Search found 4887 matches

by izeman
Jul 12 2019 3:11pm
Forum: Motor Technology
Topic: how to fan cool a controller?
Replies: 16
Views: 1201

Re: how to fan cool a controller?

spinningmagnets wrote:
Jul 12 2019 1:59pm
Ha ha! I didn't look at the date...
:bigthumb: 8) :lol:
by izeman
Jul 12 2019 11:46am
Forum: Motor Technology
Topic: how to fan cool a controller?
Replies: 16
Views: 1201

Re: how to fan cool a controller?

I would use two server-computer fans that are designed to run off of 48V (one pushing, one pulling). For a 72V system I would run three 24V fans in series. The centrifugal style will push more air than an axial, and look for a fan model that has ball bearings. Really? One of my first thread in 2013...
by izeman
Jul 09 2019 1:08pm
Forum: Battery Technology
Topic: Build a mini USV/UPS
Replies: 42
Views: 1005

Re: Build a mini USV/UPS

Here are the pics. I also did a 4A load test (~550mA per cell fuse). They didn't get warm at all. So at least they will survive normal operation. :)

IMG_1712.JPG
IMG_1712.JPG (66.55 KiB) Viewed 60 times
IMG_1713.JPG
by izeman
Jul 09 2019 11:41am
Forum: Battery Technology
Topic: Build a mini USV/UPS
Replies: 42
Views: 1005

Re: Build a mini USV/UPS

I did a redesign with "fuses" in between. And I agree with you. I'm not sure the fuses will blow in EVERY situation. There may be situation where they should work and others where just all the fuses and the main connection may become hot and nothing else happens. That's why i now made the parallel c...
by izeman
Jul 08 2019 5:06pm
Forum: Battery Technology
Topic: Build a mini USV/UPS
Replies: 42
Views: 1005

Re: Build a mini USV/UPS

Oh man. I feel REALLY stupid. This will NOT work. :oops:
Just went down to check state of charge and thought ... "HAEHHH?? How is this supposed to work in case of cell failure?!". It CAN'T, as the cell is connected to it's neighbors via a solid nickel strip. DAMN.
I have to do it all again :lol:
by izeman
Jul 08 2019 2:55pm
Forum: Battery Technology
Topic: Build a mini USV/UPS
Replies: 42
Views: 1005

Re: Build a mini USV/UPS

Printed the cell holders yesterday and welded the cells in today. Took 10min. Then the BMS was installed. It's a 40A type. WAY over sized, but I had it at home, and it fits nicely. So i installed it. Took some pictures of the whole pack. It's completly different than normal ebike packs. Parallel str...
by izeman
Jul 06 2019 11:01am
Forum: E-Bike Reviews & Testing
Topic: Cycle Analyst V3 preview and first beta release
Replies: 4481
Views: 679741

Re: Cycle Analyst V3 preview and first beta release

Hmm. What shall i say. Tried it again, raising the Vout a tiny bit (just 50mV). And it seems to work just fine. If the wheel is at a stop, and you lift the bike, the wheel won't start to turn, but if you then add throttle it keeps spinning at a modest speed and consumes around 50-70W. Will need to t...
by izeman
Jul 06 2019 6:33am
Forum: E-Bike Reviews & Testing
Topic: Cycle Analyst V3 preview and first beta release
Replies: 4481
Views: 679741

Re: Cycle Analyst V3 preview and first beta release

What you can do is use the ebrake out voltage as a way to make the controller actually shut off when you are stopped etc, and then otherwise without the ebrake line active then there is always a min throttle out signal commanding just a small amount of torque from the hub. That was my first idea to...
by izeman
Jul 04 2019 4:46pm
Forum: E-Bike Reviews & Testing
Topic: Cycle Analyst V3 preview and first beta release
Replies: 4481
Views: 679741

Re: Cycle Analyst V3 preview and first beta release

It's generally difficult for the CA3 itself to regulate constant lower power levels in the 10-30 watt range with conventional PWM based motor controllers. If you do have a mid-drive setup that you want to try this on and have a regular controller rather than a phaserunner, try setting a lower power...
by izeman
Jul 04 2019 5:17am
Forum: E-Bike Reviews & Testing
Topic: Cycle Analyst V3 preview and first beta release
Replies: 4481
Views: 679741

Re: Cycle Analyst V3 preview and first beta release

There were a number of reasons for this but one of them came down to limited eeprom memory space for additional parameters as we added all the new features in CA3.1 (like digi-aux)... Btw, as you wrote that: Is there a planned feature list for new firmwares? Is CA3 still developed? You may remember...
by izeman
Jul 04 2019 5:11am
Forum: E-Bike Reviews & Testing
Topic: Cycle Analyst V3 preview and first beta release
Replies: 4481
Views: 679741

Re: Cycle Analyst V3 preview and first beta release

So almost all of these mystery behaviors and inconsistent performances of the CA3's torque PAS mode with the Sempu BBs seems to be from a bad batch of sensors. What we would see on probing devices on our end is that the torque signal would often end up randomly going to either 0V (resulting in nega...
by izeman
Jun 27 2019 10:39am
Forum: E-Bike Non-hub Motor Drives
Topic: Converting a hubmotor to a middrivemotor
Replies: 988
Views: 183144

Re: Converting a hubmotor to a middrivemotor

crossbreak wrote:
Jun 27 2019 10:25am
since the BBSHD exist, this is somehow outdated
You call my bike WHHHHAAAATTTT? :lol:
by izeman
Jun 26 2019 4:57am
Forum: Items for Sale - New
Topic: Wholesale 18650 cells (NEW) for UK/EU
Replies: 30
Views: 1158

Re: Wholesale 18650 cells for UK/EU

brumbrum wrote:
Jun 22 2019 8:46am
Nkon has a flat rate of postage of around £12.00 which is pretty good if buying 200 cells
And very reasonable p&p for small amounts (~10) of cells. Just a few € for shipping inside Europe.
by izeman
Jun 26 2019 4:48am
Forum: Battery Technology
Topic: First battery pack build, does my design look OK?
Replies: 3
Views: 217

Re: First battery pack build, does my design look OK?

Yes. Design looks good. And as jonescg said: Try to spread the load of the main wires across the whole lenght of the nickel. Soldering in between welding spots is a good way to do it.
And: No need to quote the WHOLE post, bloats up everything. We are able to follow this thread anyway ;)
by izeman
Jun 25 2019 6:54am
Forum: Battery Technology
Topic: Thin nickle strips as cell fuse?
Replies: 3
Views: 210

Re: Thin nickle strips as cell fuse?

Btw: Just found this link in another thread, but I'll repost it here as well:

https://www.powerstream.com/wire-fusing-currents.htm

Very helpful!!
by izeman
Jun 25 2019 3:06am
Forum: Battery Technology
Topic: UNRC UN-A6 plus question
Replies: 4
Views: 150

Re: UNRC UN-A6 plus question

I started the discharge before i went to bed and it still showed all discharge values until this morning.
So i can confirm that it works like it should. Super convenient to test several cells at the same time. One charge & discharge cycle takes around 4h.
by izeman
Jun 24 2019 2:29pm
Forum: Battery Technology
Topic: UNRC UN-A6 plus question
Replies: 4
Views: 150

Re: UNRC UN-A6 plus question

Studying the "unofficial manual" i found this: Screenshot from 2019-06-24 21-27-23.png I don't have an parameter "Eb", but I got "Ad". This was set to "1". I set it to "0" and now the charger doesn't start charge automatically as soon as you plug in a battery. Seems to work, as it kept showing "mAh"...
by izeman
Jun 24 2019 2:21pm
Forum: Battery Technology
Topic: UNRC UN-A6 plus question
Replies: 4
Views: 150

Re: UNRC UN-A6 plus question

john61ct wrote:
Jun 24 2019 2:16pm
No but I've seen posts where they set up a smartphone camera to take pics every x minutes or seconds
HAHA :lol: 8)
by izeman
Jun 24 2019 2:20pm
Forum: Battery Technology
Topic: Thin nickle strips as cell fuse?
Replies: 3
Views: 210

Thin nickle strips as cell fuse?

I got this table for PCBs:

Screenshot from 2019-06-24 21-17-51.png
Screenshot from 2019-06-24 21-17-51.png (8.82 KiB) Viewed 127 times

If I take 35um = 0,035 x 0,25 mm = 0,00875 mm2 this gives 0,8A and 20K above ambient for the strip.
So a copper of 0,005 may become 30K above ambient?

EDIT : see last post for correct calculation
by izeman
Jun 24 2019 2:10pm
Forum: Battery Technology
Topic: Thin nickle strips as cell fuse?
Replies: 3
Views: 210

Thin nickle strips as cell fuse?

Making the calcs is quite hard. 0,15 x 0,15 = 0,0225 mm2. BUT it's nickle, so copper equivalent of 0,005 mm2. Can't even find tables that list the maximum safe amps for that :lol: 8) EDIT: Stupid me: It's 0.15 x 1.5 = 0.22 mm2. That's 10 times of what i had first. And i read that 1 mm2 of nickel is ...
by izeman
Jun 24 2019 2:04pm
Forum: Battery Technology
Topic: Thin nickle strips as cell fuse?
Replies: 3
Views: 210

Thin nickle strips as cell fuse?

I'm building a 3s6p pack for a mini UPS, and I'd like to fuse individual cells as those are refurbished ones. So I did a test with a 0.15mm thick and around 1.5-2mm wide mini strip. Short circuited it, no sparks, just a glow in a fraction of a second and the fuse was blown. The pack will only see 4A...
by izeman
Jun 24 2019 12:02pm
Forum: Battery Technology
Topic: UNRC UN-A6 plus question
Replies: 4
Views: 150

UNRC UN-A6 plus question

For years now i have one of these balance chargers, and i like to use it. Now I'm in need to check several 18650 cells for capacity. Adding a 6s charging harness with 6 cell holders makes checking several cells at the same time easy. BUT there is a big issue with this charger. During charge and disc...
by izeman
Jun 22 2019 7:20am
Forum: Vendor Relations Corner
Topic: Experience with ebikeparts.at
Replies: 2
Views: 158

Re: Experience with ebikeparts.at

Thanks for sharing that. It's always good to hear good feedback as well, as it's almost always the bad stuff that's talked about. :thumb:
by izeman
Jun 21 2019 10:19am
Forum: Battery Technology
Topic: Build a mini USV/UPS
Replies: 42
Views: 1005

Re: Build a mini USV/UPS

PoE gear can be very cheap What do you mean by that? I've got some ubiquity wifi stuff here, where APs are PoE powered. So the UPS will include two 24V PoE injectors as well. So basically it will take 12V DC and convert/stabilize it to 12V (ubiquity, cable modem, switch, home security gear), 24V (P...
by izeman
Jun 21 2019 5:07am
Forum: Battery Technology
Topic: Build a mini USV/UPS
Replies: 42
Views: 1005

Re: Build a mini USV/UPS

Looks like a nice little PCB, but i guess this would not be very energy efficiant? Power input 5V, output 12V. Power output current is quite small as well, so every device would need a seperate one? Any each off them will be powered by a seperate 5V power supply? But it's for sure a good choice for ...