Trailer Batteries

[83Excella]

I am going to replace my battery and thought about adding a second battery as the other space is there for it, is anyone using 2 batteries? what are the advantages of using 2 over 1? the only thing I can think of is my 12v power can last longer on 2 than 1. Other than that whats the difference?

John

[FrankR]

http://www.windsun.com/Batteries/Battery_FAQ.htm
http://www.trojanbattery.com/welcome.html
http://bart.ccis.com/home/mnemeth/12volt/12volt.htm
http://boards.eesite.com/board.cgi?boardset=rvforum


Lots of great info on the net..Frank

[83Excella]

Thanks for the info Frank those are some good links, I'd still like to hear what the 2x battery users think.

John

[thenewkid64]

John,

We had a second battery installed in our 77 Sovereign prior to full timing in 1996. We also added 4 solar panels and a 1500-watt inverter. The 2 batteries made an immediate difference in our ability to boondock even before the solar. The biggest I experienced was not being so worried about running out of battery power. We were living in Wisconsin and started using out trailer early in the year and even took it out in winter. Frank's post on the vehicle charging 2 batteries was my experience, but if I towed for a long distance 200-300 miles the tow vehicle would put some charge in the batteries.

So my recommendation is add the second battery. In this case more is better!

[davidz71]

83Excella,
When I bought my '77 Excella 500 from a fellow in AZ., it had one old 12 volt Delco Voyager and a new Duralast battery. The 105 amp hr Voyager fit one compatment fine but the Duralast (also a grp. 27 battery) was too long for the battery box. I sold both batteries and bought 2 new Voyager 105 amp hr batteries. I then added a 5 watt Solargizer Solar Charger/maintainer unit that I place on top of the unit next to the forward vent. I use the trailer on weekends during the hunting season and have not run out of battery power even using the furnace for 3 nights at a time. While I start out with 210 amp hr with the 12 volts together, if you went with two 6 volt 220 amp hr. golf cart batteries together, you would end up with 440 amp hrs. to work with. Boondockers are recommending from 2 to 4 of the 6 volt batteries for plenty of power. I'm happy with the choice I made but if I had one large battery compartment, I would definately go with 2 of the 6 volt golf cart battery to start out. I have access to water but no electricity where I camp. If I had a microwave and an inverter, I would go with the recommended four 6 volt batteries along with a 120 watt solar panel. See www.rvsolarelectric.com as one source of recommendation.

[83Excella]

davidz71,
Your setup is what I'm aiming for 2 batteries and a solar charger/maintainer. 3 days using the furnace with just a 5w solar panel is pretty good, the furnace does eat power, is your solar panel permanently mounted? I would think one would need more than 5w to keep 2 batteries up to speed. Ive read about the golf batteries but I'm just going to work with what I have space for and adding a solar panel would be the perfect topoff, thanks for the info.

John

[davidz71]

John,
You have to realize that it is just me and occasionally a friend staying in the trailer over a 2 to 3 day period. Lights are only used for an hr. in the a.m. before daylight and for 2 to 3 hrs. during the evening. While out hunting in the a.m. until noon, the furnace or catalytic heater are not running. After lunch, I rest for 2 to 2.5 hrs. then i'm out hunting again. During warm weather, I will run an old fan, sometimes 2, pushing air over me to keep cool. I'm not using the water pump since water is available. Even with heavy use over a 3 day period, it seems that the batteries are fully charged when i'm back Fri. afternoon after leaving the previous Sun. evening. I credit part of this to the Solargizer Solar Charger and Maintainer unit which shakes the plates of sulphur according to their literature. This has suprised me also. I've thought about getting another 5 watt unit to add to the other battery for a total of 10 watts but I may just go with a 120 watt panel from rvsolarelectric.com. When the trailer is at the house, I have a Battery Minder unit hooked up in addition to the Solargizer and I highly recommend that type of charging unit. It is small, starts with a full charge then tapers off when you get close to 90 % charged. It also desulphates the batteries while bringing it up to full charge then maintains the batteries. This takes care of frozen batteries, partially discharged batteries, etc.
I have yet to have the battery gauge on my command unit show the batteries into the fair area. I really will get a chance to test it this Thurs., Fri., Sat., Sun. and Mon. since I will be in the during this time. I'll let you know what happens.

[davidz71]

John,
I forgot to mention that the glass panel was mounted on a aluminum plate with had 3 two inch wide by 10 inch peel and stick strips. I haven't peeled the strips off so that I can position the panel on top one side or the other or lay it on my awning to gather the most sun. I just put it on top and angle it slightly to the side where the sun is most likely to be shining. It seems to work. Solargizer also makes a 10 watt unit and I bet it's a dandy.

[Silver Hawk]

"if you went with two 6 volt 220 amp hr. golf cart batteries together, you would end up with 440 amp hrs."
Only if you wired them in parallel - but you would only get 6 volts to your system.
In series you would get 12 volts - but still only 220 amp.hrs.
Still, better than two 12 volt batteries.