Oh fuck that’s weak…how big was the pack?
Any thoughts from the group appreciated. Semi flex 12S4P pack dropping from 48V to 40V (confirmed with direct voltage measurement). Suspecting a loose series connection since the cells are all balanced and at proper voltage still.
What’s strange is, if a series connection issue occurred, wouldn’t that make one of the terminals of the XT90 connector no longer connected to the battery? Or do voltage drops like that occur when the connection is poor.
Was intermittent, now stuck at that voltage.
We banged and twisted everything, couldn’t replicate the problem on the bench. It has occurred again now while riding. Bumps can fix or cause it inconsistently.
Appreciate it
Did you check on your parallel connections? Sometimes if one pops loose, it can cause really weird voltage drops
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My Dog cells were at a few different voltages as well. I said fuck it and charged all 140 to full. Took a few days as I only had 2x 4 bay chargere, but much less hassle to throw them on and come back when they are full than to sit around watching grass grow. My ¢2 anyway 
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Good to know I’ll give them a look while it’s open
True, but I want to build the pack tomorrow so we can finish a MTB the day after and ride on the weekend
Between exams and projects it’s not much time to work on the board so I gotta use all the time I can
Rn I’m watching Avatar and all the cells are chilling next to me…due to a fuck up on a single sell I gotta bring these suckers all up to 3.90V now
About to place an order for some 30Qs and nickel strips from liionwholesale.
Seems like they only have 10mm wide nickel, should i get wider ones?
Also probably gonna get a charger to charge each cell individually.
Would this work?
Depends how many amps you planning to pull. Can always double them up too
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Yup, and the conductor current thread just got updated so check that against what you’re building.
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What do you think guys about that design?
- honeycomb holders
- nickel and copper braid
- fish paper inside the pack between P groups
- fish paper outside the pack
- non-flammable mat on top and bottom of the pack
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Did you die cut your paper? More info please 
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I’d guess laser cut, I think I see the telltale slightly browned edges.
Makes me want a laser cutter even more now.
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Yes laser cut! It’s 0,25mm and 0,4mm paper
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looks sick as f***
Good Job man!
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Why the flame resistant mat? Seems like that would just trap heat in, that laser cut paper tho 
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That’s so wild, what’s the specs and what’s it being used for?
Pretty crazy amps as usual for you
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Lol, its definitely not mine. This was pulled from a Trampa. The battery has dropped to 2.3V per group and needs to be brought back up to acceptable levels.
It also needs to be completely fucking rebuilt 
Do NOT get Bajaboards to build you a custom battery. This shit is fucking disgraceful.
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