[RE-wrenches] battery cycle life, US Battery

Tue Sep 20 01:58:31 PDT 2011

Sorry, 2nd attempt. 

Could not attach the presentation but have if anyone is interested ........... 

Morning Wrenches, 

Regarding cycle life data, I thought some of you might find the attached interesting as it comes from a "Dankoff Dealer Training" in 04.  Allan, I know you were there but sure some others were as well.  As a supplier, those events were very enjoyable - probably not the same for the folks in the audience! 

If you scroll to the bottom of the "RE Product Line" section of our website, both cycle graphs are there for the flooded product from 20% - 100% DOD. 

http://www.rollsbattery.com/content/specifications-renewable 

The AGM data is in the FAQ section, will try and get this under the specs as well. 

http://www.rollsbattery.com/content/agm-faqs?q=node/81&phpMyAdmin=0610e516bf803196b5feee0b1ad65c08&phpMyAdmin=3jSJ-jdC5E7b53DHgV8TGvpSCF6 

Hope this helps, 

Jamie 

>>> Ray Walters <ray at solarray.com> 9/17/2011 5:38 PM >>>
Geez, I got that file on a model specific google search. It has a picture of a 4000 series flooded cell to the side, no other labeling, and it matched my cross check in the AEE catalog (1000 cycles at 50% DOD). I can't seem to get to that page within the website.....
The chart you sent is labeled series 4000, and is labeled 1280 cycles @50% DOD (very definitive, very different). Did both myself and AEE indeed use the wrong data?(I see the AGM tag) I have another s460 spec sheet claiming 1300 cycle 10 year life with no DOD mentioned.....
Its like shopping for tires or a mattress, you never know what to believe, other than real experience sometimes. I had a horrible time for instance finding cycle data for Deka, and I'm still not sure if what they sent is right (that Deka = Trojan) I had conflicting charts and numbers from Trojan too.....
Be nice to have an independent test facility and publish some trust worthy comparison data on a level playing field. I based my Rolls info on almost a decade of literature collected from them, not just that one chart.

Awaiting clarification from Rolls, sorry if I used the wrong data

Ray Walters

On 9/16/2011 10:57 PM, Allan Sindelar wrote: 

Default Title Ray,
You referenced the wrong chart. Yours was for AGMs. Try http://www.surrette.com/content/specifications-renewable.
Allan

Ron,
At 48V, I could be tempted to pick the 16 golf carts. Disadvantages: More cells to water and smaller reservoirs. More interconnects, more floor space. Advantages: More capacity for less money. More tolerance for abuse. About the same real-world cycle life (just based on experience). Lighter gauge and thus less expensive interconnects. And two strings isn't too many. Like Ray, I'm not too enamored of L16s as a value-based choice, although we use a fair number. We typically see 4 1/2 - 7 years from L16s, and about the same from golf carts.

Default Title Allan Sindelar
Allan at positiveenergysolar.com
NABCEP Certified Photovoltaic Installer
NABCEP Certified Technical Sales Professional
New Mexico EE98J Journeyman Electrician
Positive Energy, Inc.
3201 Calle Marie
Santa Fe, New Mexico 87507
505 424-1112
www.positiveenergysolar.com 

On 9/16/2011 8:37 PM, Ray Walters wrote: 

Here's the Rolls chart for cycle life:
http://www.surrette.com/content/agm-faqs?q=node/81&php
The cycle life is considered to be the point before the capacity begins being reduced.
I'm not seeing anything close to 800 cycles at 80%DOD. It looks like a typical L16, not over 500 cycles.
Are you using a different chart than what Rolls is posting on their website?

Ray

7 PM, Ron Young wrote: 

Hi All, 

Not sure where the 4 - 5 strings or more drifted into this conversation but the setup is basically in two strings of 16 GC batteries (48v) vs. 8 L-16 batteries in one string that I am recommending. With 7 year warranty for the Surrettes vs 1 year for the US Batt.; half the number of cells to water and check - and this is important as the maintenance on these 4 systems is being done by a third party who is not always reliably taking care of business; half the number of connections; half the footprint ...            

The only reason I can see someone recommending GC batteries in this scenario has to do with the company who set the systems up - Xantrex and their rationale seems to be the easy availability of the GC batteries e.g. in automotive stores etc. vs the more specialized distribution of the L-16's. Xantrex want to sell "arrive and drop" systems that will be sold through mass retailers from what I can see. 

The Rolls d.o.d. at 80% shows 800 cycles for the 4000 series batteries vs. 675 on the U.S. Battery chart but the U.S. battery chart doesn't differentiate between GC batteries and L-16's or any other type so I find it a bit suspect. 

Ron Young 

earthRight Products - Solareagle.com 

Alternative Energy Solutions ~ Renewable Energy Products 

On 2011-09-16, at 1:06 PM, RM You wrote: 

forwarded from earth2

Begin forwarded message:

From: Ray Walters <ray at solarray.com>
Date: September 16, 2011 1:03:43 PM PDT
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Subject: Re: [RE-wrenches] battery cycle life, US Battery
Reply-To: RE-wrenches <re-wrenches at lists.re-wrenches.org>

Larry,

I totally agree, that's a ridiculous # of batteries and strings. If that's really the case, it seems L16s will still need 4 to 5 strings, which is also crazy. I see only one solution to this battery bank, and that is the HUP or other large 2 v cell battery. Comparing golf cart batteries to L16s isn't even on the plate for good design in this case. For me, HUPs become a no brainer, as soon as the required amp hours gets into the 1000 AH or higher range. BTW, don't ever use the 100 hr rate for the Rolls, as they are way too optimistic. The 20 hr rates are much closer to reality. The Rolls S-530 becomes a 400 AH battery at the 20 hr rate, also they list cycles @50% DOD, when everyone else is looking at 80%DOD, be aware.
Here's some quicky math, with costs pulled off the internet:
3 strings of S530s (@24v) would get you 1200 AH for $4200. cycle life at 80% DOD about 450 to 500 cycles.
HUPs group 25 have 1270 AH and cost $7392, but last 2100 cycles to 80%DOD.
That's about 11.5 cents/ kwh for the life of the battery compared to about 29.2 cents/ kwh for the Rolls S-530s.
This quicky calculation doesn't even include the extra maintenance required for watering the L16 type battery, nor the fact that you will have 4 battery replacements for the same time the HUPs just have one replacement.
Its very fair to say that the HUPs are more cost effective by about a 3 to1 ratio.

Ray

 Having 6-8 parallel strings of golf cart batteries is a terrible idea no matter how much better the GC2 may be.

Larry 

On Sep 16, 2011, at 10:01 AM, Ray Walters wrote:
The real point is that the Xantrex guy is correct from a scientific stance. Experimental battery cycle life data shows that some golf cart batteries (T105) do have more rated cycles to 80%DOD than the Trojan L16. (750 vs about 600) A really crappy golf cart battery (some have cycle life below 400 cycles) isn't as good as an L16, yes. You have to base your decision, and your mouth, on test data for the batteries considered. Also, you must always compare at 80% DOD, for an apples to apples comparison. Its usually a clue if a manu doesn't publish their cycle life data. Of course you must temper the golf cart vs L16 decision with good paralleling technique.
We use golf cart batteries (never more than 4 strings), jump straight to the HUPs for larger banks, and skip the L16s all together. They just don't make sense when you look at the cost/ amp hr vs their lifespan.
The only time I could see using L16s, was if the battery bank requirements were beyond 4 strings of golf cart batteries, and the customer just could not afford the HUPs, or were going to sell the property soon, and wouldn't appreciate their long term value.
I've spent a lot of time looking at cycle life data, comparing costs, adding in maintenance and replacement labor, etc..
L16s are serious losers on a $/ kwh operating cost comparison, so this is a chance to up sell the customer to HUPs (or equivalent) and make both of you happier in the long run.

Ray Walters

_______________________________________________
List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Options & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:
www.re-wrenches.org/etiquette.htm

Check out participant bios:
www.members.re-wrenches.org

_______________________________________________

List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Options & settings:

http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:

www.re-wrenches.org/etiquette.htm

Check out participant bios:

www.members.re-wrenches.org

_______________________________________________

List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Options & settings:

http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:

www.re-wrenches.org/etiquette.htm

Check out participant bios:

www.members.re-wrenches.org

_______________________________________________

List sponsored by Home Power magazine

List Address: RE-wrenches at lists.re-wrenches.org

Options & settings:

http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org

List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org

List rules & etiquette:

www.re-wrenches.org/etiquette.htm

Check out participant bios:

www.members.re-wrenches.org

This email and its attachments have been scanned by iConnection E-Mail Firewall for viruses, spam, and malicious content.
The information transmitted in this email is intended only for the entity or person to which it is addressed and may contain confidential/privileged material. If you received this in error, please contact the sender and delete the material from any computer. Any review, retransmission, dissemination, or other use of this information by persons or entities other than the intended recipient is strictly prohibited. %^^%
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20110920/b4c36333/attachment-0003.html>