Depends on the COVID chip world shortage
would love to know too. Trampa, ENNOID, FlexiBms, Nano 16s BMS all said they would drop awesome tiny bms so soon but still no one has actually done so… parts shortage is a bi_ch for real…
1 Like
In the process of resurrecting a FlexiBMSLite at the moment. In general it appears to be working, but maybe LTC chip might have sustained some damage.
Cell 1 shows voltage that is 0.006V below others, f.e. 3.640V, while other show 3.646V.
Measuring with a multimeter(UNI-T UT61E+) shows that all cells are around 3.648-3.649.
What flexi sees:
Cell 1: 3.640
Cell 2: 3.646
Cell 3: 3.645
Cell 4: 3.646
Cell 5: 3.645
Cell 6: 3.645
Cell 7: 3.645
Cell 8: 3.646
Cell 9: 3.646
Cell 10: 3.645
Cell 11: 3.646
Cell 12: 3.646
Actual measurements:
Cell 1: 3.648
Cell 2: 3.649
Cell 3: 3.648
Cell 4: 3.649
Cell 5: 3.648
Cell 6: 3.648
Cell 7: 3.648
Cell 8: 3.649
Cell 9: 3.649
Cell 10: 3.648
Cell 11: 3.649
Cell 12: 3.649
Firmware was reflashed, calibration values were entered.
What is responsible for cell voltage monitoring? Only the LTC chip or is there anything that can be shot inbetween?
is it still so? I was under impression that VESC now can have integration with BMS
Not yet. it scheduled for next VESC tool relics because tramper are bringing a bms to the market. Then every one will have to reprogram to try to incorporate it in to there firmware
IIRC the total measurement error for the LTC can be several mV. There might be another issue but those measurements are still within spec for the chip.
Hmm…wait…you mentioned calibration. If the calib. values are still correct then I’m not sure what’s up.
Do you have another multimeter you can use so we can confirm the issue with the board?
2 Likes
It was a combination of both LTC and 5V regulator. Both are out of stock everywhere. RIP lil Flexi that couldn’t. 
2 Likes
god dam it. this is nuts. how come all Chinese electronics still being produced and no issues… aliexpress is full of smart BMS and no one seems to care about WW shortage of anything
You should open up soon cheap Chinese electronics
Run out of fuses = use a bit of wire
Run out of filter = use a bit of solder
The amount of times thay just use any thing to hand if it turns in fit 3 seconds ship it out. Thay do not honer any money back guarantee.
2 Likes
I had a similar problem and figured out that on of the 121 resitors (R27) was burned. After replacing the resistor the values was good. maybe just coincidence but thought it might be worth posting here (please ignore the bad smd soldering)
2 Likes
I have gotten 100% of the claims on AliExpress resolved in my favour (well over 50 in past 10 years). do it right and do it timely and you will be covered. But that is not the question - safety is.
1 Like
Issue with them useing a old tracking number from a difrent package
Sending broken things back refusing to sign for return
Only 2 claims I try to make PayPal won’t refund me either. Credit card claim in the end
I never sent anything back. ever. Tracking has date and country of delivery. so they can’t just give you fake tracking. Also has not has happened once - always get correct package tracking.
when receiving package I open it and examine in one long video all in one take - never lost claim.
Do it right and you won’t loose
Not fake useing the same tracking number as other package. PayPal and Ali both say tracking number says delivered closed case.
Credit card takes both orderes and says it’s the same tracking number tells them to provide a real tracking number thay ignored it. I get my money back thay get charged extra fee for messing around
Just to back it up hears a video of some one taking a cheep chines product apart
again, tracking has delivery address where it was delivered. That information can be requested from postal service - once PayPal sees that tracking information delivered to wrong address case will be closed. glad you resolved it.
It is all about correct proo. 
Was the same address so that dose not work. because thay never provided tracking information to PayPal for other package PayPal just closed the case 4 times in there favor Ali just closed the case and said nothing.
I screen dumped Ali express website for both orders that had the tracking number and the customers declaration the credit card company voted in my faver as thay Ali dident even respond to them.
If you have hardware support/trouble requests/issues that I haven’t replied to in the forum’s PMs (because I haven’t been here for a while), please contact me via finnkotronics@gmail.com with your issue and also in the future. I want to have the customer communication through there and leave the forum PMs for forum talk to separate them.
So, I haven’t checked the forum for some time, haven’t really had anything positive to update you guys with and frankly didn’t feel like continuously dropping bad news…
Hardware manufacturing is currently stuck in component limbo and there is no saying when I can start to get critical components once again. MCUs are currently just marked with 100+ weeks lead time, in the first half of this year they were marked with 100 weeks, but now that “+” has been added couple months ago…
Note, please don’t ask about this next thing from me, I’ll inform when they’re going up. I have components for a couple dozen of the new 1.0 HW units, but I’m doing some development in the background for multiple things before they’re ready for sale.
There seems to be a couple open hardware support issues from a couple users, so I want to get those sorted out.
Overall
2021 hasn’t been kind. The year started very rough for me with a very scary situation after which things looked hopeful, but was soon followed by the one-two-combo knockout of realizing that I can’t actually actively pursue this road of mine of manufacturing my hardware design due to the component shortage problem. Didn’t have any other design either to develop or pursue.
Popped by the old office in July and my supervisor joked that capacitor inventories are also running low, so we’ll be designing boards with just resistors soon.
ngl, been kinda freerolling mentally for a couple of months, not really feeling anything and kinda just “existing” overall. Started jogging actively couple months ago, as I was starting to feel a bit… house cramped. Just needed something developmental to do.
I was approached by the old company about possible freelance work, designing a BMS for a customer case, so I’ll have to see if it comes up at some point, if they get the case.
Finally starting to feel like doing some kind of electronics project again, been looking at sourcing over couple months though and just noted that some of the more cool and interesting ICs are of course out-of-stock. I have some backlog on the FlexiBMS firmware development side as well that I feel like starting to look back into.
Rest of the year is likely to be kinda quiet.
23 Likes
I got lucky a couple of weeks back and discovered a few FlexiBMSs left in stock at a local store, they’re now sold out, but I picked up the second last one they had. Plugged it up to the USB and the serial port comms check out ok, will likely wire it up to the battery this weekend for the real test. Such a great form factor and feature set for a BMS, before finding this I was very nearly going for an external BMS type solution. Thanks for all the work you’ve put in, so sorry about the current situation.
Drew up a quick case for it. The ones found needed some modifications to support a horizontal USB mount, and I wanted to support running wires out the side.
Tempted to play round with the firmware to wire up an I2C OLED display, but honestly just a little scared of ending up with a brick. Workaround could be to drive the display via an arduino + CAN module, and it’s quite the workaround but means I get to leave the FlexiBMS as is.
Reckon there’s a good market for a similarly sized ‘dumb’ BMS. I’ve honestly no idea if this is feasible under ideal conditions, let alone with the current chip shortage.
11 Likes
Setbacks can happen and are very normal, sucks some things are out of hand. I hope you realize you did some awesome work. Somtimes you get caught up in life and you dont actually realize what you have already achieved when you look back. I mean you’ve developed a complete product and making your own manufacturing setup was nuts, also all the processes you had to setup, so impressive that you pulled that off. Hope you get some new and fun opportunities. We are rooting for you!
8 Likes
So I repurposed @NuRxG’s Balance Buddy to read and display FlexiBMS data via CAN. You can grab the code from here. Not sure what/if I’ll use this for; I’m working on a OneWheel kind of thing so wanted to get a little more familiar with the Balance Buddy code.
It’s rough at the moment and will only display individual cell voltages and overall pack voltage. There’s more info sitting there, but there’s only so much you can fit on a 1in display.
Is there some way I can power this from the FlexiBMS itself? A 5v that is only enabled when a charger is connected would be great.
7 Likes