c70r said:
Have read the whole thread and tried searching elsewhere but how exactly would you go about deciding which size of fuse wire to use.
Do you know WHY some DIYers use a fusable connection between the parallel cells while other DIYers just as knowledgeable / experienced choose not to use either wire, resistor or glass fuse links between parallel cells?
Is it because some ebikers just love to tinker and any excuse to solder, solder, solder OR because they are using salvaged cells OR is it because the packs they build are performance packs pushed to the limit OR is it because they don't want to invest in an expensive first-class BMS (+$100) OR a combination of all four. If so then WHY do other very knowledgeable DIYers decide not to use fuses? Is it because they see the importance of investing in a first-class BMS OR is it because they use only new expensive reliable cells OR is it because they balance charge keeping a close eye on pack cell condition OR is it because they are more interested in longevity than "raw performance" OR a combination of all four?
Do you really need a BMS, even morese if you can only afford a cheap Chinese BMS?
Have you determined beyond a shadow of doubt WHY you're going to use fuse wire between your parallel cells?. Is it because you're using salvaged cells that you've determined are good enuf, but still questionable? Or like flippy are you more concerned in "raw performance" (pedal to the metal) than pack longevity? Like Shawn McCarty, docware and myself i question the need for a BMS when longevity is my objective and keeping a close eye (cell checker) on brand new pack cells and balance charging (when needed) instead of relying on a relatively inexpensive BMS to protect my DIY build.
Maybe, what you need to consider is whether or not to incorporate a couple of these to your pack. Only available up to 8S so need two for my 10S5P build ... https://www.amazon.com/ISDT-Battery-Meter%EF%BC%8CLCD-Capacity-Balancer/dp/B07797N9BG/ref=pd_sbs_21_img_0/139-5157333-5670654?_encoding=UTF8&pd_rd_i=B07797N9BG&pd_rd_r=5ca67aa4-5e4c-44d4-80e8-c807a43b4de3&pd_rd_w=kYKsF&pd_rd_wg=4IMYY&pf_rd_p=5cfcfe89-300f-47d2-b1ad-a4e27203a02a&pf_rd_r=T21BSZXTEF4BZEZV0CF5&psc=1&refRID=T21BSZXTEF4BZEZV0CF5 ... also get a cell checker if you don't already have one. Invest in a good reliable cell checker not one of those cheap ones.
With respect to the disinformation by flippy and john they are poor sports. Flippy's comment apparently reflects his dissatisfaction that i indirectly made a reference to Macho Man (an ebiker more interested in "raw performance" from a pack more so than getting the most longevity lifetime performance from a pack. What's your application ... raw performance or longevity performance? And then how does your application (e.g. raw performance, salvaged cells, personal preference) justify the need for fused connections?
As for john he is coming around to the advantages of a DIY Vruzend pack using one or more V2.1 kits (nickel/copper busbars and compression barrel bolts). Previously both john and flippy considered Vruzend "crap" (flippy may still consider it "crap") ...
john61ct said:
Is it the consensus here, based on experience, that the Vruzend approach really is "crap"?
No, it's not the consensus. Just ask Erik about his 14S8P Vruzend pack ... https://endless-sphere.com/forums/viewtopic.php?f=14&t=102387&start=150 ... scroll down
As far as parallel groups and series strings i used john's preferred usage in my above reply. john's disinformation post is not helpful (neither is flippy's disinformation comment). They may need a warning to STOP. In other words Get-Over-It guys instead of provoking comments that require a lengthy reply to correct the disinformation / misinformation.
When Ron used "string" in reference to a parallel group he was right because in a rectangular pack both series and parallel cells are in a straight line. Since the use of triangular DIY pack builds the term "group" is correct. A good example of a '"group" of parallel cells (i.e. 8P) is this diagram of Erik's 14S8P Vruzend triangular pack ... <img src="https://endless-sphere.com/forums/download/file.php?id=262283" alt="Wallpaper-IngridMika-Contact-Grid-1-1100x1318 - Copy - Copy - Copy.jpg"/>
It's unfortunate that both flippy and john are still smarting and somehow think by discrediting me (and derailing this thread) they elevate their own credibility. Whereas, determining your pack's application and thus the reason(s) for using wire fuse links between parallel cells is most relevant to this thread.