Re: (ET) Battery Question

["Christopher Meier" <mr23 mn rr com>]

I was under the impression that dragster are not cranked via a
starter that is run from the 12v battery; they are spun up by a
hand held unit that is independently powered.  Please enlighten
us as to the starting method used on the dragster in question.

If I am correct, then the maximum current rate handled by the
charge controller would be the peak draw of the ignition, thus
my original statements/questions.  I imagine this charge controller
would be continuously connected for the whole event, and that
batteries are recharged/topped off prior to the start of the day.

Another point, is if lighter weight batteries are use, the dragster
traction hookup can be adjusted by shifting the standard added
weight around, it would be much more difficult to shift batteries
around to adjust weight loading.  Thus a swappable batteries
with a high enough capacity charger may be the best option.
I'd do a little research on the smallest 8 or 16 volt batteries;
those special purpose 'racing' batteries have special purpose
chargers, and I suspect the 12v and 16v taps on it are not to
equal sized (Ah capacity) blocks, since they would be discharged
unevenly anyway when the 12v is used for starting.

----- Original Message -----
From: "Travis Creswell" <ozsolar ipa net>
To: "Christopher Meier" <mr23 mn rr com>; "Pestka, Dennis J"
<Dennis Pestka TycoHealthcare com>; <elec-trak cosmos phy tufts edu>
Sent: Wednesday, July 17, 2002 8:32 AM
Subject: Re: (ET) Battery Question


> Although it's a good idea, Solar Charge controllers aren't designed to
> regulate the voltage in-between batteries (or banks) of different
voltages.
> A battery can deliver far more amps than a solar charge controller can
> safely "control".  A starting battery is capable of over 2000 amps, a big
> solar charge controller is 40 amps and it costs several hundred dollars.
I'm
> afraid that using a Solar Charge Controller to regulate a battery used as
> charging source for another battery could have disastrous results.
>
> The flooded Trojan batteries are excellent deep cycle batteries for the
> money but they are not what you want to be using.  I assume you are
talking
> about their deep cycle batteries (T-105's and similar models).  They are
not
> designed for starting thus probably will be damaged by the high amp draw
and
> have a very short life if asked to do so repeatedly.  The Trojans also
won't
> hold up to lots of G's either.  The reason they are such good deep cycle
> batteries is because of the high lead content of the plates which also
makes
> them pretty soft and more easily damaged than starting batteries.
>
> The most obvious and easiest solution to me is a higher capacity battery
> charger.  If that is not the route you want to go my next suggestion 
> would
> be two "4D" or "4DLT" class batteries in parallel.  The 4DLT is a little
> smaller than the 4D.  4D's are standard in big trucks and tractors.  They
> are pretty heavy at somewhere around 80 lbs but have about twice the
> capacity of the standard size starting battery so should easily last the
> whole race day, especially if he is able to do some charging in-between
> races.  Another suggestion is to take 2 sets fully charged batteries of
> whatever style then swap out the discharged set for the charged halfway
> through the event.
>
> Just my .02.  My trade is independent power systems thus I am quite
familiar
> with batteries.
>
> Travis Creswell
> E-15, charged by solar
>
>
>
> >Subject: Re: (ET) Battery Question
> >Date: Tue, Jul 16, 2002, 10:10 PM
> >
>
> >
> >Then choose batteries etc to maintain the voltage, with enough
> >capacity.  For example, a solar charge controller powered by
> >2 8-volt deep cycles, charging a small 12v battery at say 14.2v.
> >Ignition runs off the 12v (nominal), 'always' charging at 14.2v.
> >Choose the solar controller power rating to be at least 50% over
> >the peak current draw of the ignition.  A small gel cell could
> >be the12v battery, located very close to the ignition system
> >(for least voltage drop), and the larger 8v batteries can be
> >conveniently placed.
>
> >----- Original Message -----
> >From: "Pestka, Dennis J" <Dennis Pestka TycoHealthcare com>
> >To: "'Elec-Trak Email Discussion List'" <elec-trak cosmos phy tufts edu>
> >Sent: Tuesday, July 16, 2002 3:10 PM
> >Subject: (ET) Battery Question
> >
> >
> >> This isn't really a tractor question, but here goes.
> >>
> >> A fellow I work with races super stock dragsters on the weekends.
> >> He presently runs a no alternator system with (2) 12 volt Optima Blue
top
> >> batteries in parallel.
> >> When he races a lot and gets all the way to the finals, he notices his
> >> batteries getting pretty weak and may not be getting the high voltage
> >needed
> >> for optimal spark.
> >> He charges in between races, but has very little time.
> >> He would like to upgrade and is considering several options.
> >>
> >> Staying at 12 volt with (2) 12 volt Optima yellow tops in parallel.
> >>
> >> Staying at 12 volt with (2) Trojan 6 volts or (1) 12 volt.
> >>
> >> Using a higher voltage combinations, say 2 Trojans, (1) 6 volt, (1) 8
volt
> >> in series for 14 volts.
> >> Even higher voltage with (2) Trojan 8 volts in series for 16 volts.
> >>
> >> He is now adding 80 pounds of ballast to get to the minimum racing
weight,
> >> so the extra weight of the Trojans should not be a problem.
> >>
> >>
> >> I know they would have a higher amp hour rating and last longer, but
would
> >> the Trojans be able to deliver the amperage needed during the race
versus
> >> the Optimas ?
> >>
> >> Would the G forces be a problem with the Trojan floodeds versus the
> >Optimas
> >> ?
> >>
> >> Any opinions ?
> >>
> >>
> >> Thanks;
> >> Dennis
> >