How do u make this… I am going to need a reliable on off switch for my battery build
Super easy I got the idea from someone on this forum but I forgot who so thanks to whoever that was. I’ll link what you need.
XSCORPION (CB100) 100 Amp Circuit Breaker with Manual Reset https://www.amazon.com/dp/B00MR1LVVC/ref=cm_sw_r_cp_awd_UoDaxbSR6VWNG
Shuts your main power off so you don’t even need to unplug you battery. I used it on 6s for months and it’s fine. I have a pretty beefy soldering iron so I can solder the 10 gauge wire to the screw posts. You could use the included nuts but I wasn’t sure how those would fair with vibrations
@barajabali it’s @lowguido who has written about using a circuit breaker as an on/off switch. It’s a cool solution the only drawback to it that I’m aware of is the large size of the switch.
Does he use this exact breaker? I got the idea from some long who uses this exact breaker
Sure do. I have been using that breaker on 6S for over a year with no issues. it is rated for 24V so I dont know how well it would work for more than 6S?
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I think that would work well I I just need 10s 
Right now battery supports is having some trouble accepting payment. @chaka had suggested bestech, and he’s the man, so I trust this suggestion. May require a group buy to get though; they are a wholesale group
http://www.bestechpower.com/37v10spcmbmspcbforli-ionli-polymerbatterypack/BMS-D266.html
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Be sure to specify a high overcurrent protection. They can probably take that unit up to 80 or 90 amps.
edit: just remembered you are going 10s3p.
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If anyone is planning to order from batterysupports, they have a shop supowerbattery111 on ebay and shipping prices are much cheaper ordering through ebay (for the same speed as far as I can tell).
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Thanks @chaka
We are having some confusion about selecting a BMS for 10S3P vs 10S4P… what about the BMS or the charger should be adjusted for the number of parallel groups? It’s unclear to me whether the charger or the BMS is responsible for cutting off power once the desired voltage has been reached. What are the considerations for a BMS as you add parallel groups to a battery pack?
You guys are doing a group buy so I wouldn’t make things too complicated. Get the most robust bms you can get your hands on and build a min of 10s4p with 20 amp cells. Use the bms for its low voltage cutoff and balancing functions. The max continuous discharge and peak discharge values just show what the bms is capable of without failing.
Cells rated for 20 amps are not going to magically output 40 amps. They may peak for a second or two but voltage will sag pretty hard throwing the low voltage cutoff. The max current cutoff on a bms is to protect the bms not the pack. So you can see budget and bms dimensions are your only limiting factors.
Charging li-ion cells: Divide the packs watt hours by a factor of 2 and find a charger that matches that number. You don’t want to charge faster than 0.5C
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You guys should do a group buy at green bike: http://www.greenbikekit.com/battery-charger.html Pick your wattage, voltage and connector style and they do the rest. Shipping starts around $45 so you need to buy more than one to see any savings.
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Avoiding an imminent hijack of @longhairedboy’s build thread, I’m bringing the question of nickel strip selection here. The question is simple, which size and thickness of pure nickel to we need in a 3p or 4p configuration with 18650 cells?
@eLDoska shared that:
so for a 3p unit with 3.7 nominal voltage and 20A discharge, which strip is optimal? Starting to think I should just use copper wire throughout.
@chaka @torqueboards @onloop @elkick @sl33py calling you guys in for reinforcements here - any thoughts on the right selection of nickel strips?
@treenutter Thanks for doing this. I feel like those numbers were a little low considering what i’ve seen inside of actual packs. If i come away feeling like i have to triple layer my 8mm strips, i’ll do it, but i’m not convinced i need to yet.
I didn’t buy a spot welder so i could solder 10awg wire down the sides of my packs. I have over 50 feet of wire and a good iron, but that’s not the point.
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If you use black battery spacers 3x1 you need 8mm strips because in most spacers the spaice in the middle is 8mm. With basic motors with 60-70A max, each pack must hold 60-70A - 23A/cell in 3P and 17.5A/cell in 4P. So you need connection between cells that can hold 23A max. And it could be 2 layers of 8mm x 02mm strip (2x15A = 30Amax).
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Check out this stuff… http://www.ebay.com/itm/222080544462?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT .25mm thick…12.7mm wide… OR http://www.ebay.com/itm/221913880756 For about $10 for 10ft.@ 7mmx.1mm thick…
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I’ve also been thinking of getting a switch. Does the switch need to be able all of the amps you push through your battery? I guess im asking if you need a switch capable of 120amps in order not to fry it haha
Just scrolled up and saw the circuit breaker with 100A rating lol thanks
@lunarswift it depends on the battery setup you’ve got. If you’re using a BMS that comes with switching capabilities, then you just need a small switch to toggle it on and off. The BMS I’m using in this build has this feature, so my switch is just a simple rocker switch. If you’re connecting lipos directly to your switch, then yes, you need one that can handle the amps you’d pull. That’s why the 120amp breaker works, same for Vedder’s anit-spark switch with a fuse works.
