Search found 598 matches

by 4Springs
Fri, 27 Mar 2020, 18:31
Forum: Renewable Energy and Storage (Non-EV)
Topic: AVASS cells 2nd lot
Replies: 50
Views: 3775

Re: AVASS cells 2nd lot

For those that have manufactured custom links from rigid conductors, what materials and cross section dimensions do you recommend? Here are mine. You've reminded me that I haven't updated the thread describing my build for a while. IMG_20191004_172325964.jpg I used flattened copper pipe. I got it a...
by 4Springs
Fri, 27 Mar 2020, 16:00
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

This is what i did on my board but i found that when the bypass is running it warms up the board and that causes the sensor to detect a higher temperature. I placed the sensor very close to the contact and far away from. The hot parts of the bypass circuitry but it still detects a few degrees highe...
by 4Springs
Thu, 26 Mar 2020, 17:19
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

How did you attached the temperature sensors? When I did some testing for the first time I found that if the contact overheats the tab conducts the heat to the cell quite efficiently. The temperature sensors are on the celltop circuit boards - surface mount component very close to the negative term...
by 4Springs
Wed, 25 Mar 2020, 18:54
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 441
Views: 60264

Re: Low cost BMS

Do the nodes turn off or go into some low power mode to avoid discharging the battery when not being used? At 40% that means you generally bypass at about 0.24A? After doing the balancing yesterday I am starting to think that maybe 5A is an overkill. I have also dropped the max current to about 3A....
by 4Springs
Wed, 25 Mar 2020, 18:35
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

I'm not completely convinced that the Brumby has the full power that it used to. Neither is my wife, Zara, who took it into Launceston the other day. Mind you, we haven't driven it for a couple of months, and we've been driving our new Kona in the meantime. So perhaps we are just spoiled! One potent...
by 4Springs
Wed, 25 Mar 2020, 17:41
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

are you trying to drive on the pre-charge resistor only? Ah, I know what it is like to drive on the pre-charge resistor. This happens every time I forget to click around to 'Start' on the key. It goes 'eh', and just moves enough to tell me that it tried. This was giving me more than that, but not n...
by 4Springs
Wed, 25 Mar 2020, 16:12
Forum: Members Machines
Topic: Francisco's Electric Pajero
Replies: 133
Views: 15214

Re: Francisco's Electric Pajero

What voltage is considered 100% capacity? In other words, at what voltage does the cell voltage rise rapidly yet only a small current going into the cell. LFP and LYP cells will voltage balance quickly below fully charged but that has nothing to do with the state of charge being balanced. The only ...
by 4Springs
Tue, 24 Mar 2020, 18:23
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

So - how'd it go? As far as I know, nobody has tested these cells yet in a full-blown vehicle. And certainly nobody has tested my method for connecting them together into modules. My biggest fear is that the clamping arrangement that I developed won't take the current. IMG_0342.JPG The top and botto...
by 4Springs
Tue, 24 Mar 2020, 17:58
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

IMG_20200321_155657414.jpg Photo of the new-look underbonnet. The battery boxes are longer, thinner and shorter than before. The controller has been moved from the end to the top of the right battery box (left in the photo). The grey box with the red isolation switch has also been moved from the en...
by 4Springs
Tue, 24 Mar 2020, 17:45
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

IMG_20200301_093516174.jpg This photo shows the six rear battery modules in place. The blue string is to carry them with, and then tuck away once in place. All of the connections are at the tops of the modules. I've left the threaded rods on the shorter modules quite long still, with the idea that ...
by 4Springs
Tue, 24 Mar 2020, 17:32
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 441
Views: 60264

Re: Low cost BMS

I do a two point calibration and the master is the one that does all the calculations. In my BMS the nodes have very simple logic. To avoid any chance of the bypass flattening the cells the bypass only runs for a short time (which is settable by software) so if you stop sending the bypass command i...
by 4Springs
Mon, 23 Mar 2020, 18:32
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 441
Views: 60264

Re: Low cost BMS

New version of the Low Cost BMS - this one for the LG E63 NMC cells that Francisco has been importing https://forums.aeva.asn.au/viewtopic.php?f=17&t=5909 Since these cells have the terminals at each end, the old celltop board needed a bit of modification. This version bolts on to the negative termi...
by 4Springs
Mon, 23 Mar 2020, 17:33
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

IMG_0400.JPG Here are some battery modules, sitting in the tray since that is a handy place to put them. At the front are four of the large ones (30 cells), and towards the rear are two of the small ones (20 cells). One of the small modules has a yellow fuse holder on it. The holder takes a 30 A fu...
by 4Springs
Mon, 23 Mar 2020, 17:00
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

It has been a while since I've posted, but I have been very busy! I'll go back through my photos and make some posts in order of date.... IMG_0378.JPG I found four cells out of my 200 that had discolouration. The worst one is in the photo. It looks like something has leaked at some stage, but it is ...
by 4Springs
Mon, 23 Mar 2020, 16:53
Forum: Technical and conversion discussion
Topic: Prelude conversion project - some questions
Replies: 556
Views: 46989

Re: Prelude conversion project - some questions

jonescg wrote:
Mon, 23 Mar 2020, 14:33
So I'm thinking that the reservoir probably needs to be bigger, or a harder vacuum needs to be pulled.
What is the volume of your reservoir out of interest?
by 4Springs
Sat, 08 Feb 2020, 17:28
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

I'd go with the PET sheet because it gives you electrical isolation as well. The aim is the keep the cells above 0*C when charging and I believe the PET sheet will not conduct the cold from outside the way the aluminium would and therefore provide a more even heat. I've gone with the PET - mainly b...
by 4Springs
Sat, 01 Feb 2020, 13:58
Forum: Hyundai
Topic: Hyundai Kona road Noise
Replies: 13
Views: 743

Re: Hyundai Kona road Noise

Hi All, Within a week I sourced 2 rolls of Jaycar AX-3687 sound deadening and put it all around on the metal in the boot area and over the metal area just behind the back seat. I was careful to leave the plastic shield over the sticky mastic near any wiring, so the sound deadening did not stick to ...
by 4Springs
Fri, 31 Jan 2020, 18:35
Forum: Hyundai
Topic: KONA EV tailgate story
Replies: 12
Views: 669

Re: KONA EV tailgate story

Interesting. We don't have to slam ours. Might be able to be adjusted?
by 4Springs
Thu, 30 Jan 2020, 15:11
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

Ok, so I've done an experiment. It looks like I should put something between my Nichrome and my cells. The two options are plastic or aluminium sheet. Plastic is thinner, cheaper, an electrical insulator, easier to cut and less likely to damage the cells. But it is a relatively poor conductor of hea...
by 4Springs
Thu, 30 Jan 2020, 14:38
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

Could you use a heater element from a bag sealer? They are a thin strip about the thickness of the tape. I would expect the thickness to be thin enough that you will not mark the cells. They are pretty thin, I hadn't thought of them. Even though I got the idea of the PTFE sheet from my experience w...
by 4Springs
Thu, 30 Jan 2020, 13:12
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

I'd be reluctant to intentionally deform the surface of the cells. Is there not a flat tape version of the same stuff? Haven't found any, but that doesn't mean much. I've dismantled a module that has been assembled compressed for 5 days. IMG_0384.JPG IMG_0381.JPG I can feel the lines with my finger...
by 4Springs
Thu, 30 Jan 2020, 08:06
Forum: Members Machines
Topic: 4Springs' Brumby
Replies: 261
Views: 45128

Re: 4Springs' Brumby

I have been planning (and doing) something that I really should run past the educated folk here. I've made up heaters for my cells consisting of resistance wire. So like Nichrome, but a different metal. The idea is that I run wire up and back in a pattern, then sandwich this between cells. I'll hook...
by 4Springs
Mon, 27 Jan 2020, 18:33
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 441
Views: 60264

Re: Low cost BMS

Alternatively, the master can tell the CMUs what the average cell voltage is, and they can all bypass at that voltage, provided that voltage is above the rested 98% SoC value. Ah, now that is interesting. And something that I could implement... In my case the master tells each CMU when and how much...
by 4Springs
Mon, 27 Jan 2020, 18:24
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 441
Views: 60264

Re: Low cost BMS

The resistor type balancers work when the cell reaches X voltage and burns what ever value the resistors used can handle. That method relies on the charge current being reduced to less than the resistor burn off rate plus the load at the time ...... that would require accurate cell voltage monitori...
by 4Springs
Sun, 26 Jan 2020, 18:43
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 441
Views: 60264

Re: Low cost BMS

I presume daisy chain buss was selected to keep the wire length down, reducing noise pickup? You are still using 9600 baud? I copied the original design, so I didn't really choose. But daisy chain suits my vehicle, which has three separate battery boxes. If I used a spaghetti BMS then I'd most like...