House battery recommendation

GaDawgFan · 09-29-2015, 04:59 PM

I currently have 4 six volt Trojans I need to replace. I am considering going back to 2 twelve volt's to save money. At the most I only spend 1 week per year camping where there is no shore power. Any recommendations for 12 volt deep cycles would be appreciated.

pasdad1 · 09-29-2015, 05:15 PM

Get 4 of these at Sam's Club.

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Mr_D · 09-29-2015, 05:27 PM

Quote:

Originally Posted by pasdad1

Get 4 of these at Sam's Club.

Attachment 108378

That's what I'm going to do next time. 4 8D AGMs at about $500+ each is too much for our needs. I don't mind putting mineral oil in GC2's and then checking the fluid level every couple months.

nothermark · 09-30-2015, 07:55 AM

If you do not want to run 4 because of the cost/capacity trade off run 2 6V and leave the other bank empty. If it turns out you want more populate the second bank.

AFChap · 09-30-2015, 08:06 AM

I use three Group 29 Marine deep cycle ...all I have room for. I normally get them at Walmart and run them 5-6 years before they start going South on me.

skigramp · 10-02-2015, 06:31 PM

I use three Group 29 Marine deep cycle ...all I have room for. I normally get them at Walmart and run them 5-6 years before they start going South on me.

Same for me ... Walmart no longer "warrantees" them ... I used to get reduction whenever they did not last for the warrantee period

Catcoach · 10-06-2015, 10:35 AM

I also use Wal-Mart and they do warranty their batteries. Bought three new ones last fall in Ithaca NY. Come this spring they were dead.. Took them to Wal-mart in Murphy NC, replaced all three no charge and I couldn't find my receipt. No problem. I'll stick with Wally World.

Journey39n · 10-07-2015, 12:01 AM

My oem 12v set of two batteries gave out after just over 1 year. First replaced with two 6v GolfCart batteries from Costco at $75 ea. A year later, added two more at $78 ea. That was three years ago. Still going strong. I think they go for $83 now?

GaDawgFan · 10-07-2015, 05:48 AM

Thanks for all of the responses. I decided to pull the 4 Six volts and replace with 2 Trojan T-105 six volts. I found them for $112 each. I will be dry camping next week and will see how they do. I can always add two more if needed.

HHIDan · 10-07-2015, 06:00 AM

If you do end up adding another bank a year later, I would say put one new battery in each bank. Don't put two new batteries in parallel with two old ones...

twinboat · 10-07-2015, 07:12 AM

I clipped the following from an article I googled.

My feeling is that a older battery is at a less capacity then a new one, just thru use.

Because of this, I disagree with splitting a pair of series batteries and using 1 new and 1 old.

ASK THE EXPERTS: Batteries in Series & Parallel

Connecting two battery banks of different amp-hour capacity together in series is a bad idea. The problem is that the battery charging controls will*operate based on the average battery voltage and the two batteries will have very different voltages because their capacities are different. The 100*AH battery will become fully charged long before the larger one. The combined voltage will rise, but by the time the controller turns off the charging*sources, the 100 AH battery will be overcharged. Meanwhile, the 200 AH battery will not get fully charged. When the bank is being discharged, the*100 AH battery will go flat and its voltage will fall well before the 200 AH battery. The inverter will eventually cut out but not before the 100 AH*battery is excessively drained.

Connecting two banks with different capacities in parallel is technically fine since the batteries will be operating at the same voltage. Charge and*discharge current will be shared, based on capacity. It is best if the batteries are of the same type and age. For example, avoid combining a sealed*(gel or absorbed glass mat) battery with a flooded (conventional) battery because they have different charging setpoints. Broadly speaking, you can*parallel batteries without problems, and the charge controller will look after them. Just make sure you give them plenty of charge. If the system*tends to operate at less than a full state of charge, adding new batteries to old will probably just result in the old ones pulling the new ones down*and everything getting even.

HHIDan · 10-07-2015, 08:59 AM

I agree that all new (or same age) is better.

I also agree that under charge both banks regardless of how they are connected get the same voltage and the two banks charge at different rates but both banks will end up at their respective peak amp-hours which will be slightly different based on their different ages.

When you disconnect the converter/charger and even if there is no load the two new batteries will loose amp/hours trying to bring the old ones to the same volts until they reach a balanced state.

Lots of articles, it's debatable...

If it were my coach I would find another use for the old ones and get all new.
Otherwise I still am under the opinion that all banks should be as similar to each other as possible...

nothermark · 10-08-2015, 05:16 AM

If he will be dry camping a week after replacing the 4 with two he will know in a day or two if he needs another pair. That renders the rest moot. If I was really nit picky I would reserve 4 and use two then I could get the other two out of the same lot. ;-)

bobmac · 10-08-2015, 05:08 PM

I have 4 of the Sam's Club Group 31 AGMS by Duracell. Have had them for 2+ years with no issues. Great batteries at the price point. I would highly recommend them.