Search found 37 matches

by electric_nz
Mar 26 2020 2:11pm
Forum: Battery Technology
Topic: 90% Battery Charger
Replies: 10
Views: 301

Re: 90% Battery Charger

Luna 52V charger has 80-90-100% charge setting and 3/4/5 Amp charge. I've used one for years
by electric_nz
Mar 13 2020 1:58am
Forum: E-Bike General Discussion
Topic: Battery Disconnect method.
Replies: 57
Views: 1786

Re: Battery Disconnect method.

There are a few BMS out there with an on off switch; they use the mosfets to switch the battery current on and off, with no need of a large switch.
by electric_nz
Mar 11 2020 12:11pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Powerful e-bike commuter/runaround for hilly area
Replies: 6
Views: 541

Re: Powerful e-bike commuter/runaround for hilly area

for steep hills you definitely want a mid drive so you can use the gears to climb any hill. however it's unlikely even with 2500W you are going to hit 25mph uphill, perhaps 15-20? Overdriving it by that much is also likely to kill the motor- if you're using it for a work commuter then you need relia...
by electric_nz
Mar 10 2020 12:50pm
Forum: E-Bike Technical
Topic: Gorilla Tape on 18650 Battery Pack
Replies: 2
Views: 161

Re: Gorilla Tape on 18650 Battery Pack

It's ok but can lose its stickiness and come loose, and/or get holes worn through on sharp points due to vibration. thick PVC tape in a few layers is better.

It's completely an insulator at the low voltages in a battery pack (unless saturated with water perhaps)
by electric_nz
Mar 02 2020 3:25pm
Forum: Battery Technology
Topic: How do I choose which battery is the best for my application
Replies: 6
Views: 464

Re: How do I choose which battery is the best for my application

sounds like a dream life for any cell, at 15A draw divided by 14p you will only be drawing less than an amp per cell. if you limit the charge and discharge to 90% and 20% you should get good cycle life. suggest reading the thread on Li-ion battery aging, some of the testing suggests 1000 charge cycl...
by electric_nz
Mar 01 2020 2:01am
Forum: E-Bike Non-hub Motor Drives
Topic: new cyclone 3000 w mid-drive kit?
Replies: 3300
Views: 415629

Re: new cyclone 3000 w mid-drive kit?

Edit for clarity: I have the non Bluetooth version and I’m interested in how the default settings compare to the Bluetooth version. Anyone using the black Bluetooth 40A controller as pictured here? Are the stock settings the same as the non Bluetooth version and how does it run out of the box? http:...
by electric_nz
Feb 20 2020 11:59pm
Forum: E-Bike Build Threads / Photos & Video
Topic: Building my first ebike - advice needed ;-)
Replies: 4
Views: 601

Re: Building my first ebike - advice needed ;-)

I have an older giant xtc2 and that thing is solid af even at high speeds. If you’re going bafang may as well go for the bbshd and get the extra power. Pretty much any cell in 5P config will handle the draw. Look at a Luna charger that will allow you to charge at 90% and control the current.chain li...
by electric_nz
Feb 20 2020 11:53pm
Forum: Motor Technology
Topic: MotorModders motor modding thread
Replies: 4
Views: 293

Re: MotorModders motor modding thread

How big do phase wires need to be?? I mean, I’ve seen some pretty thin battery wires that handle 50A just fine without getting warm, but allegedly phase wires need to handle 20% more pulsed and therefore need to be huge. Why would they need to be any bigger than the winding they are feeding in to!!
by electric_nz
Feb 12 2020 2:13pm
Forum: Battery Technology
Topic: Dashcam car 18650 bms battery DIY charge with car battery.
Replies: 11
Views: 559

Re: Dashcam car 18650 bms battery DIY charge with car battery.

Wouldn’t it be easier to just connect to the car battery somehow? What do you need the extra battery for?
by electric_nz
Feb 10 2020 2:28pm
Forum: E-Bike Non-hub Motor Drives
Topic: Bearing upgrades on cyclone 3000? worth it?
Replies: 7
Views: 563

Re: Bearing upgrades on cyclone 3000? worth it?

Note that the motor output shaft reduces to 10mm (with keyway cutout) where the steel output gear attaches.

there is a cyclone 4000W motor available on their site which may be more suited
by electric_nz
Feb 02 2020 3:12pm
Forum: E-Bike Non-hub Motor Drives
Topic: new cyclone 3000 w mid-drive kit?
Replies: 3300
Views: 415629

Re: new cyclone 3000 w mid-drive kit?

Anyone have any idea what MOSFETs the standard controller uses? And the 60A version?
by electric_nz
Jan 31 2020 12:12am
Forum: E-Bike Technical
Topic: Detecting counterfeit 4110 mosfets
Replies: 184
Views: 31668

Re: Detecting counterfeit 4110 mosfets

As a datapoint, just picked up a shipment of these from digikey. Note the laser etched logo and slight notch in the metal tab. Image
by electric_nz
Jan 30 2020 2:39am
Forum: Motor Technology
Topic: Bosch Perfomance Line Throttle Mod
Replies: 10
Views: 1507

Re: Bosch Perfomance Line Throttle Mod

Great idea. I’m guessing the nylon gear and heat generation would limit the power you could pump through it, but it certainly looks way overbuilt for 250W!
by electric_nz
Jan 13 2020 7:24pm
Forum: E-Bike Technical
Topic: Best motor for throttle only usage
Replies: 1
Views: 338

Re: Best motor for throttle only usage

single reduction cyclone 10kW type thing? mid drive direct drive from motor to large rear sprocket, no freewheels, left side drive on the disk brake mounts?
by electric_nz
Jan 13 2020 4:52pm
Forum: E-Bike Technical
Topic: samsung 40t 21700
Replies: 6
Views: 520

Re: samsung 40t 21700

in your 4p what kind of volt sag are you getting? 50amp peaks at what voltage? about 4 or 5V sag at 52 A according to my watt meter. (14S pack going from 56.5V starting voltage to approx 51.5V at peak current) Also note that 20km at say 40km/h is 1/2 hour. estimating you use 25A continuous (1/2 pea...
by electric_nz
Jan 12 2020 6:21pm
Forum: E-Bike Technical
Topic: samsung 40t 21700
Replies: 6
Views: 520

Re: samsung 40t 21700

I’m using the US21700 VTC6A which is similar in a 4P configuration- no trouble putting out 50A peaks. 3P would be enough but that’s only going to be 12Ah - not a huge range potentially. Also any cell used at high C rate 3C+ might have a reduced cycle life
by electric_nz
Dec 24 2019 3:48am
Forum: Battery Technology
Topic: Awesome study / information on NCA battery degradation (Panasonic NCR18650PD)
Replies: 18
Views: 1449

Re: Awesome study / information on NCA battery degradation (Panasonic NCR18650PD)

Random data point- cells from a 14s5p battery of Panasonic NCR18650A after 150 cycles of 90% to 30% showed almost no degradation of either capacity (approx loss 50mah) or internal resistance (identical according to charger). This was despite being used at 2C discharge with peaks of 3C, and a charge ...
by electric_nz
Dec 16 2019 2:18pm
Forum: Battery Technology
Topic: Sanyo 18650GA fakes?
Replies: 11
Views: 903

Re: Sanyo 18650GA fakes?

Many batteries have few if any markings as they are meant for the wholesale market and are put in laptop batteries or appliances, not sold to the general public. It looks like the genuine article, see https://eu.nkon.nl/sanyo-18650ga.html Sanyo batteries often have the model number faintly etched in...
by electric_nz
Dec 01 2019 2:22am
Forum: Battery Technology
Topic: 14s6p pack design
Replies: 8
Views: 984

Re: 14s6p pack design

You should try and mount the bags forward of the rear axle otherwise it will be a wheelie machine to the point of ridiculousness. Otherwise a counterweight over the front wheel will be necessary- or lean forward when starting out, up a hill, etc.
by electric_nz
Dec 01 2019 2:11am
Forum: Battery Technology
Topic: Resuscitating new Vtc6a from complete discharge
Replies: 7
Views: 961

Re: Resuscitating new Vtc6a from complete discharge

Thanks for the responses, I think I’ll follow the spec sheet. I have easily enough cells measuring 3-4v for a 14s4p pack, and will keep any of the rest above 1V for spares. Any below 1V will be binned. A low risk maybe but high consequences as many have pointed out. Thanks
by electric_nz
Nov 29 2019 3:11pm
Forum: Battery Technology
Topic: Resuscitating new Vtc6a from complete discharge
Replies: 7
Views: 961

Resuscitating new Vtc6a from complete discharge

So I lucked out and bought a bulk lot of scrapped battery packs containing US21700VTC6A for approx $2 per cell. They are date code 2019 and cells measure consistently on each pack, suspect the battery packs were scrapped due to faulty BMS rather than cells. Most of the packs measure around 3-4V per ...
by electric_nz
Oct 27 2019 11:53pm
Forum: Battery Technology
Topic: Using Donor LIPO Cells with Individual Integrated BMS Per Cell for a DIY Pack?
Replies: 48
Views: 2813

Re: DIY Battery Pack Donor Cell Candidate Question

Yes the silver bags are the cells - don’t open them unless you want smoke!! From the picture, looks like each pack is made 4 individual silver cells of about 2500mah, with + and - wires for each brought out to the connector. That’s very good news and means You can draw 1C or 10A from a single pack a...
by electric_nz
Oct 27 2019 1:36pm
Forum: Battery Technology
Topic: Using Donor LIPO Cells with Individual Integrated BMS Per Cell for a DIY Pack?
Replies: 48
Views: 2813

Re: DIY Battery Pack Donor Cell Candidate Question

Looking at the connectors and wiring, I would guess they are rated for a low ish draw. Maybe have a look at the published power draw and battery life of the intended device to see if you can get some numbers. Laptops often have 3-4 cells in series and 2-3 parallel. If you’re running a 1000W motor at...
by electric_nz
Oct 25 2019 3:38pm
Forum: Battery Technology
Topic: Using Donor LIPO Cells with Individual Integrated BMS Per Cell for a DIY Pack?
Replies: 48
Views: 2813

Re: DIY Battery Pack Donor Cell Candidate Question

Good score- how many did you get? I’m powering a bike with new old stock Panasonic toughbook batteries with great results. Key thing to recognise is that these are cells that are meant for lower current, high capacity use; so voltage will sag under high current. To get around this have as many in pa...
by electric_nz
Oct 19 2019 7:09pm
Forum: E-Bike Non-hub Motor Drives
Topic: Can the Cyclone 3000 Handle a 24s Pack ( 100 volts ) ?
Replies: 11
Views: 928

Re: Can the Cyclone 3000 Handle a 24s Pack ( 100 volts ) ?

In a related question, if you are after acceleration rather than top speed, is it better to use a 14S with more parallel strings for higher current delivery and low sag; or 20s with fewer parallel strings for higher voltage? Looking to maximise the off the line surge that makes evokes so much fun ar...