Take extra batteries when boondocking?

[Dooger54]

We have had our RV for less than a year and just got back from 2 days in Organ Pipe National Monument dry camping. Very nice RV park but no hookups. We stayed two nights and ran on battery power. We will be doing more camping without hookups so I started thinking about ways to extend our battery power. We won't do enough to warrant a solar system and I prefer to not use a generator.

So I got to thinking that if I had another set of batteries (2 6 volt Trojan 105s) that was fully charged I could just unhook the depleted batteries and hook up the fresh ones. Obviously this would double the amount of time we could spend without electric hookup.

Anyone done this? Seems simple and relatively inexpensive.

[Hittntheroad]

Install a battery switch leave them wired up. Just flip the switch to change which 2 you need. We use them in boats all the time. I have one in my Thor.

[twinboat]

I'm assuming you don't want to install them with the others.
Bring the extra with you and hook them up as soon as you get there.

If you can run them down together it will be better for all of the batteries life and they will drain slower.

2, 6 volt batteries are about 225 AH at the 20 hour rate. That's about 12 amps for 20 hours.

With 4, 6 volt batteries, 12 amps is way under the 20 hour rate so the battery bank will drain slower and last more then twice as long.

This is from Trojan battery website.
5-Hr Rate =185 AH
10-Hr Rate =207 AH
20-Hr Rate =225 AH
100-Hr Rate =250 AH

You can see that the slower the battery drains the more energy it gives.

Another benefit to using them together is the less discharged they get, the more times they can be recharged.

If you run them down half dead, they can be recharged 1000 times.

If you run them down 3/4 dead, they can be recharged 500 times.

[Dooger54]

HMM... I nver thought about the batteries lasting longer if I hook them all together to begin with.

I have two reasons for not wanting them hooked up together permanently.

1) Adding two more batteries to my battery shelf in front of the RV would require me to modify the mounting system. It is not large enough to accommodate four batteries. I could modify it by welding on extra supports if I really wanted to. It would also add over 100 pounds to the front of the RV and I already am close to the limit I feel comfortable with.

2). My RV dealer installed two type 24 12v batteries when I purchased the unit. So that's what is on there now. If I buy two more batteries I would buy two 6v Trojans. I am not sure if I can hookup two 12v and 2 6v batteries together. Possible?

If I buy two extra batteries I will just transport them in my pickup bed.

[twinboat]

I thought you had a set of Trojan batteries. The batteries you have are small dual purpose types.

You could still connect them while discharging but probable should charge them seperate, only because Trojan batteries like higher charging voltages.

My recomendation is to take the 2, GP24s out, install 2, GC2 Trojan deep cycle batteries and give it a try.

The 2 Trojans, in series, will just about double the capacity of the 2 GP24s, in parallel.

If you feel you need more capacity, then add the 2 smaller batteries to the mix.

You can research the brand batteries you have and compare them to the Trojan specs.

Just remember that 2, 6 volt, in series only doubles the voltage, not the AH or Reserve Capacity.

[ajohansson]

What are you running electrically to wear down your batteries so quickly?

A must if your gonna boondock - LED bulbs or just swap out to LED 12 volt fixtures. I installed these in my last rig and loved them.

https://www.superbrightleds.com/more...tor/1382/3177/

I ran 2 - 6 volt Trojans in series and they were awesome. Charged off a 160 watt solar panel and all was good.

New trailer is gonna have 4 batteries but also now have a microwave I will run off an inverter. I did have an inverter before but mainly charged a lap top or ran a small fan when hot.

[Dooger54]

Originally Posted by ajohansson

What are you running electrically to wear down your batteries so quickly?.

Not really using much. RV is new and has all LED lighting. Water pump and furnace fan. No inverter at this point.

The Interstate batteries in now are Series 24 and two 12v. Total Amph for both is 150 combined. My plan is to buy two new T105 and replace with those. I will keep the Interstates fully charged in my pickup bed and swap them out when the Trojans get down to 50% capacity.

[Mzbrandi]

Originally Posted by Dooger54

HMM... I nver thought about the batteries lasting longer if I hook them all together to begin with.



I have two reasons for not wanting them hooked up together permanently.



1) Adding two more batteries to my battery shelf in front of the RV would require me to modify the mounting system. It is not large enough to accommodate four batteries. I could modify it by welding on extra supports if I really wanted to. It would also add over 100 pounds to the front of the RV and I already am close to the limit I feel comfortable with.



2). My RV dealer installed two type 24 12v batteries when I purchased the unit. So that's what is on there now. If I buy two more batteries I would buy two 6v Trojans. I am not sure if I can hookup two 12v and 2 6v batteries together. Possible?



If I buy two extra batteries I will just transport them in my pickup bed.

Sorry, but why don't you just put them on the ground (in battery box) and wire them to trailer batteries. I do this all the time.

Brandi

[nothermark]

FWIW I think you will find T105's are significantly larger and heavier than what you have now. Most people do not easily toss them around. IMHO you would be better off mounting them somewhere and running a long cord to add their output to your existing set. Better yet go solar or learn to love a generator. It does not take a large generator to charge your batteries but it does take time.

[Hit_the_Rhod]

Originally Posted by Dooger54

We have had our RV for less than a year and just got back from 2 days in Organ Pipe National Monument dry camping. Very nice RV park but no hookups. We stayed two nights and ran on battery power. We will be doing more camping without hookups so I started thinking about ways to extend our battery power. We won't do enough to warrant a solar system and I prefer to not use a generator.

So I got to thinking that if I had another set of batteries (2 6 volt Trojan 105s) that was fully charged I could just unhook the depleted batteries and hook up the fresh ones. Obviously this would double the amount of time we could spend without electric hookup.

Anyone done this? Seems simple and relatively inexpensive.

Not judging here, but I'm curious why you are against using a generator? A Honda EU2000 for instance has a built in battery charger, just sips gasoline, and is very quiet. You could run it for an hour in the morning and an hour in the evening when you electric usage will be the most. If you are minimizing your power draw, which it sounds like you are if you are getting by on batteries alone, it will charge your batteries up, and provide your other loads at the same time. Your batteries will last longer, and the cost of the generator will be offset by not having to purchase another set off batteries.

The Yamaha and Champion inverter generators show up well on reviews as well. And there's always the Predator 2000 sold at Harbor Freight. They are looking like they will give Honda a run for their money, half the price, 4 stoke, a little louder, but people I've spoken to say they're good. Just speaking out loud here, but it will allow you to extend your dry camping a LOT with just a two gallon gas can. The Honda will run for from 6 to 9 hours on 0.9 gallons depending on load.

Good luck in whatever you decide!

[Hittntheroad]

While dry camping at Martinsville I noticed a lot of the motorhomes had a Honda 2000 or 1000 to run during the day for charging batteries and watching tv. I bought one for mine.

[Off Road]

I think what is eating your batteries is the furnace fan. Even though the furnace is propane the blower fan just sucks the juice. I boondocked in cold weather for two weeks last fall in colder weather (20's and 30's at night) and used the furnace every night to keep the pipes from freezing. We ran our 2000 watt Yamaha generator every evening for 3-5 hours and burned a grand total of 10 gallons of gas. At $3 a gallon that's only $30. Those little inverter generators are quiet and cheap to run after the initial $1000 purchase. The batteries I have are two 6 volt and they would run the furnace all through the night but be weak by morning. A small inverter generator is the way to go in my opinion. I also have two 100 watt solar panels but generally use the generator when I run the furnace a lot.

[RubiconTrail]

You've gotten a ton of good advice here. Summary:

Your furnace is eating your battery power, no doubt, but it isn't dispensable. You need to use it to stay warm.

The group 24 batteries are not designed for deep discharge and for their size, don't have much capacity. Switch to the Trojans in place of the 24s and see how you do. Better yet, get discovers or even better, Lifelines. Each of these will improve your capacity and life marginally.

To support this kind of use with solar you will need in the neighborhood of 400 amp hours of panels in the winter, even in the southern desert. Research what will fit on your coach and see if this possible or feasible for the size and money.

Personally , I would go with a generator like a Honda or Yamaha in the 2000 range. It will fix this problem running just a couple hours a day, is quiet, efficient, and reliable. It also is value added for other uses around the house or wherever.

In addition I would add a high qualify multi level battery charger like a IOTA such as this one IOTA DLS-45-IQ4, 12V 475A Converter Charger w/ Internal IQ4.

Why? Because the charger that is built into the generators we are talking about are inefficient. They only charge at about 8 amp hours. You'll have to run it for hours to recharge your batteries. The charger I recommended will use the full capacity of the 2000 generator without overcharging, charge your batteries very rapidly, and is smart charger so would be appropriate to leave on the batteries when plugged in at storage. I would install it in place of whatever maintainer came with the RV.

[Dooger54]

A lot of great advice and I appreciate all the help. Here is my plan for now-

1). Buy two new Trojan T105 batteries and replace the Interstates that are there now. Even if I purchase a generator later I still want the better batteries. I will keep the Interstates as backups in my pickup bed, fully charged, so I can swap out the Trojans if they deplete while dry camping.
2). I have on order a Trimetric 2030-RV battery monitor that I will install. Part of my anxiety while dry camping came from the fact that I had little idea how fast or far my batteries were draining. The idiot lights in my RV panel are not much help. Now I will be able to know with certainty how my batteries are doing and how much power I am using.
3). Consider a generator for future use. I have researched the various units and would buy the Honda EU 2000. I'll just wait and see whether that will be worth it.
4) I will look at the Iota battery charger. One reason I have deferred buying a generator is because of the hours it takes for them to charge batteries. This might be a good option.


Thanks to you all-

Doug