, 05:44 PM

I need to verify this, but I would think the battery charger/maintainer in the coach is smart enough to prevent overcharging. Basically, it charges the battery at a higher amperage until a certain voltage then it switches to a trickle charge as needed. Either way, lead acid batteries are pretty tough and can handle overcharging.

The one thing that really hurts their longevity is running low on acid (distilled water) as the lead plates need to be immersed in it at all times. Now, overcharging could cause the acid to evaporate especially in hot weather, but it would have to be high amperage for prolonged times. That's why the newer AGM type of batteries are better since the acid never escapes the enclosure. On the other hand, under and over charging is a serious problem with lithium ion and polymer batteries. I've seen a lithium polymer battery blow up due to a bad charger.

I've always left our campers plugged into shore power with batteries connected without any problems. If you want to disconnect them and they will be disconnected for a long time, it's best to buy a trickle charger and keep them maintained. I used to have to change the battery in my lawn tractor just about every year until I bought a solar charger and have had the same battery for three years now. Not the cheap ones that always put out a voltage, but one with an actual controller board that reads battery voltage and adjusts charge accordingly.

Iggy · 01-02-2014, 06:14 PM

Quote:

Originally Posted by rvpezzano

When plugged in at a campground for an extended stay(a month or more), can you hit the battery disconnect switch to off to prevent over charging the house batteries? I have a 2008 Georgetown.

Why do you think your batteries will be over charged?
Why would you do this if you have good batteries and a intelligent battery charger?
If you don't all you will be doing is running off of the battery charger itself and will never charge the batteries.
If you do this it defeats the purpose of the whole system.

rvpezzano · 01-02-2014, 07:01 PM

When I first got the Motorhome, I left it plugged in all the time. Summer and winter. Then I wasn't checking the batteries regularly. They were low on water. I added distiller water but one of them had a bad cell. They were about 3 1/2 years old. Just lately when we spent 2 months in Washington,I turn the disconnect switch off. Before we left I turned it back on. That was mid Sept. I just check the water and it was fine. I know what your saying about the coach's charger but I don't know what kind of charger it is or if it is the stepped one.

Mikegjax · 01-02-2014, 07:21 PM

If you want to keep your batteries on a charger, I would recommend the "Battery Tender Plus" it is a 4 stage tender and works on AGM, gel and regular lead acid. Many chargers have a higher floating amperage and are not good for AGMs. I leave my batteries on a tender whenever I am home and not on shore pwr. Really increases the life of the battery and keeps them at their peak based on my experience. Still need to check water levels where appropriate.

Trempert · 01-02-2014, 10:25 PM

Quote:

Originally Posted by rvpezzano

When plugged in at a campground for an extended stay(a month or more), can you hit the battery disconnect switch to off to prevent over charging the house batteries? I have a 2008 Georgetown.

I would not do this for these reasons:
1. If the batteries are overcharging, it is because one or both batteries have an internal short.
2. The battery charger cannot overcharge a good battery because the resistance of the battery approaches infinity as it becomes fully charged.
3. The converter has an amperage limit (I don't recall what it is) and it is not sufficient to run large ampere drain items such as slides/levelers.
4. Running large ampere items with just the converter will cause the voltage to drop and you'll start blowing fuses and throwing circuit breakers
5. Large voltage drops and then the subsequent surge when you remove the load can damage sensitive electronics. Batteries (if connected) will absorb the surge.
6. A discharged battery may freeze as the electrolyte level will be low.

If your batteries are bad, replace the batteries as that will be the end result anyway.

alparmer · 01-03-2014, 07:54 AM

Quote:

Originally Posted by Trempert

I would not do this for these reasons:
1. If the batteries are overcharging, it is because one or both batteries have an internal short.
2. The battery charger cannot overcharge a good battery because the resistance of the battery approaches infinity as it becomes fully charged.
3. The converter has an amperage limit (I don't recall what it is) and it is not sufficient to run large ampere drain items such as slides/levelers.
4. Running large ampere items with just the converter will cause the voltage to drop and you'll start blowing fuses and throwing circuit breakers
5. Large voltage drops and then the subsequent surge when you remove the load can damage sensitive electronics. Batteries (if connected) will absorb the surge.
6. A discharged battery may freeze as the electrolyte level will be low.

If your batteries are bad, replace the batteries as that will be the end result anyway.

+1 the batteries act as large capacitors.

Back when I was into old Jeeps I always used an Analog Load Battery Tester. It would tell you if a battery is weak due to a bad cell and save you headaches down the road.

alparmer · 01-03-2014, 07:59 AM

More on the battery tester. If you get the analog type the battery has to have a 75% charge or more for the tester to be accurate. If you believe your batteries are not charging properly, I would get a digital load tester. The analog ones go for about 30 bucks whereas the digital ones go for about 50.

BillMFl · 01-09-2014, 10:25 AM

I am sorry to say that both Georgetown MHs I have owned will "boil" the batteries because of over charging if shore power is on for an extended time and no major demand is being used. The two solutions are a more sensitive charging system (battery tender, etc) or systematically turning off shore power when the batteries are at full charge and the coach systems are not being used.

BigTJohn · 01-09-2014, 11:33 AM

If that is the case with the Georgetown MH, I would be looking to FR to change out the system (if in warranty) otherwise, just do it yourself. A quality, not necessarily an expensive, smart charger will handle all your charging and house functions plus keep your batteries in top condition. Still, you HAVE to do a little monitoring of your own, i.e. checking on battery water (the acid never evaporates only H2O), terminals, general cleanliness of the electrical system, stuff like that.

Trempert · 01-18-2014, 04:32 PM

Quote:

Originally Posted by BillMFl

I am sorry to say that both Georgetown MHs I have owned will "boil" the batteries because of over charging if shore power is on for an extended time and no major demand is being used. The two solutions are a more sensitive charging system (battery tender, etc) or systematically turning off shore power when the batteries are at full charge and the coach systems are not being used.

I understand why you would think that because that is exactly what my dealer convinced me of when I kept having trouble. Because I was still under warranty, I proceeded to call the converter company (can't remember the name) to tell them that I expected them to replace the unit for free for a unit that would properly charge the batteries. They said it wasn't the converter and gave me all the reasons I have in the string above. I then called Forest River directly and they said they would look into it. My dealer got a call and they replaced both batteries for free. Since then I never have to worry anymore (3 years) and never disconnect the battery charger. I'm happy, happy, happy. You DO need to check the water level every couple months.

Railroadman · 01-26-2014, 05:29 PM

RV is in storage, when I went to check I had to start the coach before battery disconnect would come on any help

Ford Idaho · 01-26-2014, 05:59 PM

Quote:

Originally Posted by Railroadman

RV is in storage, when I went to check I had to start the coach before battery disconnect would come on any help

RV model and year?

Railroadman · 01-26-2014, 07:04 PM

Georgetown 37'8"

bubbles · 01-26-2014, 08:31 PM

Your battery disconnect switch operates a latching relay to disconnect and connect your battery to the battery bus. A latching relay will actuate in one direction (disconnect battery) when the switch is thrown and actuate in the opposite direction (connect battery) when the same switch is thrown in the opposite direction. The relay coil 12v input switches with the relay actuation to accomplish this. It sounds as though your batteries were to low (minimum relay coil power required) to actuate the relay.

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