Need help with specs

[LadyWindrider]

At 20 degrees in the wind, your furnace runs about 50% of the time. One night may be all, especially if the furnace starts running at 7:00 p.m., and doesn't stop till 9:00 a.m. A monitor will allow you to monitor your situation only. I'm sorry, not trying to imply anything, just trying to understand. I have an engineering mind, and think like one. Each of us use power differently, and you'll have to figure out your own, based on trailer, insulation, furnace, water pump, lights, usage. What I can get by with, might freeze you. Most getting two days or more running the furnace, don't have a small child to keep warm, and have it set on 60 or lower. Good luck. By the way, for my money, get a volt meter, and when the battery reads 12 volts, recharge. Much cheaper than a monitor panel, but then I'm thrifty that way.

[NWJeeper]

Originally Posted by windrider

By the way, for my money, get a volt meter, and when the battery reads 12 volts, recharge. Much cheaper than a monitor panel, but then I'm thrifty that way.

The problem with a volt meter is the same as the monitor panel that comes with RVs they are reading voltage only and that is highly inaccurate unless the battery has not been used or charged for a period of time. If you were to connect a volt meter only to the battery and watch the voltage when you start the furnace you will see it drop noticeably, it will come back up when the furnace is turned off and shuts down. This in no way is an accurate picture of the amount of life left in the battery bank. Battery monitors need to have a shunt installed in-line with the negative cable on the bank and they keep track of the amperage which is coming into and flowing out of the bank. Amperage is the only true measure of the battery capacity and how much time may be left in it before it needs to be recharged. Of course none of this is pertinent to anyone who uses hookups all the time, the problem is moot at that point.

[Robs]

Battery is only fully charged at 13.6V

[Robs]

The WFCO series of 3-stage switch mode power converter are fully automatic. The converter senses which mode it needs to be in by checking the condition of the batteries.

The three modes include:

Absorption Mode:
During this mode the converter output is at 13.6 VDC range. This is the mode that the converter will function at normally. This mode provides the 12 VDC and the current required by the RV.


Bulk Mode:
When the converter senses that the battery voltage is less than 13.2 VDC the converter will automatically go into the Bulk Mode.


Float Mode:
If the RV is not being used for a period of time and the shore power has been left plugged in, the converter will automatically go in to float mode. The converter senses if there has been any demand. If there is no activity for a period the converter will automatically go into float mode. When the converter senses a demand by turning on lights the converter automatically goes into buck mode and returns to absorption mode.

[NWJeeper]

Originally Posted by Robs

Battery is only fully charged at 13.6V

Thanks Rob. Actually batteries need a periodic equalization charge at 14.4 volts or more to be fully charged and conditioned but this has been beatten to death in another thread here before.

[MtnGuy]

The bulk mode of the Wfco 3 stage charger is between 14.1 to 14.4 volts.

[rsl]

Thanks for all the help everybody, I think I am not going to chance becomeing an icecile while boon docking. I am looking into the pricing of 2 -6 volt golf cart batteries and also a 2nd deep cycle battery, I want to make sure I have enough juice to get me through a whole night of no generator with heat. I am also going to get the Tirmetric 20225-RV battery monitoring system.

[rsl]

OK so i am looking at either adding a second battrey or switching over to 2 6 volt golf cart batteries (cost vs value dependent) I currently have a Interstate HD24-DP Marine/RV deep cycle battery, i am not sure how many amp hours the battery is the only thing I see on it is 405 cca and 505 mca??? The other issue I have is, is the battery is in an enclosed plastic container (drain hole at bottom and vent tube vented to exterior at top)(interior dimesions are 7 1/4" wide x 12 1/2" long x by about 10 1/2" high). I dont want to drill another hole in the bottom of comparment if I can help it and not sure how i would hook 2nd vent tube to exsisting one. Is there a double battery box that would handle either 2 12 volt or 6 volt batteris and if not will my exsisting box accomidate a 6 volt battery? And also are there any disadvantages of getting AGM or gel cell batteries (figuring not have to worry about topping off water).

[NWJeeper]

Originally Posted by rsl

OK so i am looking at either adding a second battrey or switching over to 2 6 volt golf cart batteries (cost vs value dependent) I currently have a Interstate HD24-DP Marine/RV deep cycle battery, i am not sure how many amp hours the battery is the only thing I see on it is 405 cca and 505 mca??? The other issue I have is, is the battery is in an enclosed plastic container (drain hole at bottom and vent tube vented to exterior at top)(interior dimesions are 7 1/4" wide x 12 1/2" long x by about 10 1/2" high). I dont want to drill another hole in the bottom of comparment if I can help it and not sure how i would hook 2nd vent tube to exsisting one. Is there a double battery box that would handle either 2 12 volt or 6 volt batteris and if not will my exsisting box accomidate a 6 volt battery? And also are there any disadvantages of getting AGM or gel cell batteries (figuring not have to worry about topping off water).

There are lots of pros and cons to consider. Your present battery with the MCA and CCA on it are useless numbers as it relates to an RV system. Those are engine starting numbers and proof that your battery is not a true deep cycle. None of the starting/deep cycle batteries are. If you can fit 2 6volt batteries you are much better to do so, but many rigs don't lend themselves well to doing it, space wise. You may have to come up with a custom setup to do it and or get creative. AGM and Gel cell batteries can be mounted in any position even on their sides and true you don't have to worry about watering them but they do have different charging needs that are different than led acid batteries, they are also much more expensive on an amp hour/dollar basis.

I think only you can really answer your own questions here concerning your own rig and where you can mount batteries. They don't have to be right next to each other either but you will have to run a little heavier cable between them if they are separated. Welding cable works best as it is very flexible. Just remember you shouldn't mix battery types and sizes. If you plan on doing a lot of dry camping consider investing in more energy efficient lighting too. Either flourescent or LED.

[MtnGuy]

Originally Posted by rsl

I currently have a Interstate HD24-DP Marine/RV deep cycle battery, i am not sure how many amp hours the battery is the only thing I see on it is 405 cca and 505 mca???

Here are the stats on the HP-24-DP, as well as the DCM-24 that has more amp-hours.

http://www.interstatebatteries.com/c...o/marine_f.asp

[rsl]

space is not a cooncern as there is plenty of room in the front comparment to fit the batteries, just the battery box size and venting is the concern. Also if the CCA and MCA are not numbers to use, how can i compare deep cycle batteries?

[NWJeeper]

Originally Posted by rsl

space is not a cooncern as there is plenty of room in the front comparment to fit the batteries, just the battery box size and venting is the concern. Also if the CCA and MCA are not numbers to use, how can i compare deep cycle batteries?

CCA and MCA refer to how much power can be delivered in a very short amount of time "burst" to start an engine and have no relevance to RV use. True deep cycle batteries are not used to start engines and therefore are rated in Amp Hours. You want the highest Amp Hour rated battery you can afford.

A typical single Group 24 or 27 battery supplied with RVs will typically have between 70-105 amp hours of storage. Compare to 2 Trojan T-125 6V batteries with 240amp hours. More than double.

If you haven't yet visited the 12 Volt Side Of Life you really should as it will answer a lot of your questions in detail.

[rsl]

ok i visted the page, and understand what it is saying however i need a baseline to go from, is there a "amp hour" rating on my curent battery? I want to make sure I at least double it. If it happens to be one of those "bigger" deep cycle batteries with 120 amp hours then it is not worth the money to me to install to 2 regular deep cycle batteries and only gain 25 amp hours

[MtnGuy]

I think this is the way the chart reads.

The HD24-DP will supply 11.6 amps for 5 hours.

The DCM-24 will supply 16.4 amps for 5 hours.

There is no true amp hour reading on the chart. 11.6 x 5 hours equals 58 amps per hour, and 16.4 x 5 hours equals 82 amps per hours. But if you notice, the further out you go, the total decreases with the 15 and 25 hour columns. So I figure that a true amp hour for the batteries should be above the multiplied results of the 5 hour column.....if that makes sense. A true amp hour for the DCM is above 82. The chart is probably a little more realistic than just showing just amp hours.......are you going to use 82 amps all up in 1 hours......probably not........it is going to be over time.

[rsl]

Ampere hours (Ah)
Tested at 80 degrees Fahrenheit. It is the amount of current (in amps) a battery can deliver, multiplied by the amount of hours, without falling below 1.75 volts per cell (10.5 volts on a 12-volt). Most marine/RV-deep cycle batteries are rated on a 20-hour discharge rate. Example: a 100 Ah battery can deliver 5 amps for 20 hours (amps x hours = Ah).



So based on this, if I am understanding the math right I have a 58 Amp/Hour Battery?

[NWJeeper]

So based on this, if I am understanding the math right I have a 58 Amp/Hour Battery?

Basically yes but I would be surprised if it is that low, I would bet it's closer to 70 but remember that the numbers are effected by temperature too.

Also consider that 6volt golf cart batteries (Trojan T105, 125, 145 and others) are true deep cycle batteries and can better withstand a deep discharge and the resultant re-charge cycle than a starting/deep cycle battery. This is the reason they are so widely used in RVs for dry camping.

[MtnGuy]

Originally Posted by rsl

Ampere hours (Ah)
Tested at 80 degrees Fahrenheit. It is the amount of current (in amps) a battery can deliver, multiplied by the amount of hours, without falling below 1.75 volts per cell (10.5 volts on a 12-volt). Most marine/RV-deep cycle batteries are rated on a 20-hour discharge rate. Example: a 100 Ah battery can deliver 5 amps for 20 hours (amps x hours = Ah).

So based on this, if I am understanding the math right I have a 58 Amp/Hour Battery?

Thanks RSL.......looks like I was reading the chart bass-ackwards.

58 hours makes sense.

[rsl]

OK so I have decided on going with 2 intersstate gc-2 batteries with 232 amp hours each. I have a contact who will give them to me at his dealer cost so they are going to run about $70 each. i figure 464 amps hours will last at least a couple of days rnning the heat, much more then my 58 amp hour capicity. Next problem what do I do about a big enough battery box?

[MtnGuy]

Originally Posted by rsl

OK so I have decided on going with 2 intersstate gc-2 batteries with 232 amp hours each. I have a contact who will give them to me at his dealer cost so they are going to run about $70 each. i figure 464 amps hours will last at least a couple of days rnning the heat, much more then my 58 amp hour capicity. Next problem what do I do about a big enough battery box?

Since the GC-2s are 6 volt batteries, you need to wire them in series, and I don't think the amp hours double in that case. Only when you have 2 12 volts wired in parrallel does the amp hours double. You still gotta a lot of power there.

[rsl]

ok yes you are right amp hours dont double, still need help on battery box(es)