In alt.engineering.electrical firstname.lastname@example.org wrote:
|> So you are a dealer of very large cells/batteries.
| No longer. Today the only solar work I do is helping people fix the
| problems caused by poor design.
|> | I can only repeat what I learned getting my accreditation. That was
|> | many years ago and I am sorry that I no longer have the notes to show
|> | you.
|> | The science says that parallel strings do not charge and discharge
|> | equally. Parallel strings should be avoided where ever possible and GC
|> | batteries belong in a golf cart.
|> That's not science. Science would tell you why and how that happens.
|> Further, science would tell you how they behave under various methods
|> of connecting charging and discharging circuits.
| The science is that cells all have different internal resistances.
I guess you don't have an EE degree.
Not that I have one, either. But I respect the knowledge AND understanding
real engineers need to have. The information I seek is what would be
learned in an Electrical Engineering, Power Elective, curriculum (not all
of it, of course ... just the parts I'm interested in right now).
|> You're taking the training you've been giving regarding certain finite
|> methods to install battery systems, and calling it "science". Real
|> science comes from research laboratories and investigative processes
|> that explore all options and find out why things really happen and how
|> control methods may or may not work.
| As you wish, but, all the systems I designed using my training have
| worked to spec.
Are you talking about true design, or just mere deployment configuration?
Bob needs twice the capacity as Carl, so you install a system for Bob
that has a string of cells twice as big as those you installed for Carl,
that's NOT "design". That's "configuration". You select a design (one
single string) and you select a capacity based on available models.
Configuration is when you select from existing known designs. Have you
ever installed a system which was wired different than _any_
ever saw before?
|> | If you want to use them, fine. But in the long run you will say, "That
|> | bastard was right".
|> | The tests were done at Royal Melbourne Institute of Technology in
|> | Melbourne. The test was done on a rig of six parallel strings of six
|> | two volt cells. They tried all the tricks like isolating the strings
|> | with diodes and fancy interconnecting of cells. The results were
|> | always much the same. Unbalanced charging across the array.
|> What kinds of chargers did they use? Did they have separate chargers for
|> each string?
| Shit, that was close to twenty years ago. Battery technology has not
| changed much since.
But you didn't want to answer my question. Don't worry, you are under no
obligation to answer it. And, besides, this is Usenet. Most questions go
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