It’s a less common word, but yeah I think most folks around here know it. Not as many folks as a borrowed word like cojones though.
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Haha. Seems to have Indo-European roots, which is why we’re all familiar with it. I’m sure English got it from Latin, same with French.
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What’s the proper Inner Tube size for bergmeister tires? I see 145/45 on the sidewall but that’s not getting me anything on the web. Also, a cheap US place to buy from. I just popped 3 of mine and I use it to commute.
Hi
Regarding battery build
If we want to build high AMP output lets say 12s6p we need to take under considerations safety of the pack especially anything above 4p ( cell Thermal Runaway )
There is no issue with 2p in terms of TR.
Why not to build 3 times 12s2p and connected them together
Dont we achieve same output without TR risk ( no need to think about CLF -cell level fusing )
Just open question thnx
When building any pack of any size and any amp output we need to take thermals into account
What is this statement based off of?
Because that would require 3 BMS’s, as well as a ton of extra wiring, insulation, and space in the enclosure.
For most people’s use, a properly spec’ed battery should not be experiencing thermal build up or thermal runaway.
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Are you claiming that the risk of thermal runaway increases with the more cells you have in parallel? Even though the current per cell decreases more and more as you have more and more cells in parallel?
I’m ignoring for now how it’s almost impossible to bring a cell into thermal runaway just by running it very hard. A short circuit, internal or external, is typically needed.
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what i meant is that in case 1 cell failure there will be only one other from 2P to dump A on faulty one
which mean much less risk of catching fire compare to 6P and having 5 cells dumping A
wouldn’t be better to spend few more £ or $ for extra BMS and wiring rather than putting at high risk few k investment into board or ebike
in terms extra insulation why not use liquid silicon base insulator which is same time very good heat conductive material instead of fishpaper ( batteries would have to be mounted — 3d printed spacers )
and i know very often space we have is a key factor
and again just humble open questions – trying to learn
thank you
there is a lot written on battery build sections about TR with higher P sections and considering CLF solution
there is also $ benefit in modular design
of course initial cost of 3 times 12s2p will be higher compare to 12s6p
but if smth goes wrong you will have to investigate single module instead of whole pack
and you could easily keep spare 12s2p ( which would be cheaper than whole 12s6p )to cut to almost zero downtime
therefore in principal apart from extra bms and wires is there any other drawback on having 3 modules of 12s2p instead one 12s6p
Much Obliged any feedback in this subject
thank you
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sorry one more questions in terms of extra BMS vs limited space
In high output pack we would use BMS for charging only
So there is no need to have them installed in enclosure
we could design custom charger including BMS system
Hi I bought 2 vesc from @torqueboards, one works fine but this happens to one of them when I hit the throttle.
Any ideas what the problem could be? I contacted TB and I’m now waiting for a response.
Maybe consider just using passive balance boards instead of a whole BMS
There is no video. You can drag .mp4 files into the composer.
Sorry here is a google photo link. I’m using a phone. https://photos.app.goo.gl/wty3eNwAJDaZCwBC8
Basically a red light blinks 3 times when I hit the throttle.
noted thank you
will check this
Type “faults” in the terminal. What does it say?
Did you do motor detection?
Would it be possible for single BMS to balance charge 3 separate P sections ??
lest say we would use same BMS capacity as we would have 12s6p
thank you
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Yes, but you shouldn’t. If the parallel groups between packs are not at the same voltage then they will rapidly balance via the tiny balance leads and that could melt the wires depending on how out of balance they are, and it’s not great for the cells. If you use the battery in that format then any discrepancies between corresponding parallel groups will certainly melt the wires (if a group has less resistance then it will funnel current through the balance leads from one pack to the other)
Recommendation is have 3 BMSs, or have more substantial series connections between the packs
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