AGM's maybe not so great???

[John From Detroit]

I will support NED here.  For the same group size you may find CCA 1,000 AH as low as 20,  CCA 500  AH 40  CCA 200 AH 100

Note all numbers are "Thin Air" numbers, not intended to be real, only examples of what we are trying to say

I don't care how "Deep Cycle" it is, it still has a cold cranking rating... Iti's just that while a group 24 starting battery may well crank up a good size truck, a Group 31 DEEP CYCLE may only crank up a medium size motorcycle.

Ok, Group 27 for the truck

 

[Friendship8380]

http://www.trojanbattery.com/Products/ProductSpec.aspx?Name=J150

these are the batteries i've been looking at. it doesnt say if its agm or what... does anyone have experience with this j150? mine need replacing now, they are shot, but i dont want to jump into a battery at these prices without knowing some good experiences with them. this is way to important decision to be made by a newbie like me... :-\
p.s. i will be dry camping about 1/2 the time...

 

[Ned]

Although Trojan does make some AGM batteries, the J-150 isn't one.  It's a 12v deep cycle battery with a 150AH rating.  A more typical RV installation uses 2 T-105 or T-125 Trojans, 6v deep cycle batteries with AH ratings of 220AH and 240AH.  Check prices and compare a pair of J-150s with a pair of T-105s or T-125s.  The J-150s will give you 300AH of capacity but take more room.

 

[Gary RV_Wizard]

Every battery has a CCA rating but that doesn't mean they're designed for starting service.

OK, how about this quote from the Lifeline RV battery Intro page?  Lifeline RV Batteries

# LIFELINE RV BATTERY BENEFITS User Safe
      sealed construction
      non-spillable
      install in any position if properly supported.
      submersible without damage
# Maintenance free (no adding water or repairing corroded terminals)
# Fastest recharge. (no current limitations with voltage regulated recharging)
# Deep Cycle (thick positive plates to provide real deep cycle performance)
# Outstanding cranking performance (aircraft cell construction lowers internal resistance)
# Best charge retention (especially against flooded cell types)
# Lowest discharge rates (Less that 3 percent per month unattended)
# Easily shipped (even via UPS except GPL-8D and GPLAD because of weight)
# Shock and vibration resistant. (100% of plates are covered with separator liners)
# Properly supported, LIFELINE AGM batteries with absorbed electrolyte can be installed and operated on their side.

{Bold print added to highlight the key phrase}

That's the exact same list of benefits as is shown on the marine starting & deep cycle battery page, for the exact same list of Lifeline battery models.

And a Lifeline GPL-24T has a CCA rating of 550A at 0 degrees, which is not a trivial number for a size 24.

 

[Ned]

Well, I guess AGMs can do it all then

 

[Phil]

And a Lifeline GPL-24T has a CCA rating of 550A at 0 degrees, which is not a trivial number for a size 24.

AGM batteries are true deep cycle batteries and they have a very low internal resistance compared to other deep cycle batteries.  That's why they have a high CCA rating compared to other true deep cycle batteries.  The low internal resistance also makes them easy to charge.  The main drawback for AGM batteries is the cost.

Phil
 

 

[Gary RV_Wizard]

Well, I guess AGMs can do it all then

Well, the Lifelines claim they can. I'm not so sanguine about other brands of AGMs.

I concede that CCA ratings for AGMs are not as high as for gels, wet cells etc. of similar case sizes. The CCA numbers I see for Group 31 AGMs are in the vicinity of 575-600 amps and a Group 31 wet cell or gel is more often in the 900+ range.

 

[Ned]

At least Lifeline publishes all the data on their batteries.  I don't know if other manufacturers do so as extensively as I've never considered any others.

In the RV application, I can't see buying AGMs for starting batteries when sealed batteries like Interstate are available in higher capacities for much less money.  I can see the advantage in applications like aircraft or marine where the mounting flexibility would be a big plus.

 

[ArdraF]

Just thought I'd add my two cents worth.  We ordered AGMs with this motorhome.  Monaco wasn't even putting them in at that time (2002-3), so we were their first.  We've been very pleased with them and have no complaints.  I like it that Jerry doesn't have to fiddle with something acidic all the time.  Sure is better for his clothes!  ;D

ArdraF

 

[Gary RV_Wizard]

In the RV application, I can't see buying AGMs for starting batteries when sealed batteries like Interstate are available in higher capacities for much less money.

I agree - and the OEM chassis batteries in our Tradition are Group 31 maintenance-free wet cells. Not even gels - just sealed wet cell Interstate Workaholic 31MHD's with a 950A CCA rating.  I load tested them and they still rate OK after three years, which seems like pretty decent service to me. I'm not a fan of Interstate products, but these seem like decent quality. They are designed for medium & heavy duty trucks & heavy equipment, not standard automotive use. The 195 minute RC rating isn't too shabby either, but with 120 plates (vs the 40-60 of a typical golf cart battery) it clearly is designed for starting rather than deep-cycling.

 

[Ned]

Our motorhome came with 2 Freightliner branded starting batteries, sealed, no maintenance, probably Interstate.  We replaced them after 9 years, even though they were still turning the diesel over with no problem, only because we were heading to Alaska last summer.  If only house batteries would last that long

 

[Friendship8380]

i went to trojans website to find local dealers and they dont stock the t-105 or the t-125. they would have to be ordered and it will take 4-6 weeks. one that was listed as a dealer said they have never sold trojan batteries... ???

where else here in central florida should i try?

 

[Ron]

You might check with places that sell and service Golf carts.

 

[Ned]

Also check with any alternative energy (solar and wind power) companies.  They will have a selection of deep cycle batteries.

 

[ArdraF]

You might check with places that sell and service Golf carts.

Ron's right.  A few years back we had a problem with batteries while in Death Valley.  The guy who services their golf carts told us to go to a place in Las Vegas where their entire business is golf cart batteries.  He said their volume is so high that we would be sure to get "fresh" batteries there.  The fellow installed them and the price was quite reasonable, although I don't recall what it was.  I guess if you're in an area with a lot of golf courses you could find someone like that.

ArdraF

 

[Friendship8380]

well, i got my new trojan t-105's in today. it took a little more time because they're so much taller, but they fit. $87.00each...

 

[Karl]

Wow! That was a good price! Did you have to wait by a pay phone for directions on where to pick them up? ;D ;D