Ruston Gas turbine cranking battery
Ruston Gas turbine cranking battery
(OP)
Normally, the cranking batteries in automobiles are VRLA batteries that run about 3years on average and need no water top-up.
How about using Sealed Ni-Cd battery for cranking? The requirement is for Gas turbine cranking with battery size of some thing like 230Ah (Ni-Cd) for two crank capability. The location is in the desert with temperatures crossing 50degC at times.
Appreciate if you can share your opinions / experiences!
Thanks.
How about using Sealed Ni-Cd battery for cranking? The requirement is for Gas turbine cranking with battery size of some thing like 230Ah (Ni-Cd) for two crank capability. The location is in the desert with temperatures crossing 50degC at times.
Appreciate if you can share your opinions / experiences!
Thanks.





RE: Ruston Gas turbine cranking battery
Can't comment about turbines.
RE: Ruston Gas turbine cranking battery
sealed cylidrical ni-cads or low maintenance ni-cads has long life and more efficient. but the peak current requirement decides the selection of batteries. Ni-cads are capable of delivering up to 10C rate (10 times of their Ah rating) for about 20 seconds and 25C rate for about 2 seconds. the is no much change in the efficiency of the battery at 50 degree C.
--QA
RE: Ruston Gas turbine cranking battery
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Sometimes I only open my mouth to swap feet...
RE: Ruston Gas turbine cranking battery
( You need 11 x 1.2V Ni-Cd cells to make a practical '12V' car battery. The car system will overcharge ten cells, or die trying. )
( It's a good idea to cover the intercell links of such a battery. The short circuit current of NiCd cells that size is sufficient to melt a dropped wrench. )
Mike Halloran
Pembroke Pines, FL, USA
RE: Ruston Gas turbine cranking battery
ScottyUK,
My assessment also is that Ni-Cd are 3times more expensive. But, you know any organisation which specifies Ni-Cd for cranking applications!
RE: Ruston Gas turbine cranking battery
The only Ni-Cad cranking batteries I'm aware of are on a couple of fire pumps, and these somewhere around the 60AH size. I don't know why these were originally spec'd as Ni-Cad, but much of this plant was designed by US engineers and we've kinda surmised that the Ni-Cad cranking battery must be from a US standard. If anyone can shed any light I would be interested.
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Sometimes I only open my mouth to swap feet...
RE: Ruston Gas turbine cranking battery
it is mostly used aircrafts, metro tarins etc, due to the requirement of high starting current. presently, SAFT (France) is manufacturing Ni-cad batteries for every application which includes electric cars.
--QA
RE: Ruston Gas turbine cranking battery
The main argument in favour of NiCd was that after it had been cold-soaked to something like minus 40 (F or C), you stood a better chance of getting a cranking current out of one than from a Lead Acid battery - and since all our current front-line aircraft were specified in the days when we thought the next war was going to be fought somewhere cold,that's what they got.
A.