continuing on from where i left off ...
john61ct wrote: ↑Sep 11 2021 11:36pm
Whether the parallel or serial connections are joined "first",
whether the buss bars or power cables are on top or at the bottom
whether the pack is triangular or rectangular
all these are details pretty much unrelated to the electrical performance
Never implied any thing to the contrary? This is just another example of an unnessary and unwelcome intrusion to possibly derail this thread, get it locked or thrown in the ES trash bin. So who's the real troller ?
One purpose of this thread like the previous thread that was locked is to discuss the best effective efficiency by having the same number of series connections as parallel connections in that each cell serves a dual purpose to provide both voltage power and amperage capacity.
Previously one ES triangular design thread was such that the builder of a 12S4P believed it was sufficient that the twelve p-groups be joined only using two series connections between each p-group of 4 cells. Another ES thread of a 14S5P configuration wasn't able to interconnect all of the fourteen p-groups together using five series connections. Instead because of the triangular configurations decided three series connections was sufficient between seven of the fourteen p-groups.
The question arises: "Is it always possible to design an ebike triangular configuration so that there are as many series connections as parallel connections?" Before answering that question and proceeding with the intent of the title of this thread a review is needed due to the intrusion of an ES member with suspect motive(s).
A quick review considering the unwelcome intrusion misrepresenting the intent of this thread. The intent being to point out that a Master Tri-Pack Builder will attempt to design a triangular pack configuration with as many series connectons as parallel connections to achieve the best "effective efficiency" possible. In other words each cell in an ebike triangular (as well as rectangular, square or circular) configuration ideally will have as many series connections as parallel connections if at all possible.
It becomes apparent that a Master Builder of an ebike Tri-Pack like
thundercamel will design a triangular configuration such that there are as many series connections as parallel connections. Each cell providing both voltage power and amperage capacity as efficiently as effectively possible.
Because of an unwanted and unnecessary interruption will post again the excellent photos of Master Builder
thundercamel and continue with the intent of this Bus Bar / Bus Plate Tri-Pack thread ...
The first thing to contemplate is the fixture that must be built to hold all the cells firmly in place whether spot-welding Bus Bars or spot-welding Bus Plates. Also the kind of spot-welding equipment that allows for flexible movement by the builder and his spot-welding equipment. It helps if the builder is ambidextrous.
Also notice that there is a firm foam-like material separating each cell from coming in contact with another cell. This is very important, but only enough cell spacing with the right material to achieve the limited size objective of available housing and vibration protection.
We can also visualize the same number of Bus Bar parallel connections as the same number of series connections.
spinningmagents posted on another thread that he favored parallel connections being spot-welded first and i see the logic in that as well as the logic in spot-welding the series connections first depending on such factors as the thickness of the Bus Bars, spot-welding equipment, builder expertise, building the p-groups first before spot-welding them together with the series bus bar connections, etc. Bus Plates as we know offer an advantage when it comes to spot-welding the same number of series connections as parallel connections. A little tricky, but certainly manageable.
This excellent photo is where it also becomes evident a possible advantage in using six Bus Plates instead of Bus Bars.
Again an excellent photo from a Master Builder showing the other side where one can easily visualize the shape and number of seven Bus Plates needed if
thundercamel were to opt for using Bus Plates instead of Bus Bars. We can also see the location of the final 6-cell positive connection as well as the 6-cell negative connection on same side in the above photo.
Another excellent photo by the Master Builder in where one can again easily visualize the shape and location of seven Bus Plates should a Master Builder decide to forego Bus Bars in favor of Bus Plates in the above photo.
And finally another excellent closeup photo showing more detail and the use of solder for the positive connection and the negative connection on the same side. So much can be learned from a Master Builder like
thundercamel from studying his excellent photographs of his triangular Master Build fabrication. :thumb: