How much Battery do I need?

I have the camper home  HORRAY!!  I have a power source for it, but my cord is 30 ft and I need 40 ft.  The extension is on order.  In the meantime, I run on battery.  When we got home, the landing gear was fine, all 3 slides out just fine, but lights were a bit dim.  The camper was 6 - 8 inches off level side to side, but I did not have the right lumber to level.

Today, I was ready with leveling planks (2 X 12).  The first slide came in okay.  The second came in about 2 inches, then stalled.  When I attempted to retract the third slide, the SECOND slide tried to move!!  When I tried to lift the camper with the landing gear while plugged into the truck, it moved s l o w l y.  Without the truck, the motor stalled.

I connect a charger, and the landing gear functioned as expected, and both slides retracted normally.  Lights in the camper are normal, then dim, I assume as the charger cycles.

I assume the battery is toast.  It is 4 years old, NOT deep cycle.

My research shows I can get a deep cycle 100 AH 12V battery for about $100  or  a 200 AH 6V battery for the same price.  Granted, I will need 2  6V batteries.

For the short term, I expect to camp with electric available.  Long term, who knows!

Is the 100 AH - 50 usable AH sufficient, or do I need to spring for 4 times the AH for only 2 timed the price?  More research will follow after I identify what I need.

For your short term needs, just get another 12V 100AH battery.  I'm assuming you don't have an inverter to power TV, microwave, etc.  In the future if you start to dry camp or boondock, you will want more batteries and probably an inverter.  Also significant research info about how to keep the batteries charged.

Keep in mind trying to keep the trailer battery charged only by driving or being connected to the truck does a very poor job of charging the battery.  The 12V power wire in the harness connecting the truck to the trailer is too light of weight and much to long a distance from the alternator to the trailer battery to be able to put much power back in the battery.  If you just use the trailer lights for 3-4 hours one night and little or no furnace operation, driving 4-8 hours the next day will probably keep your battery charged.  Running the furnace (the blower pulls lots of power) a lot uses quite a bit of battery.

An additional note.  Two 6 volt 200AH batteries will give you 200AH at 12V.  Batteries in series add the voltage (6V x 2 = 12)  Batteries in parallel add the amperage.

If you are interested in more info about RV electrical systems, batteries and solar work, here is are links to some very good info:
http://www.marxrv.com/12volt/12volt.htm
http://www.marxrv.com/12volt/12volta.htm

Thanks, Al.  I forgot the "voltage effect"  I'll go 12V deep cycle for now.

I am running 3 group 31 batteries and can go about a week, however, I don't have a TV and very seldom use the microwave using an inverter.

Lot's of fun with a new to you RV huh?

Is there water in the battery?

What is you power source? 30 amp or 50 amp and who wired it?

Why not use a temporary extension cord of the common 16 gauge outdoor type?  It will deliver 10-12 amps, which is plenty for the onboard converter/charger. Just don't use the a/c, microwave, etc until you get the higher amp cord.

If you think you want a 200 AH battery system, the pair of 6v's is a cost effective way to do that.  However, you won't get a 100AH true deep cycle 12v for $100 either. You are probably looking at $200+ for that. You may be able to get a halfway decent 12v AGM sort-of deep cycle for around $160, though. It's not a bad compromise on price/performance.

Arch:  I am having lots  of fun!  The camper is 50A and has a 30 ft power cord.  I wired the outdoor 70A RV box, but it is 40 ft from the camper power plug.  Extension should arrive tomorrow.

AD:  I ordered the cord from RV Upgrades yesterday.  Best price. Standard 3 -5 day delivery.  Actual 2 day delivery.

Gary:  I have a 12 ga 120V cord feeding a battery charger.  How would I feed the camper from this?  Buy a dog bone?  With the real cord due by tomorrow evening, I'll pass for now, but it never came to mind as a solution.  Thanks for the idea.

The reason I asked who wired the RV outlet is because even licensed electricians get it wrong and put 220 volts on the lines. 

I don't want to sound condescending but are you knowledgeable about how a 50 amp outlet should be wired?  If it's wrong you will destroy everything.

Arch Hoagland said:

The reason I asked who wired the RV outlet is because even licensed electricians get it wrong and put 220 volts on the lines. 

I don't want to sound condescending but are you knowledgeable about how a 50 amp outlet should be wired?  If it's wrong you will destroy everything.

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Now you have me wondering...  My coach says it has a 50 amp 220 VAC service.  The shore power I set up at home is 50 amp 220 VAC and everything is fine.  Are you saying that Standard 50 amp plugs are just 110 VAC like the 30 amp plugs?

I am an electrician and I have worked on every thing from 4160 3 phase down to 5 volt DC electronics.

"CX"

Fifty Amp RV's do use 220Vac but as two banks of 110Vac. The problem usually found is that a 30A rv plug looks very much like a washer/welder outlet and electricians often wire them for 220. That will destroy a number of things in the rv.

Ernie

A 50 amp supply for an RV is 240 volts. It's exactly the same a kitchen range on a house. People here argue a moot point about not being 240 volts, but (2) 110 volt legs. That's essentially useless information, as the 240 volts to your kitchen range is (2) 110 volt legs, but it's still a 240 volt service.

Where the real issue comes in is for 30 amp service for RV's. RV's use 30 amp, 120 volt service, but people have wired the 30 amp service for 240 volts like a dryer or welder, and fried equipment in the RV.

Kdbgoat is exactly right.

I wired it myself, and must have done it right.  I got my 50A extension cord today and plugged the camper in, and nothing went POP - yet.  Good to be back on shore power!

I also got a new battery today.  Group 27 12V.  Got propane, too.  Now the furnace works!!

Now, all I have left is figuring out the TV wiring, fix the Sleep Number bed, edge some frayed carpet, install levels, make a stinky slinky storage pipe, check the emergency exit window, make a fan knob extender, install a Progressive EMS, ............

To be specific about some things about a RV 50 amp service, since there are lots of words and terms flying around in this topic.

--  50 amp RV service is really 100 amps to the RV.  50 amps on each leg of the 120V wires, L1 & L2. 
--  The 50amp service is designed to have two 120V AC legs which are 180 degrees out of phase with each other.  The ground return wire is only designed to handle 50amps.  If by chance a single phase 120 line at 100 amps (or 70 amps as mentioned earlier) that would overload and possibly overheat the ground return wire.  Of course to get that kind of load you would have to run both air conditioners, the microwave, water heater on elect, and maybe a couple of other items.
--  50 amp RV's only have 120V devices. While you measure 240V between the two hot legs on the 50amp service, the two hot legs each go to a separate 50 amp C/B in the RV, each powering about 1/2 of the RV.  Each 50 amp CB services a string of 15 or 20 amp C/B's  To be accurate there are a very few high end rigs with 240V devices but they are few and far between.

AStravelers said:

To be specific about some things about a RV 50 amp service, since there are lots of words and terms flying around in this topic.

--  50 amp RV service is really 100 amps to the RV.  50 amps on each leg of the 120V wires, L1 & L2. 
--  The 50amp service is designed to have two 120V AC legs which are 180 degrees out of phase with each other.  The ground return wire is only designed to handle 50amps.  If by chance a single phase 120 line at 100 amps (or 70 amps as mentioned earlier) that would overload and possibly overheat the ground return wire.  Of course to get that kind of load you would have to run both air conditioners, the microwave, water heater on elect, and maybe a couple of other items.
--  50 amp RV's only have 120V devices. While you measure 240V between the two hot legs on the 50amp service, the two hot legs each go to a separate 50 amp C/B in the RV, each powering about 1/2 of the RV.  Each 50 amp CB services a string of 15 or 20 amp C/B's  To be accurate there are a very few high end rigs with 240V devices but they are few and far between.

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Good explanation!!

Good explanation. Except the return is the "neutral", which connects to the ground at the server panel.

To be accurate there are a very few high end rigs with 240V devices but they are few and far between.

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Used to be rare, but getting more common all the time. More and more mid & upper tier coaches are installing some 240v appliances, mostly clothes dryers and cooktops. All-electric models often have load centers that support 240v circuits & breakers.