What type of charger is used for the lead acid battery?
Has anyone successfully made a power pack for thier flash?
Jim Teo
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Date: Sun, 29 Oct 2000 03:30:12 EST
From: HI100@xxxxxxx
Subject: Re: [OM] Re: lead/acid in M15V
In a message dated 10/27/00 6:43:09 AM Pacific Daylight Time,
wright@xxxxxxxxxxxx writes:
<< I looked around at Digikey, All Electronics and a couple of other places
and
didn't find anything smaller than about a "D" size. I don't know which size
the M15V takes, so this may be a waste of time. I also dont' really know
which type is best for this application. I did find out that those 6V and
12V
lead/acid packs have a bunch of small sealed cells inside the plastic case.
There must be some reason that Quantum uses them, besides cost
considerations, since Quantum battery packs have a good reputation.
>>
The Quantum packs have a variety of cells in them and charger designs
depending on which model and which vintage you are talking about.
For example the Bantams have Japanese made "prismatic" (flat plate) sealed
lead acid cell batterys.
The Quantum battery 1 often has Hawker (used to be Gates/"Cyclon") D cells.
The Quantum battery 2 sometimes have German Sonnenschein prismatic or
Hawker/Gates cells. (Overall dimension compatible)
Few vendors make 8V batteries (as used in Quantum 2) with the same physical
size as the Gates/Sonnenschein. The company I work for ships many thousands
of these 8V batteries per month in our products. Lead acid Battery vendors
seem to go through periods of not being able to control their manufacturing
process very well.
>>There must be some reason that Quantum uses them <<
Lead acid batteries have much lower self discharge rates are about half the
cost of NiCd's and are easier to charge. The voltage can be used as a charge
indicator as is the case in Quantum packs. The energy density is a bit
lower
but they are easier to recycle not quite as toxic(!) and are "very high
rate"
cells. Example: the Hawker D cells can produce short circuit currents of
around 180Amps. this is a good characteristic for flash use and ensures
consistent number of flashes and short recycle times. The only truly small
sealed lead acid cells I have ever seen (as might fit in a MD pack) are for
consumer walkmans etc and have very limited cyle life. The smallest
cylindrical cells I have seen are made by a company out of Colorado (a
Hawker/Gates spin off) they make C cells. These are such high rate cells you
can start your car with a 12V set, with short circuit currents approaching
1000A.
Regards,
Tim Hughes
>>Hi100@xxxxxxx<<
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