Search found 18 matches

by Boobyjohn
Jul 05 2017 12:59pm
Forum: Battery Technology
Topic: New Samsung cell 33G
Replies: 34
Views: 7569

Re: New Samsung cell 33G

I have the 14S9P triangle pack from EM3EV, with 33G cells inside. At least that is what I ordered; I haven't dared pull the pack apart to actually check. :) My setup is a BBS02, derated to 18A, so not a high power setup by ES standards. My daily commute is 30 km each way, i.e., 60 km roundtrip, on p...
by Boobyjohn
Feb 20 2017 3:44pm
Forum: Items for Sale - New
Topic: 18650 Spacers for DIY Builds
Replies: 6
Views: 1591

Re: 18650 Spacers for DIY Builds

@brumbrum I see your point, but ABS filament (material used by the printer) is approx 25 EUR for 1 kg. Spacers for a 20S 30Ah pack would probably weigh in at ~400 grams total (depending on layout), which is 12 EUR just for printing materials. Then you have to factor in labor, printer maintenance, el...
by Boobyjohn
Feb 20 2017 3:12pm
Forum: Items for Sale - New
Topic: 18650 Spacers for DIY Builds
Replies: 6
Views: 1591

18650 Spacers for DIY Builds

Hi all I have designed a few spacers like the one in the below pictures, which I am happy to offer to people on here. The spacers provide a nice snug fit to 18650 cells (also shown in one picture), with a minimal spacing between cells of 1 mm. Please note, the spacers shown assume that each parallel...
by Boobyjohn
Feb 03 2017 1:01am
Forum: Items for Sale - New
Topic: 6pence Resistance Spot Welder
Replies: 190
Views: 39330

Re: 6pence Resistance Spot Welder

@fechter I will just maintain a list of voltage sags for the last 20 (or so) welds and compute the average voltage sag using that list (first discarding highest and lowest value). If the voltage sag is more than 10% (or some other percentage) off, the main pulse is aborted. Each time the pulse one p...
by Boobyjohn
Feb 02 2017 3:20pm
Forum: Battery Technology
Topic: Critique this 3D Printed Battery - 14S10P 29E
Replies: 9
Views: 1483

Re: Critique this 3D Printed Battery - 14S10P 29E

Just had the middle section printed. Images (cells are 18650): https://goo.gl/photos/ArRC8UpAtrmSJg8g8 On the last picture, notice the threaded nut that fits (very tightly) into the center hole. Bolts with countersunk heads will go through the side plates into this nut from either side, which will (...
by Boobyjohn
Feb 02 2017 1:16pm
Forum: Items for Sale - New
Topic: 6pence Resistance Spot Welder
Replies: 190
Views: 39330

Re: 6pence Resistance Spot Welder

@fechter You *only* need to measure voltage sag. The rest will be consistent as long as the battery isn't exchanged. Entering weld energy should be done by proxy, i.e., "that amount of time given this amount of sag". This cuts parts involved in half. I'm not sure how useful or necessary th...
by Boobyjohn
Feb 01 2017 1:14am
Forum: Items for Sale - New
Topic: 6pence Resistance Spot Welder
Replies: 190
Views: 39330

Re: 6pence Resistance Spot Welder

@fechter Processor and sampling is fast enough. The highest reported sampling rate is 75 kHz or a sample every 13 microseconds [1], and processor chugs along at 16 MHz. At these speeds, I think signal latency is going to be a factor as we approach these limits. Do you c the problem? :) Edit: Old phy...
by Boobyjohn
Feb 01 2017 12:23am
Forum: Items for Sale - New
Topic: 6pence Resistance Spot Welder
Replies: 190
Views: 39330

Re: 6pence Resistance Spot Welder

So I have been brewing on a fairly simple extension to this welder: "Probe" preparation welds. The idea with this post is just to throw the idea out there. Hopefully, someone with more experience with spot welding will comment on the feasibility and utility of the proposal. The electronic ...
by Boobyjohn
Jan 30 2017 10:52am
Forum: Battery Technology
Topic: Critique this 3D Printed Battery - 14S10P 29E
Replies: 9
Views: 1483

Re: Critique this 3D Printed Battery - 14S10P 29E

@ScooterMan101

I don't disagree with that, but I'm not really at risk since I don't own a 3D printer. I just use online services such as 3dhubs. Usually, there is local provider who is not that expensive. Similarly for laser cutting.
by Boobyjohn
Jan 29 2017 4:07pm
Forum: Battery Technology
Topic: Critique this 3D Printed Battery - 14S10P 29E
Replies: 9
Views: 1483

Re: Critique this 3D Printed Battery - 14S10P 29E

@Skrzypas thank you for your suggestions. I finally decided that I really value a no-nonsense battery in day-to-day operations. Hence I decided to go with a BMS and satiator. BMS will be the tinyBMS from circuit, the 30A cont' version. (My max controller max current is currently 18A, so plenty of ma...
by Boobyjohn
Jan 23 2017 2:27pm
Forum: Items for Sale - New
Topic: 6pence Resistance Spot Welder
Replies: 190
Views: 39330

Re: 6pence Resistance Spot Welder

The exciting news is this. One of the power boards I'm building up is for Boobyjohn in Denmark. He has a crazy number of hours of coding experience, including embedded systems, and has kindly offered to refactor the code with me. It will take a little time yet till we have something we are happy to...
by Boobyjohn
Jan 23 2017 1:47pm
Forum: Battery Technology
Topic: Critique this 3D Printed Battery - 14S10P 29E
Replies: 9
Views: 1483

Re: Critique this 3D Printed Battery - 14S10P 29E

@whereswally606: The Graupner Polaron Pro looks like it fits the bill. However, buying a high-quality BMS (e.g. TinyBMS from circuit on here) + cycle satiator is cheaper, and will be less of a hassle in day-to-day operations. Hmm. I guess TinyBMS + satiator will be my way...
by Boobyjohn
Jan 22 2017 2:13pm
Forum: Battery Technology
Topic: Critique this 3D Printed Battery - 14S10P 29E
Replies: 9
Views: 1483

Critique this 3D Printed Battery - 14S10P 29E

Hi all Long time lurker; been reading on here for more than 4 years now. As such, I find that it is reasonable now to start on the battery building adventure. :) I plan on doing a 14S10P build for my ebike commuter. I recently (10 months ago) switched jobs, which extended my commute a fair bit: 28 k...
by Boobyjohn
Nov 09 2016 3:31pm
Forum: Items for Sale - Used
Topic: [EU] Complete bike (1500w) 9C, 12 fet, 14s25ah
Replies: 3
Views: 994

Re: [EU] Complete bike (1500w) 9C, 12 fet, 14s25ah

Are you willing to sell the battery parts individually?

In that case, I'd like to take the battery, charger, and battery bag of your hands.

How old is the battery?
How many cycles do you estimate the battery has had?
At what voltage (and temperature) has it been stored in garage?
by Boobyjohn
Jul 05 2015 6:57am
Forum: EBike Non-hub Motor Drives
Topic: Bewo, New Crank-drive Motor
Replies: 257
Views: 76226

Re: New Crank-drive Motor

eMax wrote:I would definitely say the BEWO is noisier. It uses all metal gearing...
Thank you for the reply, but I am a bit disappointed. The BBS01 also has a metal-metal gear, so I hoped that the sine-wave controller would make it noticeable less loud.

The quest for a silent mid-drive continues...
by Boobyjohn
Jun 30 2015 3:26am
Forum: EBike Non-hub Motor Drives
Topic: Bewo, New Crank-drive Motor
Replies: 257
Views: 76226

Re: New Crank-drive Motor

I have been running this kit for a while now at 36v500w. Seems solid and decent 12-15Wh/km efficiency is being achieved on most rides. In comparison a BBS01 getting 9/10. Great info. Could you compare the bbs01 and bewo kit a bit more? In particular, I would like to know whether the bewo kit is mor...
by Boobyjohn
Jun 13 2015 1:44pm
Forum: EBike Non-hub Motor Drives
Topic: BBS0X - Assembly order of bottom bracket
Replies: 1
Views: 324

BBS0X - Assembly order of bottom bracket

Hello all I am the happy owner of a BBS01 middrive unit. So far the drive have pushed me 2400 km, without too many problems. However, I have the issue below that, after several hours of searching through this forum, I cannot find answered anywhere. My problem is that I took the bottom bracket apart ...