School me on Batteries

Got the RV my daughter bought to the house.
Got it hooked up and while I have not checked the gas side; the fridge and water heater are working on 110. A/C blows cold and inside looks in good shape.
It will need a new rubber roof soon but I do not see any leaks yet and we can use a carport to protect it till then.
For $900 I think she did OK.

So now I try to fix the 12 volt system. It has one of those make believe deep cycle 12 volt batteries in it. A marine cranking battery with a deep cycle sticker on it. They said it was bad but I put a charger on it and it charged up. So I suspected the onboard charger was bad and sure enough it is.

SO...........
1) While I can use this marine 12v battery for a while they really are not made to last with constant charge and discharge; and a new set of Trojan 6v batteries get pricy.
Any one have experience with other 6v batteries like Sam's or Costco sell.
What true deep cycle 6v flooded cell battery do you recommend.

2) The converter/charger is dead and will need to be replaced. I found some paper work in the trailer on it and do not like what I see on this old charger so do not really want to replace with same. It only charges at one constant low setting.
Got to looking around on the net for a multi stage charger that could deal with Lead Sulfate problems better than a constant low charge from a single stage charger.
Found the Progressive Dynamics PD9245C, 45 amp power converter with a built-in Charge Wizard.
Any comments you can make on this item??

Thanks
Any and all comments welcome
Progressive Dynamics PD9245C

My Brother in law pipelined for 40 years and he lived out of a travel trailer probably 300 days a year the whole time. He always traveled with a golf cart for errands and he ran Trojan 6 volts in the golf cart and the RV, they must of done the job because he didn"t like to work on anything and he would spend the money to make sure he was set and ready no matter what it was.

I installed a progressive dynamics innverter/charger in my rv. I got good service out of it.

Looks ok. Some of my co-workers use a system that charges the 12V system when when plugged into AC. When the AC is unplugged. The charger/converter become an inverter turning the 12VDC into 120VAC.
Computer UPS units can sometimes provide similar performance.
JdMaris posted a link here a while back on very resonae priced charger/inverters.

If I had a 12 volt system with multiple batteries. I would use 12 volt batteries hooked in parallel not 6 volt batteries hooked in series. I've worked as a mechanic for over 30 years and all the 12 volt systems I've ever seen that used 6 volt batteries hooked in series to make 12 volts never performed properly. When batteries are hooked in series all it takes is one bad connection and you're down. You can have 10 batteries hooked in series and one bad connection makes an open circuit in the entire system. Now if the 10 batteries were hooked in parallel one bad connection would eliminate the one battery that had the bad connection but yet all the other batteries that had good connections would still work.

But do they make a true deep cycle 12 volt battery that can be picked up by hand??

6 volt batteries may be a pain because of connections but the plates are heavier making the battery last longer.

I am not really worried about amp hours because it will be plugged in all the time.

By definition - a deep cycle battery is one that is built to withstand many 50% discharges. Walmart hybrid marine deep cycle type 24s, 27s or 29s are fine for RV use. They are made by Johnson controls and tested to X amount of 50% dicharges.

The Walmart deep cycles are fine. So are Trojans or the GC2 equivalents from Deka -but they cost more and last longer. Trojans are junk if you want to compare them to Rolls-Surette (made in Canada). The Trojans cost more then the Walmart types, and the Rolls-Surette cost more then the Trojan. A classic case of getting what you pay for.

I've got four RVs and have used the Walmart batteries in all but one that has a pair of Trojan T105s. I'd never buy Trojan again. They've gotten way too pricey and being 6 volts - not very useful in anything else.

Note that the BCI type 29 from Walmart in my Toyota motorhome cost $89 four years ago and has worked great as an RV "house" battery. If it dies tomorrow - it owes me nothing.

The Progessive Dynamics are very good combo chargers and converters if that's what you want.

I use a marine "Guest" dual batter charger in all my RVs. Three stage charge that charges/maintains the cranking battery as well as the "house" battery yet keeps them isolated.

Any battery - 6 volt or 12 volt -is just a box with battery cells hooked in series.

Big battery banks for houses run on solar more often use 6 volt batteries then 12s. My house has a 5400 watt solar array and a 48 volt battery bank. That 48 volt battery bank is composed of eight Rolls-Surette 6 volt batteries that are 9 years old and still working fine.

Here at my cabin in Adirondacks (where I am now) I have a 1000 watt solar array and a 12 volt battery bank made up of six 6 volt batteries that are low priced equivalents of Trojan T-105a. They are Deka GC2s that I got from NAPA 8 years ago for $55 each. At that time, Trojan T-105a were $90 each. Things have gone up since then but the Dekas are still a better buy.

If you can justify the cost, Odyssey makes the best battery I know of.Lots of power in a small package but heavy. They can be discharged complete and come back for more and handle a high amp rate charge as well. I have one application that I use Odyssey and many others with Optima. Don"t have to bother about corrosion with either.

You can switch over to all 12 volts and have as much or more power that"s reliable. And charge with any charger you want.
odyssey

http://www.theinverterstore.com/modified-sine-inverter-chargers.html

The PD with charge wizard will give good service.

I use a regular battery charger that has a low amp, deep cycle charge stage on it. I keep it hooked to the battery, plugged up and when we go camping it is on auto charge. It is the kind that will kick out when the battery is charged. That's a lot cheaper way to go than the camper converter/charger. Mine works great.

the bad external connections causing problems are a possibility. However when the internal connections of the batteries go bad you only replace on 6 volt instead.

The Telco central offices have worked for around 100 years on single cell batteries in series and worked fine.

I've owned RV's (too many to count, used to deal in them) for years and used plenty of those quasi deep cycle RV/Marine batteries like sold at Wal Mart and sure they work decent. But in my electrical engineers opinion (and RV experience) for RV use with a lot of fairly deep discharges (we do a lot of dry camping) a true deep cycle golf cart battery with heavy plates that is designed for maximum number of life cycles and deeper discharges IS FAR SUPERIOR TO THE CHEAPER RV/MARINE BATTERY. They will give you better service and longevity in my experience and study.

I think Trojans are over rated so in my current RV I used four of the higher capacity 230 Amp Hr Golf Cart batteries sold at Sams.

The cheap generic Converter Chargers sold in many regular priced RV's do fine to power your 12 VDC lights and vent fans and water pump and sure they will re charge your batteries BUT NOT NEAR TO THE QUALITY AN EXPENSIVE SMART 3 STAGE COMPUTER CONTROLLED TRUE CHARGER WILL. Ive seen too many cheap Converter Chargers overcharge RV batteries.

When I installed my four 6 volt Golf Cart batteries (460 total Amp Hrs) I wanted a quality smart computer controlled charger to maximize the life cycles and investment, so after I studied I chose a Xantrex Truecharge2 Charger. It, depending on battery state, starts out with Bulk Charge rate then switches to Absorption rate then finally Float Rate somewhere around 13.1 to 13.2 volts at maybe 2 amps trickle/maintenance. It also has an Equalization feature.

Soooooooo based on my years of experience and research and its my engineers opinion 1) For RV use sure, a quasi deep cycle RV/Marine battery will work, but for the long haul with a lot of deep cycle discharges and recharges a true full deep cycle Golf cart battery (heavier plates, designed for more and deeper discharges) IS MUCH BETTER but true can be more expensive. 2) A quality 3 stage plus Equalize computer controlled charger is also much better BUT THEY ARE INDEED MORE EXPENSIVE.

A friend of mine has the setup I used and got 9 years out of his batteries.

So your money your choice but a true deep cycle golf cart battery (if you do a lot of deeper discharges) will outperform and outlive the cheaper quasi deep cycle RV/Marine battery and, likewise, a quality 3 stage smart charger will outperform and extend battery life versus a cheap generic RV Converter/Charger.

PS to top it all off, I also added Solar Panels and a Solar Charge Controller. With that and my 460 amp hours of battery storage and an Onan Genset I can dry camp almost indefinitely wooooooooo hoooooooooooo

Best wishes n God Bless

John T

I used two Sam's club 6 volt golf cart batteries in my 5th wheel for over 6 years beach camping with no solor or generator. We usually spent 7 days at a time on the beach and they lasted well.

I slightly disagree.

The relatively cheap deep-cycle marine batteries made by Johnson Controls for Walmart at test to 100% discharges which is pretty unusual. I'm talking about the type 27s and 29s sold for electric trolling motors and not the "cranking" batteries.

No matter what battery you buy - the actual cost is how long it stays useful versus how many dollars you shell out. Any reputable battery maker will give info about any deep cycle battery in regard to how many 50% discharge cycles it can endure before it's worn out. Then simple math can calculate what is the best deal, dollar-wise.

If you pay twice the price for a Trojan and get twice the use - in some wayus it is no better then a cheaper battery that lasts half as long and costs half the price. Not unless you've got some real HD use in mind for an RV.

Where I live - there are no local Trojan dealers so shipping charges are added. NAPA sells the Trojan T-105 equivalents with no shipping charges and they are cheaper (or used to be). They are made by Deka, NAPA # 8143. I have a set in one of my RVs that lasted just as long as any T-105s I've had.

The down-side to golf-cart batteries is since they're 6 volt - you can yank them out of your RV when not used and put them into something else. I often use my 12 volt RV batteries and use them in diesel tractors in winter for starting. Kind of handy for that.

By the way - the Trojan T-105 "golf cart and scrubber" batteries are not considered true HD deep cycle batteries. The Trojan L-16s, yes.

The most HD deep cycle batteries made for long term use are 2 volts, not 6 volts and they often last 30 years. They also cost a small fortune.

One other issue. For somebody with an RV and running big draw applicances strictly off of batteries - and using an inverter - momentary voltage drop is a big issue. Most battery makers to not provide specs as to voltage drop versus draw. If running a big inverter, it really matters since inverters automatically shut down at 10.5 volts. Two Trojan T-105s hooked in series can only run a DC to AC inverter up to around a 1500 watt surge before voltage drops below 10.5 volts.

Outback is one of the few companies marking RV batteries with voltage-drop specs listed.

You are not saving anything by mixing old and new batteries together in the same circuit.
In fact you are increasing the chances of a battery explosion.

Any pair of good 6 volt golf cart batteries - hooked in series - give 12 volts and 225 amp-hours of power. If run to half-dead - they are built to last 1200 cycles before they are worn out. If run to 100% discharge they are supposed to last 400 cycles.

A pair of Walmart type #29 12 volt batteries, hooked in parallel give 12 volts and 190-210 amp-hours of power. If run to half-dead - they are built to last 700-800 cycles before they are worn out. If run to 100% discharge they are supposed to last 200 cycles (according to Johnson Controls tech).

They both do the same work. It's just a matter of cost versus longevity.

Thanks for the help guys.
The marine 12v battery I have is working great for now. I am putting my cheap battery charger on it a few hours a day to keep it charged till I decide what onboard charger to buy.

I understand the cost to A/H life of battery ratio. Paying $200 for a battery that gives you twice the life and same A/H as a $100 battery is no real savings.
Plus their is so much data to look at you could pull your hair out trying to dig threw all of it. Such as the Napa 8144. Good battery but is it the best choice when you consider A/H to dollars spent. For $5 more you can get the 8146 and gain 90 Min @25Amps.
Then you look at the Trojan T105 with its 1 yr. warranty. For about $30 more you can get the T105re with the same A/H's but a 5 yr. warranty because it is a better battery.

Way to much for my little brain to comprehend especially since this is a live in rather than a camping trailer for right now. We have no real use for more A/H of draw from the battery bank because we are plugged in 24/7.

What I am more worried about is how the plugged in 24/7 effects the battery and the charger I need to buy.
In other words does a battery work better if it is kept on a trickle charge all the time or unhooked from a charge every so often and allowed to discharge some.
I do not want the battery to overcharge because the charger is putting out more amps than we can use.
Or would it be better to just unhook the battery and run off the charger. How would that effect the life of the charger.

Since I can not find a charger that fills the battery and then shuts down till the battery gets to say 80%; then fully charges the battery again I guess I will have to live with a trickle charge 24/7 type of charger.

Once again thanks for the help.