Search found 18 matches

by socrace
Jan 18 2020 11:56pm
Forum: E-Bike General Discussion
Topic: Stupid Question: Can I solder 18650 cells?
Replies: 58
Views: 5501

Re: Stupid Question: Can I solder 18650 cells?

I found you really need a good soldering gun like the Weller D550, which is 260 watts, about $35.
I built this a couple months ago, 65 recycled LG batteries + holders cost just under $100.
wellerd550.gif
wellerd550.gif (31.46 KiB) Viewed 323 times
batt.jpg
batt.jpg (188.67 KiB) Viewed 323 times
by socrace
Jan 16 2020 6:38pm
Forum: E-Bike Technical
Topic: Wiring Harness or Controller upgrade
Replies: 5
Views: 380

Re: Wiring Harness or Controller upgrade

Bomba,
Contact Radcycles and ask them what they suggest, maybe they'll loan you a harness to test.
by socrace
Jan 02 2020 3:45pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Battery for Ebikling 1200w rear hub
Replies: 2
Views: 338

Re: Battery for Ebikling 1200w rear hub

I have an ebikeling hub kit (1.5kw), mostly ridden at 12mph limit with some pedaling, and find 65 cells (about 650wh) good for accelerating through intersections, going up easy hills, and several hours range (a little longer than I want to sit on a bike seat). Is this what you mean by midrange? You ...
by socrace
Dec 31 2019 10:13pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

I agree with Fechter, as long as the signal line is active low, the ebrake switch can handle the taillight load, and the controller is using 5v not 3.3v logic levels. The 1N4007 will likely have too much forward voltage drop for 3.3v. But looks like OP has access to spice, if so you can model the eb...
by socrace
Dec 30 2019 5:13pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

ebike brake actlow.png This circuit will allow the taillight to be switched without exposing the ebrake switches or controller sense line to whatever voltage is powering the taillight. It will work with ebrake switches that are wired in parallel as shown (active low). The simpler circuit shown earl...
by socrace
Dec 29 2019 9:11pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

Yeah, your method of applying full taillight voltage on the ebrake signal line should be safe, especially at 12-14v max. 12v on the signal input will drop about 7v across the isolation and pullup resistors in parallel to 5v supply, maybe 2 milliamp total, not a problem. But with 52v on the signal in...
by socrace
Dec 29 2019 6:37pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

Hi Tommycat. Yes it's a very simple circuit, although it does work. When the ebrake switch is open, 5v (through a 5k resistor inside the controller) is provided to gate of the mosfet, charging its capacitance, turning it on, and lighting up the brake light. When the ebrake switch is closed, capacita...
by socrace
Dec 29 2019 11:02am
Forum: E-Bike Technical
Topic: Where would you place a 72v 25ah battery on this frame?
Replies: 22
Views: 1181

Re: Where would you place a 72v 25ah battery on this frame?

I had a similar problem with my build, and calculated that one standard astm sized brick is about same volume and weight as 45 18650's. One brick =205x90x50mm, 1590g. One 18650 = 65X18X18mm, 45g. So 200 batteries is about same weight and volume as 5 bricks. Not exact but close enough for trying out ...
by socrace
Dec 27 2019 2:59pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

Well, I went down the rabbit hole of trying to find how "standard" Chinese controllers are configured for ebrakes. Answer from most sellers is: "don't know don't care as long as you buy from me". So anyway, am now pretty sure amberwolf is right; most ebrake switches are normally open (N.O.), and are...
by socrace
Dec 26 2019 4:18pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

Yes, another inverting stage like you described would be needed, if the signal line goes to zero to trigger the ebrake!
by socrace
Dec 26 2019 2:58pm
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

The controller ebrake input has at least 2 wires; ground and a signal line with 5v on it supplied inside the controller by a pullup resister. Some newer controllers have 3 wires, the same 2 wires plus a constant 5v supply line for a hall sensor (for hydraulic brakes). In either case, the front and r...
by socrace
Dec 24 2019 11:28am
Forum: E-Bike Technical
Topic: brake light wiring
Replies: 20
Views: 892

Re: brake light wiring

Not really sure how yours would work, is the circled component a relay? Here's what i'm using:
ebike brake.png
ebike brake.png (2.25 KiB) Viewed 811 times
The mosfet can be about any logic-level nchannel within voltage and power rating, such as this.
by socrace
Dec 22 2019 10:09am
Forum: E-Bike Technical
Topic: 20 li-ion battery doesn't reach full charge.
Replies: 16
Views: 871

Re: 20 li-ion battery doesn't reach full charge.

https://batteryuniversity.com/learn/art ... ion_to_die
Although, I charge to mine to 4.2, since I don't have the same problems oems face..
by socrace
Dec 21 2019 11:49pm
Forum: E-Bike Technical
Topic: 20 li-ion battery doesn't reach full charge.
Replies: 16
Views: 871

Re: 20 li-ion battery doesn't reach full charge.

Optimal charge for a liion battery is sometimes stated as 3.92v for longest cycle life, giving 78.4v for 20s. This is the max charge voltage used by Nissan Leaf and Chevy volt for some of their batteries. Your charger could be using constant current mode until 3.92v is reached, then taper to zero at...
by socrace
Dec 20 2019 11:34am
Forum: E-Bike Technical
Topic: 42V/4A Charger Compatibility Question
Replies: 2
Views: 319

Re: 42V/4A Charger Compatibility Question

https://www.ebikes.ca/learn/connectors.html#rosenberger
So, charger voltage will probably not turn on unless can bus negotiation with battery succeeds.
by socrace
Dec 17 2019 6:15pm
Forum: E-Bike Technical
Topic: Can a Faulted BMS be woke up with a capacitor?
Replies: 8
Views: 791

Re: Can a Faulted BMS be woke up with a capacitor?

The problem could be due to exceeding 85 amps (as you suspect), but could also be due to a weak cell (parallel group) that is sagging under load below the protect voltage. If that's what's happening, the charger or regen may then be recharging the weak cell enough to turn off the protection circuit.
by socrace
Dec 15 2019 12:24pm
Forum: E-Bike Technical
Topic: Faraday Auxiliary Battery Pack do it yourself
Replies: 5
Views: 649

Re: Faraday Auxiliary Battery Pack do it yourself

Your bike probably uses a 36v 250w Bafang geared hub motor, so battery is probably 10s, although they describe it as 43v so verify it. The charger is probably 2 amp. If I was building this, would probably try to use an off-the-shelf low wattage 36v battery pack with a 20 amp dc circuit breaker in se...
by socrace
Nov 30 2019 2:58pm
Forum: E-Bike Technical
Topic: Why doesn't a li-ion battery take load?
Replies: 24
Views: 1947

Re: Why doesn't a li-ion battery take load?

Measure each cell voltage individually while motor is running to find possible bad cell (diff voltage across the bad one).