What about the 2 volt L-16 versions? Has anyone had success with them for
larger banks? I work alone and HUPs are too heavy to lift on my own... however
24, L-16's in one series string would be a hell of a battery bank too.
Todd
On Friday, September 16, 2011 1:03pm, "Ray Walters" <[email protected]> said:
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
Sent from Finest Planet WebMail.
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