Deka DC31DT battery? Deep Cycle?

DiskDoctr wrote:
2. I have the WF-8955AN 3 stage charger at 55amps ...

And there's your biggest issue ... probably wired with way too much 6 gauge to get to the battery location and almost for sure never bulk charges at it's advertised 14.4 volts. It's the same problem I and just about every other WFCO owner has :M ... I solved mine by turning the darned thing off and instead using a portable charger that does do a proper 14.4 volt bulk charge and is wired directly to the battery with 6' of 4 gauge.

Fact is, charger and battery are directly related - buy a Trojan and you're going to want to bulk charge at 14.8 volts, buy a Deka AGM and you'll want temperature compensated charging which almost no converter / charger is capable of. Getting the most out of whatever batteries you buy isn't just a matter of comparing battery to battery but also matching those batteries to the charger you intend to use to maintain them. Ignore it and you can bet you'll be replacing those batteries sooner rather than later. :(

Doc TMI

MEXICOWANDERER wrote:
For "Moon Mission" calculation...

Did you see my post? Sometimes I feel like we are planning for a Moon Mission, LOL.

I've been keeping a good eye to the weights of the batteries we are looking at.

Thanks :)

SoundGuy wrote:
...while the OP has been agonizing over which batteries to purchase he hasn't said a word about what charger he's using to maintain those batteries, which is critical if he expects to maximize the life of any battery he may invest in, particularly if he opts for AGMs or Gels instead of flooded

Well, been trying to work that out. Here is where the choice is at the moment, and key points.

1. Flooded batteries. Different chemistry and such would require other charging and higher voltages, which could affect my unregulated LEDs.

2. I have the WF-8955AN 3 stage charger at 55amps (load and charger)

3. We will be out up to a week at a time without shore power, but will have generator use a few hours a day.

4. We have Xantrex 1800 PSW inverter on its way to run 120v lighting and laptop power supplies, and likely try running microwave a few mins each am during quiet hours.

5. Strongly considering Group 31 12v deep cycle batteries, expecting to have 2, possibly 3 in parallel.

6. We will plug in the camper for an extended period when we return from the week+ trip, then a day or two at a time while on the 2-4 week travel trip to different places this summer.

7. I DO have several large chargers that can be used when we return home. Some are multistage, some are not. Most are not easily portable, but I have a 3 stage dual battery charger in the boat that may come out...not all worked out yet.

8. As inverter is direct wired and we move the converter to its own breaker and add NC relay to prevent it from being powered on inverter, and we likely add 30amp transfer switch (the built in ATS on the inverter is only 15amp, probably have to just skip it) to jump between shore/generator power and inverter power.....leads to....

9. A starter solar system could show up by the end of season or before next season, with appropriate charging upgrade that will top off the batteries.

As the system "matures" we are striving to take steps that meet our needs and expected needs without too much waste or replacements necessary.

10. We are adding 12v sockets and USB ports to natively power and charge devices without the inverter

11. I will be moving the cell wireless repeater/booster to this new camper and strategically placing the Mobley that just arrived today to allow my daughter to take her advanced classes this summer while traveling.

12. We *may* provide for the ability to isolate one battery as emergency use for the newly installed electric tongue jack and both 12v slides.

13. I'll be building extra battery mounts for 3-4 batteries.

14. The inverter will be mounted inside the front storage area on the soon to be added pegboard to line the full width compartment, while I pull the LCD monitoring panel, wire in RJ45/RJ11 (not sure which it has) to remote the panel to as of yet undetermined location to monitor, but provide the ability to cover it to shade at night in the master bedroom.

15. Replace the ceiling vent fan in the bathroom with a Fantastic Fan, after washing and resealing the entire roof, slides, sides, etc.

16. Replace the awning

17. Devise rear storage container rack setup and try to fit in all our gear

18. Work out a bike rack, possibly with a front hitch on the Excursion

19. Wash and wax the camper ( :) )

20. Paint any faded plastic, replace all window weatherstripping while cleaning and dry lubing the contact points and sliding channels

21. Finish replacing the cooling unit on the fridge and reinstall it, while making new air chimney/draft above the fridge and allowing for a new storage area above it.

22. Add LED lighting to underside near wheels and stabilizing jacks for night time setup

23. Add backup cameras to Excursion and to the camper

24. Add expansion tank to water system

25. Add quick disconnect to propane system for our Wave 3 propane heater

26. Add light switches inside the door and lights to steps

27. Add extended grab handle to steps/door

28. Replace stove hood vent fan with quiet and efficient fan

29. Possibly add fan to main bedroom vent

30. Add vent hoods (like MaxAir or similar) for powerless ventilation

31. Flush, test, and sanitize water and waste systems.

32. Pull all wheel hubs to inspect and pack bearings and inspect brakes

33. Shampoo all carpeting and wipe down entire camper walls, ceiling, cabinets, etc

34. Figure out where to pack everything we take with us

35. Do service and maintenance on our hybrid to get it ready to sale.

...and probably lots more, LOL

So you can see that batteries and power are very important, but lots of other moving pieces as well. If I miss a few things or make some mistakes, please point them out, but don't get too frustrated with me- lots of things happening and being planned :W

I guess this is all part of coming from a camper we spent years modding and setting up just the way we wanted and then starting over with another camper. Exciting for sure! (but also a lot of work)

Keep the tips and info coming. They are HUGE helps :)

Thanks!

For "Moon Mission" calculation, twiddling down to the least significant digit may be warranted. But I know of few campers who construct Prussian grade rigidity with regard to camping and battery management.

Compare weight and posted performance to competitive batteries to gain an idea of what's beneath the plastic of your choice. Heavy weight, low ampere hour rating, and CCA could demarcate.

It pays to keep in mind, thick plates mean one significant point: More allowance for additional allowable plate shedding and corrosion etch. This revolves entirely around whether a battery is constructed well enough and taken care good enough to let the thicker plates aspect come into play.

MrWizard wrote:
The problem is numbers and the way they are expressed.

For comparison purposes between different makes / models of batteries the 20 HR rate is the most commonly used and as valid as any. However, anyone who takes that 20 HR rate and automatically assumes that simple math will tell them exactly how long the battery will last when drawn down to 50% SOC will be sorely disappointed as no battery will deplete in a linear manner but will vary considerably as the total load varies. Interestingly, while the OP has been agonizing over which batteries to purchase he hasn't said a word about what charger he's using to maintain those batteries, which is critical if he expects to maximize the life of any battery he may invest in, particularly if he opts for AGMs or Gels instead of flooded. :R

The problem is numbers and the way they are expressed

105 ahr at the 20hr rate that's a solid number but it also means 5 amp discharge for 20 hrs

225*23 is a reserve minutes number, 23 amps (not 5 amps) for 225 minutes aka 3 hrs 45 minutes ( not 20 hrs )

Which is less amp hrs total you are using power at almost 5 times the 20hr discharge rate, it's called peurkut effect, the chemical reactions of the battery are less efficient producing the electrical energy

Yes both numbers can be valid for the same battery, because they mean two different things

DiskDoctr wrote:
Now I'm REALLY having trouble reconciling the "20 amp hour rate" of the GC2 vs Group 31 :h

Seems to me you're going to great effort to confuse yourself :R ... neither of these batteries you've mentioned are AGM but rather conventional flooded. As I already mentioned that Group 31 DC31DT Duracell branded battery is actually a Deka manufactured by East Penn and is the exact same battery sold by East Penn here in Canada as an RV Care Traveler's Choice battery, 20 HR rated @ 105 AH, 210 AH for a pair wired in parallel. GC-2 Duracells are likewise East Penn Dekas, also sold here in Canada as the RV Care Traveler's Choice PS2000, 20 HR rated @ 215 AH each and therefore 215 AH for a pair wired in series.



Between these 2 choices I wouldn't be worrying about a mere 5 AH difference but rather which ones (Group 31 or GC-2) would best fit where you intend to locate them on the trailer. Secondly, if your intention is to regularly deep cycle these batteries then you'd probably be better served with a pair of GC-2s which are designed for this purpose. Alternately, if you anticipate deep cycling your batteries only occasionally but do expect them to regularly tolerate heavy inverter load then you're probably better off with a pair of Group 31s as they're more likely to suffer less voltage drop under heavy load than will a pair of GC-2s.

MrWizard wrote:
That battery is approx 80 amp hrs
The first number 225*23 gives 86 amp hrs
The second number 185*25 gives 77 amp hrs per battery
Less then 200 amp hrs per pair
Quite a bit less than two golf car batteries at 220~230 amp hrs

Hmm...

The GC-2's he said were 205@20amps.

I have both Deka and Crown written down, so not sure which was the initial answer and which one was after he checked.

The GC-2 number by your calcs would be substantially lower than the 205/215 ah that I've heard people quote for the Duracells.

According to the Sams Club page for the Duracell GC-2

Description Member reviews & questions Policies & plans

Description

For applications that requires deep-cycle power, this is the battery of choice. Use it in your personnel carrier, aerial lift, electric vehicle, golf car, boat, RV, floor scrubber, or road sign. The biggest innovations lie inside the battery, where we use heavier grids, plates with higher density oxide and improved glass mat envelope separators. The result? Longer life cycles and superior cycle-life performance. The exterior features represent powerful thinking as well. Engineers have designed a battery that is as durable and user-friendly as possible. The heavy-gauge polypropylene cases have been specially engineered to take a pounding without damaging the cells. Twist-and-release vent caps make removing caps a snap, and we’ve maximized convenience by designing a new lifting system.

Specifications

20 amp hour rate:215
5 amp hour rate:157
6 amp hour rate:156
Battery Electrolyte Composition:Acid
Battery End Type:Top Post
Battery Purpose:Deep Cycle
BCI Group Size:GC2
Contents:ONE EACH
Freight Class:65
Minutes at 25 amps:395
Minutes at 75 amps:105
Terminal Type:DIN
Volts:6

Now I'm REALLY having trouble reconciling the "20 amp hour rate" of the GC2 vs Group 31 :h

(I don't recall the exact thread title, but it is the one where folks speculating the Duracell is the rebranded Trojans at Costco)

GordonThree wrote:
the 2x GC2 for $170 aren't AGM for that price, or yes, they're a good deal. I paid 179 ea for my G31AGM from sams, where are you seeing them for 120 ea?

Found them at local Battery Warehouse. I didn't find them on their website, but called up. Been dealing with them for a few years, always has something interesting around or can order.

I am NOT certain about the model, though, will have to wait until tomorrow to call back.