[Chester Stone]

I am not satisfied with using 8D starting batteries for my house needs, and I am switching to twelve 6-volt deep cycle golf cart batteries. Attached is a photo showing how my six 8Ds are connected.

The batteries are numbered 1-6 with all grounded at the negative terminal of battery 3. As to positives, arrow A shows the positive cable from battery 3 goes to the cutoff switch and apparently supplies the house needs. However, arrow B shows that an additional positive cable connected to battery 6 which seems to be connected directly to the inverter.

From a previous posting I saved an article by Smart Gauge Electronics which shows different ways to connect multiple batteries, and the worst way is to have all of the batteries connected and the exit cables connected to one battery.

I would appreciate comments regarding the correctness of my existing setup. Would it be better if I had different grounds for the two bands and not all connected together? Should positive from one bank go to the cutoff and the other to the inverter, and should all positives be connected as they are now?
   

[Ozarkguy]

Chester. This may help
http://www.solarrvpanels.com/index.php/w...-properly/

[prairieschooner]

This is not the best way...supposedly the best way would be to have the (-) Cable at the 1st Battery and the (+) Cable at the last Battery. Or (-) at #1 and the (+) at #6. This way you would be making the Power run through all of the batteries rather than just using them in parallel if this makes better sense.
Another way to look at it is that the way you are connected primarily uses Battery #1 and the other 5 Batteries only provides power through the Battery Cables to THAT Battery.
Either way works just want you to see the most use of the power that you have.

[folivier]

Chester, let us know how the 6 volts compare to your 8D's. I'll replace my house batteries this winter and plan to use AGM's.
But I'm open to something better.

[encantotom]

forest, did you give up on the lithium battery approach?

tom

[rheavn]

Chester,
You indicated you are using 8D starting batteries for the house batteries. There are 8D deep cycle batteries available. Slightly more in cost($20-$30), but are the right battery for the job. Not trying to talk you out of changing, but maybe you just don't have the right batteries installed to do the job. I've been using 8D deep cycle batteries for 12 years and have no complaints.

[folivier]

I tried real hard to get the lithiums. Had a great price for the individual cells that would have been the same price as agms. But unfortunately the supplier quit returning my calls and emails. Guess they decided they didn't want the liability or to provide tech support. Lithionics who makes their cells here in the USA did give me a discount but the price for 2 450 amp hour batteries would be over $9500. Too much for me to spend right now. I would still love to go to lithiums but there is NO technical support just yet. Most of the suppliers, other than Lithionics, are designed for the electric vehicle drive systems which are high voltage systems. I learned a lot doing research and still believe lithiums would be an awesome house battery system. Just couldn't find anyone interested in selling to the RV market, other than Lithionics.
So yesterday Steve Magown helped me pull out 4 8Ds and get rid of them. My coach has 4 batteries in one compartment and 2 in a smaller compartment. I need to have the battery rack rebuilt since the acid has eaten up some of the metal rack. Then I'll clean and paint the compartment and rack. Thinking of using something like Zero Rust.

[whatsnewell]

Steve, what brand of 8D deep cycle are you using?

[Chester Stone]

Thanks everyone for your response. Jimmy, the fourth drawing in the article shows a very simple hookup arrangement for series and parallel connections. Steve, good idea to exit the ground and positive from different ends of the grouping. Forest, Costco sells International deep cycle golf cart batteries for only $90 with 232 amps. When you rebuild your rack, move the top tray up two inches to give a little more room in the bottom tray to hold the 11" batteries. I am replacing the caps on the new batteries with a low profile, gravity feed, automatic watering system. I am still curious about the dual positive cables, one out of the last (or first) battery in the line one one out of the middle battery in the line. Guess I will go with the way they are currently connected, except I will change the ground to the last battery and the positive to the first.

[rheavn]

Clarke,
I'm using ProGuide 8D deepcycles that I get from a local battery distributor here in Missouri. They indicate they are manufactured by Exide. Back in 2010 they cost me $160 a piece. I've used them for 12 years now.