Battery...

[twiceblessed....nacole 433]

Here is the info, on our camper's battery.  I don't think it's a great one... but my real question is, do you think it will be sufficient to carry three items (total of 20 amps) for 8 hours?   If I'm reading the battery correctly, I think it will be.  But this is all still pretty new to me, so I wanted to double check.  If we end up doing more boondocking, I think we'll buy a new battery.

 

 

Exide Stowaway Deep Cycle Battery

Part # 24MDCST

500 MCA @ 32 F

400 CCA @ 0 F

140 RC mins

80Ah @ 20 Hr. Rate

[tim5055 120]

No, it won't.  I doubt there are many/any commercially available batteries that will carry 20 amps for 8 hours.

 

20 amps solid is a very high draw.

 

Check this out for an idea of how the calculations are made:  http://all-about-lead-acid-batteries.capnfatz.com/all-about-lead-acid-batteries/lead-acid-battery-fundamentals/what-are-amp-hours/

 

For a heavy draw you will need to be looking at dual 6v golf cart batteries.  Here is what I set up on my previous pop up http://www.title-3.com/Battery.htm

 

For a great tutorial on RV batteries and electrical suystems read this:  http://www.manmrk.net/tutorials/RV/12voltSideofLifePart1.htm

[twiceblessed....nacole 433]

Okay... thank you!  That link was very helpful as it explained that this battery "should" allow 4 amps for 20 hrs.  We definitely don't need 20 (I took a better look at what we have and I think it's closer to 8 amps), but either way... our current battery will not work.

 

With this in mind... does anyone have any suggestions, on a solid RV battery?  Currently, we only have room for one battery.

[arthuruscg 34]

What are you trying to power? It might work out better to reduce your power consumption rather then supply.

[twiceblessed....nacole 433]

What are you trying to power? It might work out better to reduce your power consumption rather then supply.

 

We'll have to run both the fridge and the a cpap machine.... so there is really nothing that we can reduce.

[tim5055 120]

Is this an RV fridge?  If so it should run off LP gas.  If not you will never be able to run a refrigerator off a battery.  They just consume too much power.

 

Also, is the cpap 12v or 110v using an inverter?  If using an inverter they are not 100% efficient so you will have more loss in the inverter.

[twiceblessed....nacole 433]

Is this an RV fridge?  If so it should run off LP gas.  If not you will never be able to run a refrigerator off a battery.  They just consume too much power.

 

Also, is the cpap 12v or 110v using an inverter?  If using an inverter they are not 100% efficient so you will have more loss in the inverter.

 

Fridge runs off LP, which (from websites I read) takes 1.5 - 2 amps/hr.   The cpap, I had planned on using an inverter, but I am going to run out and measure now... to see if an adapter will work (it only has a 6 ft cord and the plug is far from the bed, so I don't know).  We're going to use his old cpap which only pulls 4.16 amps on 12v.    So we're at 6.5A.

[CCIntrigue...aka Gwen 547]

NaCole, remember that neither one will be running continuously for the 24 hours.

 

The fridge will only need battery power to run the electronic ignition.  And if you keep the doors shut, you can turn it off for 8 hours overnight (unless you're camping in extreme heat).  I'd put a few blocks of ice in the fridge just as insurance.  

[twiceblessed....nacole 433]

NaCole, remember that neither one will be running continuously for the 24 hours.

 

The fridge will only need battery power to run the electronic ignition.  And if you keep the doors shut, you can turn it off for 8 hours overnight (unless you're camping in extreme heat).  I'd put a few blocks of ice in the fridge just as insurance.  

 

Thanks Gwen... that's a good thought! 

[mouseketab.....Carol 1,261]

I just bought a brand new battery, Look up Blue Top Optima. For a single battery, from what I understand very reliable, and can stand the discharge from boondocking better than your standard Green top battery wet cell battery.

[LONE-STAR 370]

I just bought a brand new battery, Look up Blue Top Optima. For a single battery, from what I understand very reliable, and can stand the discharge from boondocking better than your standard Green top battery wet cell battery.

Optima is the king of taking abuse and keep working in a battery. We use them at work on most of our equipment. I have a red top optima in my golf cart that is over 10 years old and been ran dead more times then I can count and still works fine.

[swimmarz 72]

look at almost any AGM battery, that is an Absorbed glass mat, that is they style of optomia.

they are typically of a better build quality and dictate a higher price

I have a Duralast AGM in my TV that i rarely drive( 6,000 miles in 2.5 years) and its never had a problem starting it event after sittings for a month or more.

when my trailer battery goes Ill change over to an AGM for that as well 

 

I believe with any battery if you properly maintain them they will last a while, so invest in a good trickle charger to keep it topped off when not in use

I have a battery tender jr for the trailer, but have use the same unit on my Lawn tractor and that battery was 5 years old before it finally went

[twiceblessed....nacole 433]

I just bought a brand new battery, Look up Blue Top Optima. For a single battery, from what I understand very reliable, and can stand the discharge from boondocking better than your standard Green top battery wet cell battery.

 

 

Optima is the king of taking abuse and keep working in a battery. We use them at work on most of our equipment. I have a red top optima in my golf cart that is over 10 years old and been ran dead more times then I can count and still works fine.

 

 

They look different and are more expensive... can you help me understand the difference?  Tom is not a nature camper, so our boondocking will be limited to pulling over at a Cracker Barrel for a night (using the battery maybe 8 hours) 2 -4 times per year.   With that in mind, do we need to spend the money on a more expensive battery?  I found an interstate that should fit our needs for $121.   Thoughts??

[swimmarz 72]

they are different, they are an AGM or absorbed glass mat, Optomia is a premium brand but you can get AGM in other brands for cheaper.

Personally I switched to AGM in the Cars and like it, they seem to hold up longer for some reason

 

 

 

(AGM) ABSORBED ELECTROLYTE

Advantages

• Ideal for standby or back-up applications
• Higher charge and discharge currents
• Totally maintenance-free
• Air transportable
• Spill proof/ Leak proof
• Minimal corrosion thus physically compatible with sensitive electronic equipment
• Installs upright or on side
• Lower cost than gel cell batteries
• Very low to no gassing (unless overcharged)
• Excellent for starting and stationary applications
• Superior for shorter duration/higher discharges

Disadvantages

• ½ the cycle life of Gel or flooded Wet Cell in deep cycle applications
• Charge voltage must be limited (14.1 to 14.4 volts maximum at 68°F )
• Voltage-regulated chargers must be used
• Water cannot be replaced if continually overcharged
  
  

  WET CELL (FLOODED ELECTROLYTE)

  Advantages

  • Lowest initial cost
  • Water can be added (if accessible)
  • Excellent for higher current applications
  • Certain designs are good for deep cycle applications
  • Replacements readily available

  Disadvantages

  • Spillable
  • Operates upright only
  • Emits corrosive Gases and thus cannot be installed near sensitive electronic equipment
  • Cannot be installed near sensitive electronic equipment
  • Maintenance required (if accessible)

[mouseketab.....Carol 1,261]

I got the Optima AGM because of the way I use the camper. On our longer trips, we frequently stop overnight at hotels. My DH is less of a nature lover than yours, and doesn't even like to overnight in the camper at a campground. He is really only comfortable once I've fully set up. So we do our overnight stops at hotels and run our 2-way fridge overnight on the battery (slightly different model than the 3-way fridges, and only uses electric or 12V, but more efficiently than 3-way fridges). Then the next morning we have a shorter drive to our destination, so the battery has less time to charge on the road.

 

I then need battery power to run the power mover once arriving. The AGM I got has a larger capacity, slower drain, and can also stand up better to repeated draining.

 

If you are "parking" overnight and have CPAP use, then an AGM will be better than a wet cell battery.

 

I found my Optima Blue Top on ebay for almost $100 less than the prices locally. I had to charge it with an offline battery charger once I received it, but after that, I installed it in the camper, and it worked perfectly.

 

http://www.ebay.com/itm/181884248685?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[rtguy007 74]

Nacole,

 

You will probably get a ton of good advise on here but I wanted to give you my experiences. I have dealt with batteries for a while and the biggest key is to getting a good long lasting battery is proper maintenance. It really isn't hard but it also depends on the type of battery you get. The different type of batteries (Flooded Lead Acid, AGM, and Gel) all have different recharging requirements. Depending on your onboard charger, you probably won't be able to use it to charge a Gel battery. It seems that from my research that there is a 50/50 chance your onboard charger will properly handle an AGM without either drying the internal cells out or repeated under voltage charges (reducing the amp hour capacity). Personally I would stick with a flooded lead acid battery. The maintenance is really not that hard and only needs to be done once every month or so (at about 10 minutes worth of work total).

 

If you are hunting for a new battery, if it doesn't have an amp hour rating on it, then it is not a true deep cycle. If it has a reserve capacity rating it is a hybrid deep cycle/conventional battery. Either will work but a true deep cycle really is better for RV's when possible. Never use an automotive battery. Based off of the model number you put in here, you have a true deep cycle. I have the same battery except I put a second one on my RV as well because we dry camp at a few places and the extra battery power at night helps with the fantastic fans we run when it is hot.

 

If you are going to be doing any dry camping, you are going to want a higher capacity battery. There are some options with this as well. You will hear to grab 2 golf cart batteries and add an extra box to your trailer if you can do that. I am not a fan of the golf cart battery option because if you lose a cell in one of the batteries you do not have 12v. On top of that, you will have to replace both (as you should with any dual battery setup). If you had a pair of the same battery you have now, you will be able to get a lot more "run time" than what you are used to. If your existing battery was properly maintained, you will get double the run time on it. Another option is to remove your group 24 battery that you have now and the box and add a group 31 battery/box (only if you need a little more run time before charges).

 

So I see 3 options.

1) Expand to 2 6v golf cart batteries and run them in series (giving you 12v and around 180-200 ah of capacity with a good set of batteries)

2) Keep your existing 12v that is rated at 80 ah of capacity and add a second one to it if you have space to (giving you 160 ah of capacity)

3) Replace your existing 12v group 24 battery with a 12v group 31 battery (giving you 115 ah with one battery)

 

I went with option 2 using the same battery that you have. A 3 amp draw will run for 8 hours but the batteries were pretty low in the morning after we woke up. Every day we ran them down that low we recharged them fully when we were allowed to run our generator (and using a real battery charger and not the one on the generator).

 

I could go on for hours about batteries and selection......with that said....MAINTENANCE  :D

 

You have to properly maintain a battery. This is the reason I say stick with standard lead acid deep cells (of the flooded type) and not an AGM or Gel. The different types of batteries require you charge them to a specific level to be full. Here is the kicker, all 3 types require a different max voltage for charging. To make it worse, the charger in your camper is probably keeping you from fully charging your batteries (regardless of what the monitor in the unit says). For standard lead acid batteries, they have to reach a minimum of 14.4v during charging. Most RV chargers only charge to 13.8v. Even though that is over 12v the problem is that under charging the battery will get you into a situation where your batteries only last a year or two at the most. A properly charged battery can last you over 5 years if maintained correctly.

 

Undercharged batteries or "charge depleted" batteries have the same effect. There is a bunch of technical stuff that I could explain but do not let your battery fall under exactly 12v charge EVER. Realistically never under 12.3v but that is a good safe point to know that you are not harming the battery itself. Both undercharged and not fully charged batteries have the same impact....loss of longevity.

 

Notice the only thing here is proper battery voltage. That is 90% of the challenge to proper battery maintenance. The last 10% is making sure you keep those flooded cells properly filled (if it is not a maintenance free battery). Once a month or so, pop the vent cap off of each cell bank, make sure that the water/acid level is not lower than the top of the metal plates. It can be over but not under. I keep mine with plenty of "extra" water in it but not to the point where it is coming out of the top of the vent hole. Just fill the cell up with DISTILLED water and you are good to go. I let one of my cells fall under the top of the plates and that battery is working but no where near where it was. It doesn't hold a charge as well as it used to.

 

Using a battery tender is a good option to keep a battery charged but never use one for charging. I would recommend a good charger like the NOCO 15000 (which is what I have). I also have a deltran battery tender plus for my lawn mower and atv batteries and it works well to keep them topped off. Never skimp on a battery charger as it will save you money in the long run.

 

Personally, i don't use the onboard charger/converter to charge my batteries, i let it maintain them but deep cycle charges are recharged with the NOCO.

 

This is the site I learned the most about batteries and charging (http://www.batterystuff.com/kb/articles/battery-articles/battery-basics.html). If you read up there and then apply that info to your RV batteries, you will be good to go and enjoy those long lasting batteries.

 

OK I am getting off of my soap box.  :bravo:

 

As I walk away from my soap box, don't forget those small things that always pull on your batteries (even in storage if you don't disconnect them). Those are:

 

Stereo, clocks, CO2 and Smoke detectors, any accessories you may have added. Add the values of these running to whatever you will run when camping to get a realistic understanding of your power draw.

[rtguy007 74]

Also, if you get into dry camping a lot, look for a good inverter generator for running your AC if you absolutely must have it. They are quiet and lighter than a conventional generator, use less gas, and give you the ability to quickly recharge those batteries (unlike small solar units). My sister uses a Champion 3100 inverter generator and it will run her AC and TV with no problems while the fridge is on gas. I have a pair of 2000's with a pairing cable to do the same thing. Both setups work well. I know honda and yamaha make great units as well.

 

OK I am really done now. Let me know if you have any questions on dry camping. I could go on and on for hours since we have done it for years as a family. I could give you the "tips and tricks" we have learned.

[twiceblessed....nacole 433]

Thank you!  That's a lot of information, and I feel a bit overwhelmed (I mean, I didn't even know that you needed to "maintain" your battery... except I remember Carol (I think) telling me last winter to pull the battery off our hybrid after we winterized the RV.  I did that and stored it in our garage, which is insulated, wrapped in a Uhaul blanket).  So much to learn these first couple of years.

 

Really appreciate the advise I get from my Fiends... :)

[arthuruscg 34]

There are a decent number of people on popupportal.com with cpap machines, the consensus is to not use the humidifier function and to get a 12v power cord for it.  12v DC to 120V AC converters are not that efficient if your machine has a large power plug it will be stepping the power back to DC (voltage varies though). So with converters you are trowing away power 2 times. Converting from 12V DC to another DC V is very efficient and a lot of adaptors can be found at Radio shack or online.

[twiceblessed....nacole 433]

There are a decent number of people on popupportal.com with cpap machines, the consensus is to not use the humidifier function and to get a 12v power cord for it.  12v DC to 120V AC converters are not that efficient if your machine has a large power plug it will be stepping the power back to DC (voltage varies though). So with converters you are trowing away power 2 times. Converting from 12V DC to another DC V is very efficient and a lot of adaptors can be found at Radio shack or online.

 

Yep... that's what we did.  I found a 12V power cord that was long enough to work :)