[RE-wrenches] battery cycle life, US Battery

[toddcory at finestplanet.com]

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" <ray at solarray.com> 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





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