4 ms·

They are even matching the internal resistance of the cells, I can't think of much more a professional manufacturer would be doing. As long as they are getting

They are even matching the internal resistance of the cells, I can't think of much more a professional manufacturer would be doing. As long as they are getting their cells from reputable sources (big if) I don't see anything wrong with a boutique battery industry for niche applications.

morphle 2y ago
A professional manufacturer would not put any cell in series but instead would have a charger/discharger with voltage per cell, with current and temperature sensors as feedback loops. The danger of cells in series differs with the cell chemistries. Using a BMS is another indication they are not professional or even had an engineer design them. Sadly I know of only a very few small professional battery pack manufacturers, certainly none of the EV or bike makers.
- ClumsyPilot 2y ago
  > Using a BMS is another indication they are not professional or even had an engineer design them. What is the proper alternative? Do any ebike packs conform to the standard you expect?
- sbierwagen 2y ago
  By "series" do you mean "parallel"? Note that Tesla famously used a 6-series/74-parallel configuration in the Model S's battery pack: https://circuitdigest.com/article/tesla-model-s-battery-system-an-engineers-perspective https://circuitdigest.com/article/tesla-model-s-battery-syst... Each pack only had a single BMS connection for every clump of 74 cells! Presumably they only got away with doing this by doing extensive binning/characterization of the cells before building them into packs.
- _fizz_buzz_ 2y ago
  > A professional manufacturer would not put any cell in series but instead would have a charger/discharger with voltage per cell My Bosch e-bike has 4 cells in parallel and put 10 of those in series. This so called 10S4P is a very typical setup for e-bikes. Each individual cell does definitely not have their own current/temp sensor. The BMS will check voltage for each of the 4 cell blocks.
wolverine876 2y ago
> I can't think of much more a professional manufacturer would be doing Safety equipment, in a safe environment, not exposing others to fire risk?

morphle 2y ago

A professional manufacturer would not put any cell in series but instead would have a charger/discharger with voltage per cell, with current and temperature sensors as feedback loops. The danger of cells in series differs with the cell chemistries. Using a BMS is another indication they are not professional or even had an engineer design them. Sadly I know of only a very few small professional battery pack manufacturers, certainly none of the EV or bike makers.

ClumsyPilot 2y ago
> Using a BMS is another indication they are not professional or even had an engineer design them. What is the proper alternative? Do any ebike packs conform to the standard you expect?
sbierwagen 2y ago
By "series" do you mean "parallel"? Note that Tesla famously used a 6-series/74-parallel configuration in the Model S's battery pack: https://circuitdigest.com/article/tesla-model-s-battery-system-an-engineers-perspective https://circuitdigest.com/article/tesla-model-s-battery-syst... Each pack only had a single BMS connection for every clump of 74 cells! Presumably they only got away with doing this by doing extensive binning/characterization of the cells before building them into packs.
_fizz_buzz_ 2y ago
> A professional manufacturer would not put any cell in series but instead would have a charger/discharger with voltage per cell My Bosch e-bike has 4 cells in parallel and put 10 of those in series. This so called 10S4P is a very typical setup for e-bikes. Each individual cell does definitely not have their own current/temp sensor. The BMS will check voltage for each of the 4 cell blocks.

wolverine876 2y ago

> I can't think of much more a professional manufacturer would be doing Safety equipment, in a safe environment, not exposing others to fire risk?