Search found 1162 matches

by whatever
Jul 25 2020 5:36am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

research article just showing using optic fibres for infrared temp measurements
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3028499/
by whatever
Jul 21 2020 1:30pm
Forum: Battery Technology
Topic: Tesla video (with interesting shots)
Replies: 1
Views: 159

Re: Tesla video (with interesting shots)

it might just be one step in the production process, not the final layout. It would be nice to see a video detailing all steps in production. Not likely though.
Having thousands of cells does seem a very complicated way of making a pack.
by whatever
Jun 26 2020 2:24am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

cell temp screen.jpg
cell temp screen.jpg (124.07 KiB) Viewed 161 times
imagined screen output of all cells, each block of cells can be shown in more details as pic on right side.
max/min/average temps etc could be shown on same screen.
by whatever
Jun 26 2020 12:36am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

ok one step further:
lets say a tesla style pack is made such that the cells can be popped in and out of the pack easily, with an all cell temp monitor, you might be able to just take out bad cells and put in new ones at certain intervals or when necessary.
by whatever
Jun 26 2020 12:31am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

since tesla already has wealth of knowledge on using cameras for autopilot, it would be no problem to use camera output from a flir screen to analyse cell state of health, parallel cells would no longer be invisible. If any cell went to a critical temp point just before thermal runaway, complete pac...
by whatever
Jun 26 2020 12:26am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

a few more thoughts on the topic: for ebikes, you could use optic fibres, there are larger diameter ones used in pool lighting etc, pretty cheap on ebay. Say you had 14 cells, you could direct 14 optic fibres to a flir camera, and you would have real time temp monitor of all cells. Back to tesla lar...
by whatever
Jun 25 2020 7:45am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

here is the original research paper, note the first diagram, pretty much sums it up, it is very much possible to do it. https://www.osapublishing.org/DirectPDFAccess/32DCB5CE-9F8A-473C-8FBA80E734A13307_403007/ome-9-1-128.pdf?da=1&id=403007&seq=0&mobile=no I suspect if the plastic tesla has used on i...
by whatever
Jun 25 2020 7:35am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

seems I aint so crazy afterall, some researches have achieved similar process in area of biomedical research, using exactly this idea ( well very similar) see https://physicsworld.com/a/tiny-light-guides-could-enhance-biomedical-devices/ they managed to produce lightguies 50microns in size, now that...
by whatever
Jun 25 2020 7:24am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

did a fair bit of research on tesla patents, cant find one with same idea. Just to think outloud a bit on the idea: My thought is that if you were to melt some plastic material with a laser, it may be possible to make a pathway for a lightguide. I'm guessing the melted plastic as it cools with have ...
by whatever
Jun 21 2020 5:23am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

tesla has a patent on this method? interesting, it seems logical step to go towards.
I'll see if I can find it
by whatever
Jun 10 2020 8:31am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

Re: parallel cells battery monitor idea

just a few more thoughts: monitoring temperature of packs, I mean monitoring individual cell temps has not really been possible, too much wiring complexity for thermocouples, the only solution thus far seems to be thermal camera on packs where all cells are visible. I guess what i'm suggesting is to...
by whatever
Jun 05 2020 7:18am
Forum: Battery Technology
Topic: parallel cells battery monitor idea
Replies: 11
Views: 391

parallel cells battery monitor idea

just trying to think of some way to monitor a very large array of cells such as tesla pack for temperature. Some simple way to identify if any cells temperature goes too high. Came up with one idea that might work as follows. Model S battery pack has a plastic cover ( clear ) over the cells as seen ...
by whatever
May 31 2020 3:02am
Forum: Battery Technology
Topic: diy bms stuart pittaway
Replies: 9
Views: 346

Re: diy bms stuart pittaway

regarding how to read parallel cells that have gone bad. Here one guy uses an infrared thermal camera to find which cell has gone bad ( no need to dismantle the packs) see youtube vid at 7:06 min. This is probably the only way to do it at the moment, without taking pack apart. Interestingly he cant ...
by whatever
May 27 2020 5:17am
Forum: Battery Technology
Topic: novel method battery discharge
Replies: 2
Views: 423

Re: novel method battery discharge

thanks for that, points taken on board
by whatever
May 26 2020 1:08pm
Forum: Battery Technology
Topic: formation charge of sei layer in lithiums
Replies: 0
Views: 75

formation charge of sei layer in lithiums

just looking into formation charging regimes for nmc type lithiums. an interesting paper showing how to shorten formation charging times can be seen here: https://www.sciencedirect.com/science/article/pii/S0378775317300113 this pic sums up the method https://ars.els-cdn.com/content/image/1-s2.0-S037...
by whatever
May 26 2020 12:58pm
Forum: Battery Technology
Topic: diy bms stuart pittaway
Replies: 9
Views: 346

Re: diy bms stuart pittaway

you could set different variables for each series group, lets say one group has a bad cell, you might want to take it easy on that group and set lvc higher, all sorts of situations could be dealt with. You say its not possible to monitor parallel cells individually they have to be atomised, yes that...
by whatever
May 25 2020 12:17pm
Forum: Battery Technology
Topic: diy bms stuart pittaway
Replies: 9
Views: 346

Re: diy bms stuart pittaway

every bms allows you to adjust/monitor each group of series cells individually....me thinks not.
that is the challenge ahead: how to monitor cells in parallel
by whatever
May 25 2020 12:14pm
Forum: Battery Technology
Topic: novel method battery discharge
Replies: 2
Views: 423

novel method battery discharge

this guy has a really good method for discharging a battery using a high power mosfet in water,
using one mosfet he discharges 1kw
might be useful for high current discharge tests
https://www.youtube.com/watch?v=QzdIjkh ... e=youtu.be
by whatever
May 25 2020 3:24am
Forum: Battery Technology
Topic: diy bms stuart pittaway
Replies: 9
Views: 346

Re: diy bms stuart pittaway

lets say you have 7 lithiums in series, number of parallel in each group can be quite large example: 7s20p ( using 18560 or similar), each group is individually monitored. Number of groups in series can also be a large number. Each bms board can control each group ( balance, lvc etc), each board is ...
by whatever
May 24 2020 7:50am
Forum: Battery Technology
Topic: diy bms stuart pittaway
Replies: 9
Views: 346

diy bms stuart pittaway

just doing a bit of research on powerwall style battery pack, and came across some really nice diy bms boards, very suitable for ebike applications. Pretty much an cheap alternative to something like Batrium. Anyone else had any experience with these? this video shows how they are used https://www.y...
by whatever
Mar 28 2020 8:26am
Forum: Battery Technology
Topic: 48v 20ahr aliexpress jungla brand
Replies: 5
Views: 301

Re: 48v 20ahr aliexpress jungla brand

thought it looked a bit good to be true, adivice taken, thanks guys
by whatever
Mar 25 2020 11:39am
Forum: E-Bike General Discussion
Topic: celllog not in production anymore
Replies: 38
Views: 2617

Re: celllog not in production anymore

yup thats the one, with alarm
by whatever
Mar 25 2020 11:37am
Forum: Battery Technology
Topic: 48v 20ahr aliexpress jungla brand
Replies: 5
Views: 301

48v 20ahr aliexpress jungla brand

anyone experience with these, they are cheap
https://www.aliexpress.com/item/4000596239155.html
by whatever
Mar 03 2020 8:29am
Forum: E-Bike General Discussion
Topic: celllog not in production anymore
Replies: 38
Views: 2617

Re: celllog not in production anymore

dont forget the dvm-8s
pretty much a clone of celllog but slightly bigger screen, also has backlight
bvm 8s cell log clone.jpg
bvm 8s cell log clone.jpg (28.61 KiB) Viewed 831 times
by whatever
Feb 28 2020 3:10am
Forum: General Discussion
Topic: antonio zonardo italy
Replies: 0
Views: 1803

antonio zonardo italy

if your still on this forum antonio, your email has been hacked, or someone pretending to be you, just got an email that said it was from you but it linked to some scammers site.