cruz-in
Southern Maryland
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Hi Team,
Trying to decide on the last piece of my solar/battery upgrade.
Background:
1) I have 320+ watt of Solar on Roof
2) This is tied into a Morningstar MPPT controller
3) Charge controller is great and has programmable charge cvoltages and equalization
4) When we dry camp we use 70 to 90 AH per day.
5) I only have room for two batteries..
The question:
Would you choose:
1) 200 AH of 12 volt AGM (2 Exide MC-31 AGM 200 Megacycle batteries) OR
2) 310 AH of 12 volt Golf cart batteries (current battery of choice is US Battery 12 volt "sweeper" battery model US12V XC)
Considerations:
1) Both costs are basically the same
2) I have read (and been told by battery people) that AGMs can reliably be taken down 80%. So that gives us about 160 AH of useful power on the Exide AGMs
3) Using the often cited 50% figure for Lead Acid, That gives us about 155 AH of usable power for the US battery 12 volt "Sweeper" batterys.
So looking for input here. Which would you pick and why?
Thanks in advance for your time
* This post was
edited 05/02/12 06:38am by cruz-in *
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JiminDenver
Denver, Co
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Joined: 09/09/2011
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Not a battery expert,actually more of a question I guess.
You get the useable ah out of the AGM's by running them down 80%, They may do it reliably but are you getting 12v at that point?
My choice would be the higher AH battery. they give the same usable AH but stay above 12v doing it
2011 GulfStream Amerilite 25BH
2007/2003 Ford Expedition
Nights camped in 2011 21
Nights camped in 2012 16
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mena661
Southern California
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JiminDenver wrote:Not a battery expert,actually more of a question I guess.
You get the useable ah out of the AGM's by running them down 80%, They may do it reliably but are you getting 12v at that point?
My choice would be the higher AH battery. they give the same usable AH but stay above 12v doing it Great point about "getting 12V"! AGM's are typically "full" at 13V. What do AGM users get for voltage at 50%, 80%? I don't know. BTW, Trojan's and Surrette's can be takendown to 80% also (I'd imagine any good quality cyclable battery can be taken down that far). Like AGM's, you simply lose battery life. I'd always go for more capacity though.
If you haven't read it, check out my thread where I try to decide the same thing: Universal AGM's or Trojan 6V's
2009 Newmar Canyon Star 3205, Ford F53 V10
Trojan L16 6V's 740 Amp-hours
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smkettner
Southern California
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320
2001 F150 SuperCrew
2006 Keystone Springdale 249FWBHLS
675 watts solar
Send a PM if I missed something
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wa8yxm
Wherever I happen to park
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Let me put it this way... AMP HOURS are good things, you want as many of them as you can A:Afford and B arry.
Thus I'd go with the larger flooded wet cell bank.
AGM's do have an advantage in rough service, or service where they are not maintained "This side up" neither describes RV service..
SOME AGM's also can be more rapidly re-charged, but you do not have the ability to recharge them that fast so this does not apply either.
Flooded wet cells, if properly maintained, last longer, and cost less (As shown by your statment that 300+ amp hours worth of FWC's cost about the same as 200+ of AGM.. I'm surprised, AGM's are normally more expensive than that).
So I'd go for the bigger (Amphour wise) package.
Nothin adds excitment like something that is none of your business
Kenwood TS-2000 housed in a 2005 Damon Intruder 377
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3 tons
CA.
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Based on your daily power consumption (seems considerable though...), and the fact that solar is often variable, I'd choose the FWC's.JMO.
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cruz-in
Southern Maryland
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"I'm surprised, AGM's are normally more expensive than that)."
I can get the Exide MC-31 AGM200 Mega Cycle Group 31 100 AH battery for $169 and that includes core and tax.
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cruz-in
Southern Maryland
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3 tons wrote:Based on your daily power consumption (seems considerable though...), and the fact that solar is often variable, I'd choose the FWC's.JMO.
Power consumption includes some use of the heater during the night.
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recycler
michigan
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i'd go for the 310ah of lead acid myself
1968 franklin 11fk
back to my 93 cummins
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cruz-in
Southern Maryland
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Humm so no takers for the AGMs?
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