Yeah, and hence not using them anywhere near what was originally envisaged. If they were, my bet is they would not last long. (Under your original conditions, you would have had to recharge them externally after every use (else engined with audio down or off), not once a month.)
But keep in mind that the 100AH rule is not a ROT - it is a rule
that seems peculiar to floridaSPL only, though by now it will no doubt have spread. I could probably start an equivalent rule of 10AH per kW, or 1,000AH per kW, and double those for wet cells or gels.
I still reckon it is a misquote or misunderstanding of the variously used 12V rule of "100A per kW
" - ie, as a simple guestimate
of current, or a design-safe estimate of load current, or an approximation for fuse (or cable) ratings and converting output
power to input
power currents (ie, assuming ~80% fuse or cable rating margin, or ~80% amp or equipment efficiency). But the 100AH per 1kW ROT
has many more variable attached to it (eg, battery size, ESR, charge state, temperature, age).
Just be careful if specifying standby batteries for audio and cyclic use. If they are truly needed and discharge regularly, they probably won't last long.
[ Getting back to your original "batteries are batteries
" comment, they aren't. With some batteries being 1/10th the price of others, money hungry companies and misers like myself would be sure to use them. But trust me, cranking batteries used for solar (or vice versa) are unlikely to last long. And industrial UPS would be using ordinary batteries too (though some UPS batteries may only last 5-10 cycles, but they are more stable/reliable and smaller).
A similar situation exists with ordinary domestic batteries - cheapies may last longer than alkaline, or as I found, those $5 Lithium 680+
AA & AAAs are far cheaper
than using 20c-$2 substitutes in cameras. ]
And as you are probably aware, if using low ESR AGMs with thumping hi-powered audio systems with higher than a few kW output, caps of 1F or more will probably extend the life of the AGMs considerably. (Wet cells do not suffet the same problem. As I oft write, AGMs may be capable of supplying high currents, but they don't like it.)
That - apart from battery time lags (and ignoring surface charge) - is probably the only legitimate application for caps in quality audio systems.
FYI - I often refer people to Bill Darden's BatteryfFAQ
- IMHO an excellent & well written reference - everyone should read at least 1. WHAT IS THE BOTTOM LINE AND TIPS?
It's a relative easy read considering the complexities with IMO the most useful section 9 being the only big section.
I suggest downloading as per 9. HOW CAN I PRINT THIS FAQ?
, and maybe checking every few months for the occasional update.
But you should find that I write agrees with Bill, though that detail may not be so obvious. (And as I often lovingly write, he cleverly passes the paralleling of batteries to others, though again, BatteryFAQ does contain all the raw facts
Finally, thanks for your last comment.
Though not quite the conclusive thread I was hoping for (I think you were lucky else fall short of the original design conditions - hence the importance of realistic normal
operating conditions versus worst-case operating specs), I have noted your success as a future reference.
Besides, maybe those standby
Shurikens are capable of much more - just as my 12 year old Yuasa 38AH UPS battery has survived years of cranking and auto use which - IMO - it shouldn't have. In fact based on a few experiences, my guess is that a Yuasa UXH100-12 or UXH110-12 (100AH or 110AH, 12V) is not only cheaper than the smaller ~70AH Optima equivalents, but will far outlast the Optimas. As to physical robustness, several months ago I dropped my current UXH38-12 about 1m (1 yard) onto concrete, hitting corner first - not edgewise of flatly. Even I was impressed - my first instinct was to run!! And I like dirt roads and speed up to "smooth out" holes, corrugations, and rebel against speed humps, so vibration & shock - at least for the UXH38 - seems not to be a problem.
Anyhow, congrats and all the best.
Let me know if the Shurikens fail "prematurely".
And beware those grasshoppers, or occasional crickets or cicadas, or opera baritones and ringing that also get reported. (LOL - but as my serious tip.)
Oh well, yet another typical short reply...