I need some help planning my camper electrical...

[VicR]

We have a few trips planned this spring and fall, so I better get to work on improving my camper electrical. I have a 2000 Sunlite Eagle SB pop-up slide in camper. My goal is to have a system that will support us dry camping for about 5 nights. We do a lot of trips in May, September, and October, so having that furnace at night sure is nice. The coach battery went dead on our last trip to Yellowstone, and I caught heck because the furnace wouldn't work.



The only electrical draws are:



Suburban 20000 btu furnace, the water pump, and the reading lights. I am figuring the furnace is the biggie in this plan.



Most of our trips involve only short times running the truck mid-trip. Also I don't want to use anything but the trailer plug for tieing into the trucks electrical because the camper will go on at least 2 trucks. And the hot wire from the camper is pretty light, so I am assuming that there won't be much mid-trip charging from the truck.



So... based on this info: I can't find the data on my furnace, but the furnace thats one step bigger (24,000) is rated for 3. 5 amps. Using that, and knowing that I want to run it for 40 hours on a trip, I need 140 amp-hours. Add the pump and lights and I figure I need 160 amp-hours.



Am I anywhere close on this reasoning? I have room for multiple batteries in my battery locker, but like any slide in, space and weight (and $$$!) are factors.



Anyone have any thoughts on this issue?

 

[msimmons]

Vic:



For your intended use, I would recommend getting two 6V golf car batteries and wire them in series for 12V. I don't know the ampacity of the GC batteries, but I think you will be close to your needs. You may want to consider several solar panels for the rooftop to help replenish the batteries during daylight hours. They are no subsitiute for the truck alternator or battery charger, but for your use every amp counts!



For certain, I would make sure that your vehicles starting batteries are isolated from the coach so that your truck will start when needed.



Hope this info helps!



Mike

 

[hmickelson]

Vic, Mike is correct if your camper can handle 2 Tall batteries. My rigs will not accomodate the height. Your surburban fan pulls about 8 1/2 amps per hour x 40 hours, your dead in the water. All else fails get a Olympian Wave Catalytic safety heater. the smaller one should work in your camper, it works in my old Alpenlite 25 .complus 2. try< http://www.uscatalytic.com >



Or U S Catalytic corp

871 Latour Court

Napa, CA94558-6258 707 255 4181



If the have a dealer in Reno they will tell you if not you may order on the phone



My older camper ,a Dynacruiser, has a fan that I can turn off and the pilot light seemsto be enough heat for 8 1/2 footer.

you had better compute you daily amp usage before you do anything.



lots of luck



Hugh

 

[TowPro]

I also 2nd the notion on using the golf cart batteries, 2 will be going in my PU camper, and 2 in my Dads motorhome this spring.



In your type use where you are running them pretty far down, then rechaging them is why you need deep cycle. 2 golf cart batteries will last more then 2 X as many cycles as a 12V deep cycle. There was a great review on batteries about 2 years ago in Trailer Life, I was amazed at how 2 Golf Cart lead acid batteries run in 12V would outlast a 12V deep cycle battery in both life, and time between recharges.



Plus as the other person said, Solor is a choice, But its expensive. Very little power for the space (and money) it takes IMHO.



Something else to check into is a real small (quite) Generator that has a 12V output. I feel in most cases, it's better to use a generator's 12V source to charge a battery as most RV's only have a 5 amp charge circuit built into there AC converter.



the little Honda EU1000iA2 puts out 8. 3 amps at 12V, runs something like 9 hours on a 1/2 gallon fuel, weighs 29 lbs and is real quit.



There are several small ones, Honda, Yahaha, mitsubshi. Another option is to go ahead and wire a better circuit from your truck to charge it, but that might be louder then a 1000w generator.

 

[klenger]

You may find some usefull information on my website at http://www.klenger.net/arctic-fox/solar/index.html

 

[RCook]

Vic, if I understand your needs correctly, you need to pull 160AH from your battery bank before recharging much. If that's correct, you need a deep cycle bank at least twice that big, or 320AH.



Batteries frequently drawn down below 50% of capacity have greatly reduced life.



A pair of Trojan T105's (a quality golf cart battery) has 225AH capacity. If your batteries will usually be drawn down only 110 or 120AH, the pair would be sufficient. Golf cart batteries are 6V, so must be installed in pairs.



Another alternative, if you're willing to pay considerably more for a more trouble-free setup (greater tolerance of deep discharges, less degradation when sitting unused, no checking fluid levels, no maintenance, no spills, no venting) is a pair of group-31 sized AGM batteries.



AGM's made by East Penn Mfg. provide 105AH each, or 210 for a pair. You could also put in three of those, for 315AH total.

 

[MDW]

Trojan batteries

I switched to Trojans myself



You could carry some extra batteries in the back of the truck and switch them out when they go dead. Can you say insurance

 

[B.G. Smith]

And

If you have incandescent lights you can save some energy by switching to fluorescent lights. I think the standard incandescent bulb pulls 1 1/2 amps. bg

 

[TowPro]

Re: And

this reminded me that I went into the lights over the beds in my PU camper, and replaced the bulb with a small side marker type. It gives enough light to read, and saves power.



My 5th wheel has 2 bulbs per light over the beds, I replaced the first bulb that comes on with a side marker bulb, and left the other bulb alone. Slide the switch one positon, its the dimmer bulb, slide it to the 2nd position and you have the bright and dim bulb on.

 

[VicR]

Answers and more questions

Ok, I have been digesting all of this, but I have a few basic questions:



1. West Marine (which has some really good tips for novice electrical people like me) has a 6v deep cycle battery with 215 ah for only $99. 99. So if I got two of those in series, would I have 215 ah still?



2. If hmickelson's numbers are right and my furnace draws 8. 5 ah instead of 3. 5 (I got my info from the camping world catalog - it was the only source handy I could find), this discussion is probalby not solvable and I'll have to go with a non-battery option.



3. If I had 2 6v's in series, how would that impact charging? I suspect it would get a small charge whenver I had the camper plugged in to run the running lights, etc. Would that be a bad thing?



4. Also, my camper has a 20 amp converter for charging built in. What does that mean and is it good or bad?



5. The more I read about 6v's, the more I like them. Those West Marine 6v's are good for 700 complete discharge/ charge cycles.



6. Last question: Why would I need a bank thats double my intended usage? Is that for battery longetivity? Would that be solved with a battery that was not sensitive to deep discharges?



Thanks for the advice!



-Vic

 

[dalton4]

Vic, check Sam's or Costco. You can buy two of their golf cart batteries for the same price range you stated for the one deep cycle marine battery. Golf cart batteries have the best construction for deep charging and discharging.

 

[JWhitcomb]

Keep your battery if it is in good shape, get a 1000 watt Honda gen set and a 20 am battery charger. The gen is very quiet, sips gas, and light to carry. I would also get a cat heater just to be in hog heaven.

 

[RCook]

Vic,



1. When you wire two 6V batteries in series to get 12V from them, you don't double the 6V-rated AH. You get the same AH capacity, but at 12V rather than 6V.



Two batteries wired in parallel, on the other hand, provide the same voltage, but twice the AH.



3. I don't know what the charging rate is when your camper is plugged into the truck when on the road, but it surely helps. I don't use the heater in my trailer much, and I run my fridge on propane, but I most often camp in places w/o plugin's, and have yet to run the batteries dead.



4. A 20A converter should be able to recharge your battery bank when plugged into 110V pretty well, but converters are usually not the most intelligent chargers, so you may not want to leave it plugged in for days at a time if there is little or no use of the batteries - they can get over-charged and thus damaged.



5. 6V's are particularly good not only for their capacity for low cost, but for their ability to handle a large number of discharge cycles. Very good total cost of ownership. If you are going to use them for days at a time w/o recharging, be sure to check fluid levels fairly frequently and top up with distilled water if they get low.



6. Any flooded (standard lead-acid) battery that is repeatedly discharged much below 50% of its AH capacity will die an early death. That's just the way they are. (AGM's are much less sensitive to this. )



Cruising boaters who anchor out figure they should have a battery bank that holds at least 3X (or 4X) their AH usage between charges. The number of cycles you can get from a battery before its death is greatly affected by how low you discharge it.



The best way to run a flooded deep cycle battery bank is to discharge no lower than 50%, and expect that charging will often bring the batteries up to only 85% or so. That last 15% at the top is very time-consuming to achieve. So in effect you get to use only 35% of the capacity - if you want longevity.



BTW, since you're looking at the West Marine catalog, the group 31 AGM's I mentioned earlier are there - those are the good ones made by East Penn. I paid $150 each for mine, from another supplier. Pretty expensive, but many advantages for a cruising boater.

 

[hmickelson]

Vic, Before you decide what you need you should survey your electrical needs by making an appliance consumption worksheet.

Basically, each appliance or light has a plate that indicates the hourly amperage consumption. with that info you determine your usage needs hours and go from there.



suggest you be methodical and thorough about your need assessment. When you determine your amperage needs then figure out what is out there to meet you needs, rather solar , generator or addition batteries or a little of each.



A very knowledgeable is Noel Kirby at RV Solar Electric try RVSolarElectric.com. He has a catalog and design planner which should fit your bill. Study the situation completely and your knowledge will succeed.



Best of Luck



hmickelson

 

[Casey Balvert]

All the advice above is great. Just to add to it. If you don't have a decent charger, you will pay for one in batteries. Cheap chargers will cause the battery to fail prematurely. Buy good batteries such as the Trojan mentioned above. If you buy from Walmart, they will work but be prepared to replace them more often. With a good charger and reasonable energy management you should be able to get five years minimum. Also, figure on derating most flooded cell batteries by 20%. With the exception of good sealed gelled electrolyte batteries, the manufacturers tend to be very optimistic. FWIW



Casey

 

[hmickelson]

Don't know what kind of converter you have in your camper but: Recently changed out old converter that weighed a ton and 1/2 for an Intel Power 9100. this puppy controls the charge rate based on what the battery needs. I have had it for about 5 months keep it on full time here in storage. Check batteries regularly and no low water as yet and they are fully charged.

I have Trojan batteries(not golf cart they will not fit, too high). It's by Progressive Dynamics Inc In Marshall Mi phone 616 781 4241



for what it's worth



hmickelson

 

[Philsram]

Camper electrical

Hey Vic,

I own a 1997 Lance cabover camper and have had similar problems with losing the battery running the heater. The fans just draw way too much out of the battery if it is cold outside and is running all night and day. I just went hunting in the fall and it was 18 degrees outside at night. Needless to say my heater ran all night. Right about dinner time I would turn on my 1000 watt Honda genterator and let it run for an hour or twoto charge up my battery. I never had a problem with it since. The golf cart idea sounds good also. PW