Adding Better Batteries / Possibly Solar

[rpotter]

We recently purchased a new 2015 3570RS 5th wheel and were having issues with the batteries not holding a charge. We have the residential fridge but we did not use the inverter and so that is not adding to the issue. Basically after 2 days on shore power and the RV battery indicator showing full charge we took our trailer to storage, turned both disconnects to the disconnected position and within a week found the batteries now showing 1 light above discharged again. The batteries are charging but seem to drain very quickly with no draw. We tried dry camping one night with just the furnace on and found after as little as two hours the batteries were so low they wouldn't even power a single led light. In the morning we ran the truck for about 20 minutes and then were able to get all three slides retracted while the truck was running.

We are looking at buying much better batteries and would like opinions on using 6 volt deep cycle batteries or 12 volt type 31 deep cycle batteries and how many. We do dry camp on long hauls but for only for a day at a time (usually at a rest area or RV/Truck Centre). We basically drive about 8-10 hours in a day or more and then pull in for a nights sleep and then on the road again. We need enough capacity to run our Residential fridge for the night and the furnace when traveling during colder temperatures and of course enough capacity left over to bring in the slides in the morning. We have a brand new F350 diesel with the optional higher capacity alternator. I am not sure if any discharge during the night would be fully recovered during the next 8-10 hour drive. So what would you recommend. Two 6 volts, four 6 volts, two or more 12 volt type 31, etc. We thought of adding solar but since we usually stop during the night and are on the road in the morning i am not sure that would add any benefit. Unless of course we would need something like that to get the batteries fully charged before the next stop. The dealer felt that any discharge during the night would be recovered within the 8-10 hour drive. Your thoughts.. Thanks..

 

[danemayer]

Hi rpotter,

Before getting new batteries, you ought to look for something that might be draining them. Even with the cutoff switches OFF, the battery is still connected to the emergency breakaway switch in the pinbox. You also may have a direct connection from the battery to the generator start, if you have a generator.

One experiment you could run would be to charge the batteries, then disconnect the positive cable to see if they hold a charge.

You should also check the fluid level in the battery cells.

 

[rpotter]

Hi rpotter,

Before getting new batteries, you ought to look for something that might be draining them. Even with the cutoff switches OFF, the battery is still connected to the emergency breakaway switch in the pinbox. You also may have a direct connection from the battery to the generator start, if you have a generator.

One experiment you could run would be to charge the batteries, then disconnect the positive cable to see if they hold a charge.

You should also check the fluid level in the battery cells.

I will definitely give that a look. We have the gen prep package but don't actually have a generator. I will be getting the trailer out of storage in a couple of weeks and plan on having a proper battery test done at a local auto shop. Anything i have just shows the voltage in the batteries.. i don't have the ability to test for an actually amp draw test which the shop will be able to perform.

 

[caissiel]

Even with larger charge wire from truck to trailer it was not possible to keep my 2 batteries charged while on the road for 10 hrs each day. Now we have a propane fridge.
Adding a 200 watt solar system keeps the batteries at 100% on the road and the batteries for the first time lasted past 2 years.
The line from the truck batteries are so small that it barely charges the trailer batteries. The trailer converter charges the batteries to 65% according to my solar monitor. So leaving with low batteries and barely charging on the road leaves normal batteries dead in no time. Solar is the only solution for me.

 

[avvidclif]

If you look around you will find the CO detector and smoke detector are never disconnected in my experience. Add in a 12v radio and the batteries are dead in abt a week or less.

 

[fredwrichardson]

We recently purchased a new 2015 3570RS 5th wheel and were having issues with the batteries not holding a charge. We have the residential fridge but we did not use the inverter and so that is not adding to the issue. Basically after 2 days on shore power and the RV battery indicator showing full charge we took our trailer to storage, turned both disconnects to the disconnected position and within a week found the batteries now showing 1 light above discharged again. The batteries are charging but seem to drain very quickly with no draw. We tried dry camping one night with just the furnace on and found after as little as two hours the batteries were so low they wouldn't even power a single led light. In the morning we ran the truck for about 20 minutes and then were able to get all three slides retracted while the truck was running.

We are looking at buying much better batteries and would like opinions on using 6 volt deep cycle batteries or 12 volt type 31 deep cycle batteries and how many. We do dry camp on long hauls but for only for a day at a time (usually at a rest area or RV/Truck Centre). We basically drive about 8-10 hours in a day or more and then pull in for a nights sleep and then on the road again. We need enough capacity to run our Residential fridge for the night and the furnace when traveling during colder temperatures and of course enough capacity left over to bring in the slides in the morning. We have a brand new F350 diesel with the optional higher capacity alternator. I am not sure if any discharge during the night would be fully recovered during the next 8-10 hour drive. So what would you recommend. Two 6 volts, four 6 volts, two or more 12 volt type 31, etc. We thought of adding solar but since we usually stop during the night and are on the road in the morning i am not sure that would add any benefit. Unless of course we would need something like that to get the batteries fully charged before the next stop. The dealer felt that any discharge during the night would be recovered within the 8-10 hour drive. Your thoughts.. Thanks..

Not sure what size batteries you have but something is not right. Either your batteries are bad or you have a large current drain somewhere in the RV. First I would have the batteries tested. If that is good then I would see what type of current you are drawing from the batteries. If it is high then you need to start disconnecting things till you find the current hog. As far as batteries I would go with the 6 volt (golf cart) batteries in serial (makes 12 volts) and if you have room for 4 then you would have 225 Amp Hours times 4 or 900 Amp Hours of energy at 6 volts or 450 Amp Hours at 12 volts. The average residential refrigerator is 615 watts or 615/ 12 volts = 51.25 amps per hour but that would be if the compressor was on all the time. If we factor 33% duty cycle (on 1/3 of the time) then it would be approx. 17 amps per hour or you could run the refrigerator 26 hours. Need to factor in inverter efficiency at 90% then you could run the refrigerator 23 hours without recharging. If you just had two 6 volt batteries then you could go 11.5 hours. So you know the furnace actually draws quite a bit of power at somewhere between 8 to 11 amps per hour when on and at 50% duty cycle would be 4 to 5.5 amps per hour. So to run the refrigerator and the furnace through the night would be 17 + 5 or 22 amps per hour. That would be 9 hours with two 6 volts or 18 hours with four 6 volt batteries. I am pretty sure the factory batteries are no where near the amp hours to get you through the night with both furnace and refrigerator on.

 

[rpotter]

Wow thanks Fredwrichardson, that's a fantastic detailed response. I will look into getting 4 golf cart batteries and possibly augmenting with solar charging. I wonder how many amps are being delivered via my F350 to the trailer. I believe my alternator is rated for 225 amps but not sure how much of that gets to the trailer. I am not sure if the truck would keep up with the fridge inverter draw while driving or it would be a losing battle.


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[LIREALRE060210]

We have 2 Trojan T105 6V batteries

We boondock one night between rv parks when we are traveling long distances, we have done 2 nights but batteries get low with furnace running a lot and Res. Fridge

 

[donr827]

I had a similar problem. A few days after returning from a trip I checked the batteries and noticed that the voltage on the batteries had dropped a little. Went back to the storage lot the following week and noticed that the voltage dropped even more. Took both batteries home and charged them. One battery held the voltage while the other battery slowly drained down. The cause was a bad cell. Since the batteries were fairly new I replaced the one under warranty and no more problems.
Don

 

[fredwrichardson]

Wow thanks Fredwrichardson, that's a fantastic detailed response. I will look into getting 4 golf cart batteries and possibly augmenting with solar charging. I wonder how many amps are being delivered via my F350 to the trailer. I believe my alternator is rated for 225 amps but not sure how much of that gets to the trailer. I am not sure if the truck would keep up with the fridge inverter draw while driving or it would be a losing battle.


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Because of the gauge and length of wire that runs from your truck to the unit and with the larger batteries it should keep everything going but it is not going to add much charge to the batteries.

 

[rpotter]

We have 2 Trojan T105 6V batteries

We boondock one night between rv parks when we are traveling long distances, we have done 2 nights but batteries get low with furnace running a lot and Res. Fridge

When you say you have gone two nights.. is that two nights at one stop or one night then drove a number of hours then stopped for a second night?

 

[fredwrichardson]

We have 2 Trojan T105 6V batteries

We boondock one night between rv parks when we are traveling long distances, we have done 2 nights but batteries get low with furnace running a lot and Res. Fridge

The Trojan T105 6V are great batteries. Being wet batteries you just have to make sure you check them but with the correct maintenance they will last you 10 years.

 

[LIREALRE060210]

When you say you have gone two nights.. is that two nights at one stop or one night then drove a number of hours then stopped for a second night?

2 nights at one location

 

[EPaulikonis]

First observation...don't trust the battery meter lights on the coach. They're nowhere near accurate when it comes to true battery health. Go out and get yourself a basic Ohms meter to check voltage. If you have a generator, like a Honda 3000is, that has a 12v DC capability, use it to charge the batteries directly as it provides more amps and will bring the battery to a full charge.

State of Charge on 12V/6V: 100% 12.7V/6.3V, 75% 12.4V/6.2V, 50% 12.2V/6.1V, 25% 12.0V/6.0V, Discharged 11.9V/6.0V according to Battery Stuff.

If you're considering switching to 6v batteries or adding solar, do some homework before you make the jump. I've been considering the options because I also have a Landmark with a residential refrigerator and would like to have the flexibility to boondock on occasion. The best resource I've found so far is from a company in Oregon, AM Solar. The educational links break down all the different parts and will lead you to a system sized for your power consumption habits. Topics also highlight the trade space between some of the battery types (cranking, deep cycle, deep cycle marine).

One drawback to 6v is they have to be paired, so if you replace one, you should replace the one in parallel with it; otherwise, they spend more time trickle charging each other and don't provide output power. Understanding how to manage solar so you don't destroy batteries is also important. Most solar owners will tell you to avoid spending crazy money on batteries until you get a handle on managing your solar power system.

The first step I'm taking is to purchase a battery monitor to understand my power habits. Once I have that piece squared away, I'll start sizing the solar system to handle my tendencies. Best of luck working through the power learning curve.

 

[scottyb]

First observation...don't trust the battery meter lights on the coach. They're nowhere near accurate when it comes to true battery health. Go out and get yourself a basic Ohms meter to check voltage. If you have a generator, like a Honda 3000is, that has a 12v DC capability, use it to charge the batteries directly as it provides more amps and will bring the battery to a full charge.

State of Charge on 12V/6V: 100% 12.7V/6.3V, 75% 12.4V/6.2V, 50% 12.2V/6.1V, 25% 12.0V/6.0V, Discharged 11.9V/6.0V according to Battery Stuff.

If you're considering switching to 6v batteries or adding solar, do some homework before you make the jump. I've been considering the options because I also have a Landmark with a residential refrigerator and would like to have the flexibility to boondock on occasion. The best resource I've found so far is from a company in Arizona, AM Solar. The educational links break down all the different parts and will lead you to a system sized for your power consumption habits. Topics also highlight the trade space between some of the battery types (cranking, deep cycle, deep cycle marine).

One drawback to 6v is they have to be paired, so if you replace one, you should replace the one in parallel with it; otherwise, they spend more time trickle charging each other and don't provide output power. Understanding how to manage solar so you don't destroy batteries is also important. Most solar owners will tell you to avoid spending crazy money on batteries until you get a handle on managing your solar power system.

The first step I'm taking is to purchase a battery monitor to understand my power habits. Once I have that piece squared away, I'll start sizing the solar system to handle my tendencies. Best of luck working through the power learning curve.

Good post. The 1st thing you need to do is get some real deep cycle batteries and get away from the hybrid marine batteries. 6V batteries are cheaper per Ah than 12V, and have a slight weight ratio advantage over comparable 12V deep cycle. If you go the cheap route like the Energizer GC-2's vs marine batteries, they are hands down a better option. You can purchase GC-2's at Sam's or Costco for around $80. $320 will get you 450 Ah @ 12V. They will probably not last as long as Trojan T-105's but they don't have to. When I add solar and replace my batteries (6), I will go with Lifeline GPL-6CT. It will give me 900 AH @ 12V and in the same footprint as the GC-2's.

 

[Bohemian]

2-6v batteries with the same total capacity as 1-12V battery from the same series (e.g. Trojan golf cart deep cycle, or other series) have the same efficiency because the 2V cells inside are the same cells. The 2-6V batteries will weight less each but more in total. They will take up more volume because of the additional casing. They will require more connecting cable.

 

[scottyb]

2-6v batteries with the same total capacity as 1-12V battery from the same series (e.g. Trojan golf cart deep cycle, or other series) have the same efficiency because the 2V cells inside are the same cells. The 2-6V batteries will weight less each but more in total. They will take up more volume because of the additional casing. They will require more connecting cable.

They also have a slight advantage of weight / AH @ 12V over comparable 12V batteries, such as Trajans.

 

[bsuds]

We had a similar problem with ours when we first bought our Big Country. The tech found a loose connection on the terminal block on the ground connections I think so the batteries were not getting a proper charge. Either way it has been fine since but we don't boon dock so I cannot say how long they would last doing that.
Have added a disconnect switch on the positive side so my batteries are definitely disconnected when that is off.

 

[Bohemian]

They also have a slight advantage of weight / AH @ 12V over comparable 12V batteries, such as Trajans.

1-12V battery with the same capacity as 2-6V batteries from the same series will weigh less and have less volume and require less cabling. The weight and volume reduction for the 12V comes from the simple fact there is less casing and fewer posts.

 

[caissiel]

But if I am right the 6 volts seam to have heavier plates and more room for acid.
I do prefer 12 volts and all my battery worries are taken care with my 200 watts solar system.
Pay back completely on battery life.