[RE-wrenches] battery cycle life, US Battery
Ray Walters
ray at solarray.com
Sat Sep 17 13:38:03 PDT 2011
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:
> 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.
>
> *Allan Sindelar*
> _Allan at positiveenergysolar.com_ <mailto: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_ <http://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 <http://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 <mailto:ray at solarray.com>>
>>>>> *Date: *September 16, 2011 1:03:43 PM PDT
>>>>> *To: *RE-wrenches <re-wrenches at lists.re-wrenches.org
>>>>> <mailto: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
>>>>> <mailto: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
>>>>>
>>>>>
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