Go Back   iRV2 Forums > MOTORHOME FORUMS > MH-General Discussions & Problems
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
 
Thread Tools Search this Thread Display Modes
 
Old 04-29-2010, 09:31 AM   #1
Senior Member
 
fkloster's Avatar
 
Vintage RV Owners Club
Join Date: Jul 2009
Location: Beaverton, OR
Posts: 236
A battery with 475 minutes @ 25 amps reserve?!?!

PC1800 Odyssey Battery - Odyssey Drycell Batteries

I guess if batteries for your big RV is the question.... the question is answered here!

I checked on pricing.... : Monster PC-1800 = $575.73 a piece.... (1,300 CCA with 475 minutes reserve @ 25 amps?! wow!

PC-2150 group 31's = $341.24
PC-2250 8D's = $448.74
__________________

__________________
fkloster = Fritz, Erin, Sadie, Bo (& Lucy the Weim)
1991 Beaver Marquis 40' (1,225 ft. lbs. torque)
2011 JGC Overland Summit Toad / U.S Gear Brake
fkloster is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 04-29-2010, 10:24 AM   #2
Moderator Emeritus
 
Gary RVRoamer's Avatar


 
Join Date: Jan 2000
Location: Silver Springs, FL. USA
Posts: 18,085
That's similar to the L16 case style which is often used in off-grid solar systems, but a bit taller, with capacity to match. Capacity spec is about the same as an 8D, which Trojan makes in an AGM as well. The 8D is good if you have plenty of width but little height, whereas this one is good if you have height by a narrow space.
__________________

__________________
Gary Brinck
Former owner of 2004 American Tradition
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC
Gary RVRoamer is offline   Reply With Quote
Old 04-29-2010, 11:41 AM   #3
Senior Member
 
Join Date: May 2007
Posts: 632
interesting that the energy density is a bit low - 2568 watt hours for 132 pounds is a bit under 20 watt hours per pound. That figure gets closer to 22 - 25 for most RV batteries.

This also gets interesting because it hits the 'thick plates' deep cycle myth - "Odyssey is the only manufacturer that utilizes pure lead, flat plate technology in the construction process. This allows for more lead plates in a smaller area, exposing more lead to acid and creating a greater power density than any other brand." -- that particular bit of hype has some interesting contradictions and implications to think about.

The 6-10 year service design life is about on a par with other AGM type batteries. They claim superior deep discharge performance but I note that their 'technical guide' does not offer any data on that.

The web site could be a good resource for those interested in studying advertising hype. One should be very very careful in qualifying what is being said by looking for actual specification and measure to support the claims.
__________________
BryanL is offline   Reply With Quote
Old 04-29-2010, 12:15 PM   #4
Senior Member
 
fkloster's Avatar
 
Vintage RV Owners Club
Join Date: Jul 2009
Location: Beaverton, OR
Posts: 236
Quote:
Originally Posted by BryanL View Post
interesting that the energy density is a bit low - 2568 watt hours for 132 pounds is a bit under 20 watt hours per pound. That figure gets closer to 22 - 25 for most RV batteries.

This also gets interesting because it hits the 'thick plates' deep cycle myth - "Odyssey is the only manufacturer that utilizes pure lead, flat plate technology in the construction process. This allows for more lead plates in a smaller area, exposing more lead to acid and creating a greater power density than any other brand." -- that particular bit of hype has some interesting contradictions and implications to think about.

The 6-10 year service design life is about on a par with other AGM type batteries. They claim superior deep discharge performance but I note that their 'technical guide' does not offer any data on that.

The web site could be a good resource for those interested in studying advertising hype. One should be very very careful in qualifying what is being said by looking for actual specification and measure to support the claims.
Heavier batts because the plates are constructed of pure lead?
__________________
fkloster = Fritz, Erin, Sadie, Bo (& Lucy the Weim)
1991 Beaver Marquis 40' (1,225 ft. lbs. torque)
2011 JGC Overland Summit Toad / U.S Gear Brake
fkloster is offline   Reply With Quote
Old 04-29-2010, 01:28 PM   #5
Senior Member
 
Join Date: May 2007
Posts: 632
re: "Heavier batts because the plates are constructed of pure lead?" -- higher weight density, to be precise. Lead that is inside a solid plate is not available for reaction with the electrolyte so it just adds weight without contributing to energy storage capacity. The website claims thin plates (high surface to volume the thinner the plate) to circumvent this which is rather funny because some of the 'true deep cycle' advocates insist you need thick plates for deep cycle batteries to make them strong and handle many cycles.

For the careful reader considering the claims and implications, a high degree of skepticism is warranted about the claims made. The idea of using pure lead in foil or plate form has many problems.

One of the improvements in modern batteries is how to construct plates such that a higher percentage of the lead in the plates can interact with the electrolyte. That is related to methods to increase the reaction surface area for large short term current capabilities.

Note that no lead acid battery does well with deep discharges (down to 80% SoC). Running your battery down that far as a regular thing is a sure path to a short battery life.
__________________
BryanL is offline   Reply With Quote
Old 04-29-2010, 01:54 PM   #6
Senior Member
 
fkloster's Avatar
 
Vintage RV Owners Club
Join Date: Jul 2009
Location: Beaverton, OR
Posts: 236
Quote:
Originally Posted by BryanL View Post
re: "Heavier batts because the plates are constructed of pure lead?" -- higher weight density, to be precise. Lead that is inside a solid plate is not available for reaction with the electrolyte so it just adds weight without contributing to energy storage capacity. The website claims thin plates (high surface to volume the thinner the plate) to circumvent this which is rather funny because some of the 'true deep cycle' advocates insist you need thick plates for deep cycle batteries to make them strong and handle many cycles.

For the careful reader considering the claims and implications, a high degree of skepticism is warranted about the claims made. The idea of using pure lead in foil or plate form has many problems.

One of the improvements in modern batteries is how to construct plates such that a higher percentage of the lead in the plates can interact with the electrolyte. That is related to methods to increase the reaction surface area for large short term current capabilities.

Note that no lead acid battery does well with deep discharges (down to 80% SoC). Running your battery down that far as a regular thing is a sure path to a short battery life.
These appear to be "AGM" batts though... does that matter?
__________________
fkloster = Fritz, Erin, Sadie, Bo (& Lucy the Weim)
1991 Beaver Marquis 40' (1,225 ft. lbs. torque)
2011 JGC Overland Summit Toad / U.S Gear Brake
fkloster is offline   Reply With Quote
Old 04-29-2010, 07:27 PM   #7
Senior Member
 
Join Date: May 2007
Posts: 632
re: "These appear to be "AGM" batts though... does that matter?" -- I don't think so but then I haven't taken apart one of the batteries and aren't that far into the picayune details of manufacturing and design. (it might be fun but isn't really relevant to buying RV batteries, IMHO)

The basic concept of volume to surface area ratio is still something to consider. There is also the fact that it takes a few cycles to realize a battery's full capacity because its plates need to etch to provide more exposure and the implications of that on various plate structures.

The key issues are to look at the actual measures such as expected life (usually, warranty is the only reliable indicator for this), capacity, size, and cost. Then you don't want to get lost in detail that doesn't contribute to your goals.
__________________
BryanL is offline   Reply With Quote
Old 04-30-2010, 09:37 AM   #8
Moderator Emeritus
 
Cruzer's Avatar


 
Join Date: Oct 2002
Location: Sheboygan, WI
Posts: 4,902
Flooded batteries don't fare well when discharged below 40-50% of capacity. It really cuts into their lifetime. So, when using a typical 220 amp-hr battery you should only plan on using about 110 A-H of capacity before recharging.

But, that's not based upon percentage. What it is based on is voltage drop. It just happens that that voltage level arrives at just under 50% on a flooded battery.

AGM batteries are different than flooded. The do not have flooded electrolyte cells. The electrolyte is wrapped in glass mats around the plates therefore they do not outgas any hydrogen like flooded cells do. They also have less internal resistanace so they take a charge faster. That same cell design allows the batteries to run longer than flooded batteries before they get to that critical voltage dropoff point. If you plot the voltage drop over time on a graph you would see a flooded battery curve down fairly quick while an AGM extends out farther and flatter. The end result is that you will get about 30% more runtime from an AGM battery than a flooded battery of the exact same rating. I've found that converting to AGM batteries is just like getting 30% more batteries for free. Well, not exactly "free" because they do cost more. But they take up the samespace as flooded so in that regard you gain capacity. They also last longer than flooded so some of that initial cost is recovered over time.
__________________
Mark & Leann Quasius
2016 Cornerstone 45A
2007 Allegro Bus 42QRP (Sold)
2012 Jeep Wrangler Unlimited - Rubicon
Cruzer is offline   Reply With Quote
Old 04-30-2010, 11:20 AM   #9
Senior Member
 
Join Date: May 2007
Posts: 632
An AGM battery is a lead acid battery with the electrolyte contained in a glass mat. It will outgas like other lead acid batteries if overcharged. Being sealed, it is sensitive to overcharging because of this.

The life of an AGM battery is reduced when you deep cycle it just like any other lead acid battery. The curve for number of cycles versus depth of discharge is similar to other lead acid batteries.

While an AGM does have a lower internal resistance than other lead acid battery types and also a lower self discharge rate, it won't provide you more energy for "free." The energy density by weight (or volume) is about the same as is the Peukert coefficient.

From the NAWS FAQ, the indications are that you can expect up to a 50% longer life from an AGM but this depends a lot on use profile, maintenance management, and other factors.

AGM's are lead acid batteries. They are just constructed a bit different from your usual wet cell batteries or other sealed lead acid types. The differences are minor in the context of other things that influence batteries of this chemistry.

AGM's are nice batteries, but, please, let's use actual reliable measure and avoid anecdotal hype.
__________________
BryanL is offline   Reply With Quote
Old 04-30-2010, 12:00 PM   #10
Moderator Emeritus
 
Cruzer's Avatar


 
Join Date: Oct 2002
Location: Sheboygan, WI
Posts: 4,902
Sorry, I guess my 30% longer runtime was based on my actual experience rather than an engineering paper.

Yes, it is a lead-acid battery. Never said it wasn't. It's not a flooded battery, as I stated. For all practical purposes AGMs do not outgas. Yeah, if you want to get technical they can under extreme conditions, such as over-volting, but for practical purposes you can place them anywhere you need to in an RV without fear of hydrogen gas expoding.
__________________
Mark & Leann Quasius
2016 Cornerstone 45A
2007 Allegro Bus 42QRP (Sold)
2012 Jeep Wrangler Unlimited - Rubicon
Cruzer is offline   Reply With Quote
Old 04-30-2010, 01:17 PM   #11
Senior Member
 
Join Date: May 2007
Posts: 632
re: "based on my actual experience rather than an engineering paper." -- no need for this IMHO. You have a valid experience but it is only one sample with many unknown variables. The NAWS FAQ is based on very many samples and reflects a variance that acknowledges the influence of the variables involved. (it isn't an "engineering paper" either but rather a vendor's experience.) Warranties are a manufacturer's promise and that can be a good guide as well for longevity.

Code does not distinguish AGM's from other batteries as far as battery boxes and proper ventilation. There are reasons for this.

AGM manufacturers warn about charging voltages and such things as equalization. There are reasons for this as well.

The lesson is that we need to be careful in extrapolating one or two experiences (including our own) by realizing that they are only a very small part of the entire picture.
__________________
BryanL is offline   Reply With Quote
Old 04-30-2010, 01:27 PM   #12
Senior Member
 
Gary - K7GLD's Avatar
 
Join Date: Aug 2009
Posts: 1,696
WELL, nice thing about the battery in the lead post, is that with proper leads, you also have a nifty on-board welding setup at your disposal...
__________________

__________________
John Day....|'88 Winnebago Super Chief 27ft. Class A
Eastern .....|'88 KIT model 240 24 ft. 5er
Oregon ......|'02 Dodge/Cummins 2500 Quad Cab
Gary - K7GLD is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Installation of Chassis Battery Bus Bars - Journey 36G SteveG Winnebago Industries Owner's Forum 10 03-31-2009 08:08 PM
Toad Battery Charger Installation Question IBHIPRU2? Winnebago Industries Owner's Forum 4 03-27-2009 07:40 PM
Bad Chassis Battery ? tazsport Winnebago Industries Owner's Forum 5 11-26-2007 01:01 PM
Installation of a Battery Disconnect Switch SteveG Winnebago Industries Owner's Forum 7 07-09-2007 07:53 AM
chassis battery problems tallguy Workhorse and Chevrolet Chassis Motorhome Forum 12 10-08-2006 10:53 AM

» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 09:24 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.