OT: WARNING Landmine on Van Ness, SF (NB 101)...

[Eddy Lee]

On Monday, July 17, 2023 at 1:37:21 PM UTC-7, Bertrand Sindri wrote:

Eddy Lee <eddy7...@gmail.com> wrote:
On Monday, July 17, 2023 at 12:40:18 PM UTC-7, Bertrand Sindri wrote:
Eddy Lee <eddy7...@gmail.com> wrote:
On Monday, July 17, 2023 at 11:14:41 AM UTC-7, Bertrand Sindri wrote:
Eddy Lee <eddy7...@gmail.com> wrote:
Testing my expansion battery using
AC110V->DC168V-(/7)->DC24V-(x2)->DC48V-(x8)->DC192V-(x2)-> DC384V..
What a waste. Assuming an optimistic 97% efficiency for each of your
conversion steps (an *very* optimistic assumption) then your five
conversion steps have wasted 15% of the incoming energy just in
conversion losses.

No. at least 99% overall. No energy loss with jumpers and toggle
switches, one time energy loss in bi-stable relays. There are no
passive components, but burn-out fuses sometime.

How are you obtaining 99% overall with five conversion stages..?

upshifting (in series) and downshifting (in parallel).
Upshifting? Downshifting? Those works would make sense when
discussing an automotive transmission, but they make no sense
electricaly.

Do you mean you connect (connect is the right term here, not shift) the
batteries in serial and or in parallel for the voltage changes?
AC to DC entails rectification -- there will be some loss in the
rectifier.

OK, one stage loss, but inevitable in any converter.

Then, how do you divide 168VDC by seven without any losses?

Shifting DC168V (in serial) to DC24V (in parallel).
Again, wrong word. Do you mean you change from serial connected
batteries to parallel connected batteries?

Yes, I guess I am inventing terms. Upshifting and downshifting voltages.

Then how do you double 24V to 48V without losses, then multiplying
48 by 8 without loss to get 192V? And then how do you double the
192V to get 384V without loss?

Again, standard serial/parallel shifting.
There\'s nothing standard about your using the word \"shift\" in this
context.

I mean standard voltage doubler/halfer circuits.

Furthermore, they are balanced at 12V or 16V level.
What does this statement even mean?

There are internal 3 stages BMS for the 12V module.
What 12V module? In your long chain of conversions your lowest voltage
was 24V. Where do you get \"12V\" from?

24V is 2 of 12V. The 12V modules are usually well balanced. As long as I keep them balanced at 24V, they won\'t get too out of balance. I do check them every few weeks.