Search found 137 matches

by soyachips
Tue, 25 Jun 2019, 18:31
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

OK some things I’ve learnt while waiting for parts to arrive ... aluminium is 61% as conductive as copper but that’s pure aluminium which is quite soft so it’s alloyed with other elements to make it stronger. Most common aluminium is only around 50% as conductive as copper so as jonescg said at the ...
by soyachips
Fri, 21 Jun 2019, 20:28
Forum: Members Machines
Topic: Michael's Lotus Elise
Replies: 6
Views: 437

Re: Michael's Lotus Elise

Super exciting project. Can’t wait to see how it all works out. Out of interest where did you get the Leaf modules from? I wouldn’t mind using them in my project
by soyachips
Wed, 19 Jun 2019, 20:11
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Thanks for all the suggestions everyone. jonescg I had no idea you could get copper cut so cheap. That's like 1/2 the price I could find on eBay just for the material! Who's your supplier? I actually jumped the gun the other night after deciding to go with aluminium and bought some spacers from here...
by soyachips
Mon, 17 Jun 2019, 19:06
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

brendon_m wrote:
Mon, 17 Jun 2019, 18:17
A lot of the cells are in parallel so each cell only sees a small portion of the current.
Each of your cells will see 1/2 the total current but from 1 pair of cells to next will be the whole kabootle
Got it, thanks for clarifying!
by soyachips
Mon, 17 Jun 2019, 19:06
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Richo wrote:
Mon, 17 Jun 2019, 13:25
Stuff the bending - I'd go with M4 Metal spacers NPB F-F and just bolt the different height busbars together.

What's the height difference?
The height difference is 15mm but there is up to 2mm variation so keeping the bars flat would handle the variations better and be a lot less work!
by soyachips
Mon, 17 Jun 2019, 18:15
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Dan007a wrote:
Mon, 17 Jun 2019, 17:06
Have 25mmx4mm ali.
Fyi. Make sure your nuts are tight. Ali gets very very hot if loose.
Thanks that’s a very good tip! I guess that happens with all materials though right?
by soyachips
Mon, 17 Jun 2019, 18:14
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Regarding full current going through the interconnects, I keep thinking about those battery packs made up of lots of 18650 laptop cells and wondering how they get away with using small/thin tabs between the cells? What am I missing?
by soyachips
Mon, 17 Jun 2019, 06:45
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

brendon_m wrote:
Sat, 15 Jun 2019, 07:23
But it will be harder to bend because it'll be thicker
I’m going to try using 25mm x 3mm thick aluminium bar and just bought one of these vice brakes to do the bending. Will post the results here.

https://www.machineryhouse.com.au/V050
by soyachips
Mon, 17 Jun 2019, 06:40
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Use some noalox to stop the aluminium from corroding at the connections. Thanks I’ve seen a lot of people using this. I’ve also seen people using Chemtools R006 which is a conductive carbon grease. Any thoughts on the pros and cons of both? Shame you couldn’t use the plates you had made up! What wa...
by soyachips
Mon, 17 Jun 2019, 06:30
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Adverse Effects wrote:
Sat, 15 Jun 2019, 07:27
would this type of connector be better?
Thanks I may end up using something like this if I can’t get solid bars to work.
by soyachips
Sat, 15 Jun 2019, 06:22
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Is the plan to have a square on the bottom that's 2 holes x2 holes and strips that bend up and down across the top that are 4x1? Or maybe 4x1 strips along the bottom with 2x1s on top joining 2 10ah cells and separate one for 15ah cells? I’m still working that out as well as some way to bend the met...
by soyachips
Sat, 15 Jun 2019, 06:14
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Re brendon m's comment on cu vs al, don't remember much from my '68 army apprenticeship but I do remember that the figure being taught then was 62%. Still learning from this forum for my third conversion.thanks. I found this online: Aluminum has 61 percent of the conductivity of copper, but has onl...
by soyachips
Sat, 15 Jun 2019, 02:48
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

out of curiosity, what connector spacing are you looking at? That’s a great question! I may end up regretting this but I’ve ended up with 24 x 15Ah and 24 x 10Ah Headway cells that I’m putting together into a 24s2p kind of arrangement. Each 10Ah cell is “piggy backing” on a 15Ah cell using 3D print...
by soyachips
Fri, 14 Jun 2019, 22:37
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Wow that is a lot of holes!!! Actually just did a quick calculation and mine will be around 200 holes! :shock:

Thanks for the quick replies, great info and I might end up going down this path.
by soyachips
Fri, 14 Jun 2019, 22:20
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

Hmmm interesting. I’ve seen people using copper pipe before but thought the corrosion thing was an issue. Good to hear there’s a fix for that. So dielectric grease between each of the stacked sheets and then soft seal around the outside? Will you spray the soft seal on the interconnects before attac...
by soyachips
Fri, 14 Jun 2019, 22:01
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Re: Battery interconnect sizing

I was thinking aluminium mainly due to availability and partially cost. If I go with copper it needs to be tinned I believe and I was having trouble finding lengths of tinned copper flat bar. I need to make the interconnects myself as my pack is a slightly odd arrangement of cells! If you know of an...
by soyachips
Fri, 14 Jun 2019, 21:38
Forum: Batteries, charging, management and monitoring
Topic: Battery interconnect sizing
Replies: 48
Views: 1238

Battery interconnect sizing

I’m planning on making battery interconnects out of aluminium flat bar but not sure what thickness to use. I’ve seen people use multiple thin interconnects stacked on top of each other so I’m assuming the interconnects between each cell need to carry the same amount of current as the cables going fr...
by soyachips
Mon, 10 Jun 2019, 20:48
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

Put the new blocks into the existing swingarm, swapped the tyre over and got it all into the bike. Next step is to work out how to mount the batteries and controller inside the frame. Decided to push the bike home from the workshop and got some interesting shots on the way :D IMG_7072.jpg tyre.jpg I...
by soyachips
Mon, 10 Jun 2019, 20:40
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

Had some awesome help from Danny Ripperton (AEVA member) machining the swingarm blocks that hold the hub motor axle.


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The blocks are solid aluminium and weigh 344g each
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by soyachips
Fri, 31 May 2019, 17:51
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

francisco.shi wrote:
Fri, 31 May 2019, 10:50
Is that after it is assembled with the bus bars and holder?
No that’s just based on the specs of the cells. This is just a temporary pack that I’m using for testing. Still haven’t decided exactly what the final pack will be.
by soyachips
Fri, 31 May 2019, 17:04
Forum: For Sale/Wanted
Topic: WANTED: 72V charger for LiFePO4
Replies: 2
Views: 184

Re: WANTED: 72V charger for LiFePO4

Great, thanks for the link!!! :D
by soyachips
Fri, 31 May 2019, 09:38
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

francisco.shi wrote:
Fri, 31 May 2019, 07:32
What is the energy density of the finished battery pack? (Wh/kg)
According to the specs, the Headway 15ah are 105 Wh/kg
by soyachips
Thu, 30 May 2019, 22:33
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

One problem I've run into is the gap between the brake rotor and the motor is pretty small so the original brake caliper doesn't fit! IMG_7037.JPG I contacted QS Motor and they recommended a few from their catalog that would work. Ended up getting this one in grey. I'll need to get a new mounting br...
by soyachips
Thu, 30 May 2019, 22:18
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

I struggled trying to get the controller to do the angle identification setup and control the motor but got there in the end. I did swap the positions of the hall sensor A and C wires in the connector so they matched the controller connector side. That didn't seem to fix it straight away but after r...
by soyachips
Thu, 30 May 2019, 21:56
Forum: Members Machines
Topic: Soyachips’ Electric FZR250
Replies: 35
Views: 1698

Re: Soyachips’ Electric FZR250

Also put together a test battery pack using 24 x 15ah Headway cells to do some bench testing.
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