If everything you’ve said is true, then I would not use that BMS.
Check and make sure your multimeter battery is not dead, sometimes that causes bad readings.
Anyone here have any experience with the Sony VTC6? Spec wise they seem very similar to the 30q.
EV West has these cells for sale at $3 ea, which seems like a pretty good deal, if they are a quality cell. Any feedback or personal experience would be appreciated.
Thanks!
VTC6 are good. $3 is a good price. There’s some question about its cycle life and capacity at high loads vs the competition, but it seems relatively minor. It’s probably still better than 30Q overall.
Are you talking about this?
https://www.evwest.com/catalog/product_info.php?products_id=484&osCsid=3c4nm854g9cnjj82kuqs49lg35
$3.15/cell, 200qty, looks unwrapped.
Hi everybody,
I am getting a trampa complete (with a monsterbox) and a 12s7p battery built locally.
I need to figure out something for the charge port and I would ideally like to be able to take the battery out without having to remove any soldered wires so that I could swap out for lighter batteries to make it a jump board.
I was thinking what would be ideal would be something along the lines of a XT60 port that has a male plug on each side so I can just get the board, mount the port and then plug in the battery.
Does this sound like a workable solution? If so, would any of you have a link to buy such a port (or something similar)?
You could buy a 4usd xt90 parallel conector and use the wires and connectors of the monsterbox for charging when needed…Just unplug and change for lighter lipo batts…
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I think the monster box has wiring for 2x6s, so maybe get your battery made as 2x6s 7p instead of 12s7p and than just use the wiring which comes with the box.
You can also easy charge through the xt90 and take the packs out.
I don’t use the monster box, but similar princip.
Just 2x6s made a xt90 serial plug and I charge the packs with an external bms.
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Ah, someone with the elusive 2x6s pack my battery builder talked about but confused the hell out of me and was beyond my google-fu to research properly (I now realise I was off on how the two packs were split).
The builder mentioned that a previous customer had done this and (I may have misheard) that this (2x6s) could be charged without a BMS as long as you have a balance charger. Does this sound right?
And would it be possible to charge like they do with the monsterbox and zippys in this video?
Also, what are your thoughts on just getting a Graupner Ultramat Charger? Charge time for now is not a major concern, better charging systems can just be purchased down the road when I have more hands on experience with it all (it also looks like it could fit in a backpack nicely).
If I get a yes to the above three questions I think I am ready to pull the trigger so your help is much appreciated.
[Side question: If you happen to have a photo of your batteries, BMS and charger all connected so I could see the layout that would be awesome]
If you have 2x6s than yes you could charge each pack individually with a 6s hobby charger but you should match always the voltage of the packs.
If you get 2x6s packs than yes you could charge it just like the lipos trampa does.
I assume your battery builder will wire the balance wires and adapters for each pack like it would be on a 6s lipo pack and yes that would than also work with the charger trampa sell or recommend on there website.
That’s how my packs are wired up for charging with a smart bms (smart bms gives you the opportunity to check each p group voltage via app and adjust cut off and other parameters)
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Legend, thanks mate you just solved all my problems.
I do like the thought of the smart BMS as the battery builder mentioned he can supply them and they work quite well. I think I might have a mull over going the Graupner charger vs. BMS + brick routes over the next day or two and then get in touch with Trampa.
Cheers
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The smart bms is cheaper and you can get different brick charger but balancing takes longer than with the graupner or ultra charger.
Both ways will work for it, so don’t overthink it 
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Battery is done. Finally
Built an improved charging port. @deucesdown
Sheet of 1mm teflon for insulation.
Battery barely fits, but that is perfect for me
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Yes, those are the ones. I’d have to wrap them myself but that seems straight forward, though time consuming. Thanks for the feedback.
This might be a silly question, but is it possible to pull the entire current from the battery straight throught the nickel strips, or do I need some kind of hub going through to be able to carry all the currrent? I’ll be using 8x0.15mm nickel strips and will probably double up every connection.
Also second question: why not use copper strips with higher conductivity inseted of the nickel plates?
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People have found it much more convenient to solder strand wires rated at higher currents rather than having to stack the necessary amount of nickel plate. The nickel plate method is more time consuming and opens up to more possibility of failure in the way of broken welds. It is also my understanding that the difficulty of welding copper strips outweighs the benefits. But this is just what I’ve gathered, open to more insight.
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On my pack intended to draw 160A, I doubled up the nickel and soldered 8AWG solid copper across all the P groups, and used 2x 10AWG silicone wire to connect the P groups with 8AWG silicone for the main leads. Soldering the solid copper across the P groups was probably not the best for the cells, but they seem to be fine since voltage drop is super minimal, capacity is great, and everything is in balance.
To answer my own question, so others can learn.
after few emails with Bestech, I made video for them checking voltages on balance wires. voltages were 3.44V except two groups where they were lower. and Bestech’s answer was if I am using LiFePO4 cells? 
after that, I have replaced faulty bms with exactly same D140 (same Batch like faulty) and everything is okay, no heating. still have to try charging it.
In conclusion, yes, bms was faulty out of the box and I still have to convince Bestech that I have nothing with it.
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Has anybody tried this BMS? Do you think it is possible to bypass the discharge? I ordered the 20a version (maybe a stupid decision) because it’s the cheapest, in hopes of being able bypass it.
Also follow up to my previous question: how many of the 8x0.15mm would i need to handle the full 75a of a 12s5p battery?
I too use the 20A version. There’s no problem with bypassing the discharge. That can be done with any BMS.
Can you send me the bypassed diagram?
There’s a zillion of bypassed diagrams on the forum. Nothing special about this one. Just use the search button. You connect the VESC(s) directly to the battery as if you didn’t have any BMS. You only connect your charger and the battery to the BMS. That’s it.
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