[RE-wrenches] Two sealed battery questions, please

Allan Sindelar allan at positiveenergysolar.com
Mon Nov 12 14:55:00 PST 2012


Wrenches:
First question: for a large grid-tied with battery backup system (9.8 kW 
array, two SB5000s, dual Sunny Islands), we have offered the customer 
the choice of either one 48V string of 24 2V Concorde SunXtender 
PVX-121HT, for 1,200 A/hr, or a set of Absolyte GP 100G23s, for 1,260 
A/hr (at the 20 hour rate), the closest match. The prices, surprisingly, 
are quite close - the Absolytes are a bit less expensive, given the 
additional cost of battery enclosures and labor for the Concordes. I 
have avoided recommending one or the other on the basis of battery 
service life, as we haven't enough experience with the Absolytes. The 
question: which of these battery options would you recommend to the 
customer, and why?

Second question: Four years ago, well before we got involved, the 
customer purchased a 24V set of used Absolyte IIP telecom batteries and 
we agreed to incorporate them into this system. I contacted Direct Power 
on their behalf to inquire about obtaining a second 24V set of batteries 
to add to their set of 3-100A33s to make a 48V bank. I learned that they 
have no more of these sets in stock and have no firm expectation at 
present of getting any more. I had asked here about finding a set and 
about mixing new with old but received no responses.

We will be going with a new set of batteries, either Absolyte or 
Concorde. This leaves the old set up for resale. But in the process we 
learned via the date codes that the customer's set was eight years old 
when he got them, and have been in their possession unused in a barn 
since then. See below for the customer's description of them. The 
question: what is the expected remaining life of these 12 year old 
cells, assuming the best - that they were left fully charged and in 
float for eight years and seldom if ever cycled? What might they be 
worth today, if anything?

Thank you,
Allan


-------- Original Message --------

Hi Allan,
Here is that note regarding batteries. I have 4 Absolyte batteries 
manufactured in 2000, model # 589 508  kkc 7667,7668,7670,7674. They 
have been used for back up in the telecommunication field. I have owned 
them since 2008 and they have been float-charged on a monthly basis to 
keep them topped-up. I think their condition is good--- although I have 
not load-tested them. They were purchased for a project that is no 
longer in play and so I would like to pass them along.
Ted




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