:question: Need to replace house batteries which are two 6 volt in series. One has only 3.9 volts and other 5.9. Is it better to go with 3 twelve volt deep cycle in parallel? Have the room. What is the better system? Thanks for your input.
6V batteries tend to be 'better' (heavier duty) than 12v batteries (for deep cycle applications, anyway). That being said, go for the combination which gives you a higher 'AH' (amp-hour) rating for the amount of space you have. Let's say that 2 6V batteries will give you 180 AH, and 3 12V give you 75AH each. The latter system would give you 225AH, which is somewhat better. On the other hand, if the 6V batteries provided 220AH, I would go with them since the small increase in AH is not worth the flimsier construction of the 12V batteries.
Whatever you get, make sure all the batteries are the 'same' to avoid them 'fighting' each other.
Also, be aware that there are many 12v batteries out there which are sold for RV purposes which are not the best for those tasks. You want a TRUE deep cycle battery, which is one which has no Cranking rating at all, just an AH rating.
Thanks John for the info. It still is up in the air what to do as the cost will make the decision hard too. Where to find best deal and look for the nearest store? Costco, Camping World, others? Right now we are dead in the water but maybe I could substitute one 12 volt just to get by for the trip to the store. We are about 4 hours from our closest Camping World.
How much are you going to USE those new batteries? Are you going to do a lot of 'boondocking' where you don't have electricity and need to drain your batteries down to the bottom?
If the answer is no, then find your local seller of batteries and buy a pair of 12volt MARINE deep-cycle batteries. They are typically used for fishing boat trolling motors. They will work just fine for NORMAL battery needs.
A typical LOCAL seller of batteries could be WalMart, auto parts store, or sports equipment store (Academy, Bass Pro Shop, Cabela's).
Just measure for the physical size limitations of the hole you are putting the batteries in.
Wal-Mart sells 12 V marine/deep cycle batteries (Everstart) for about $60 for the biggest 1 (MAXX 29). I have used them for 10 years and have had good luck with them. Sam's Club also sells marine batteries ($65). I believe they are Interstate brand.
They may even sell 6 V golf cart batteries.
If you are near Tucson (or other big city), see if there is a battery manufacturer there. I've been getting mine from the manufacturer. Also check 'Batteries Plus' if there is one nearby (good selection, prices not the best).
I use Interstate 12v batts in my coach ,, but i don't do much boon docking ,, but i have had to use them a time or two when the campsight power went out and it was really late and i did not want to fire up the genset ,, so we switched everything over to batt. and watched the rest of our movie via 12 volts and inverter ,, but did kick the a/c fan on once in that time ,, but not the a/c part of it ,,, it was cool enough to be happy with just a fan
Thanks guys for the information. Purchased the two 225 AH 6 volt batteries after mulling over the input. Went to our next town to Walmart and Auto supply and the RV store and the RV store had the units for 140 each. Since this is our first motor home and first long trip we want to have the options for stopping most places. We don't know what type of travel stops we will do into this new area. Grand Canyon and AZ is our direction. Now I'm going out to even replace the connectors as they are too large and very dirty and corroded. Next is the hitch for the towed Ranger and a Brake Buddy.
If he still does it, the best way to see the (south rim of) the Grand Canyon is Marvelous Marv's Grand Canyon Tour. There is a RV park just of I40, about 30 miles west of Flagstaff (Canyon Gateway, perhaps). They belong to Passport America, so are cheap if you are a member. And they provide a discount for Marvelous Marv's tour if booked through them.
Marv will pick you up (at the park), take you to the Grand Canyon, show you all the best places, give you lots of neat information, answer questions, provide for shopping, and take you back. And the best part is, avoid all the crowds and hassles you often run into on your own.
I'll agree with hertig on the canyone tour! We stayed at Canyon Gateway about five years ago and had been going to ride the train up and the fellow at the park suggested we would get more for our money if we went with Marv. He was right. That fellow knows that canyon cold and truly loves it!