bluetooth BMS?

Batteries, Chargers, and Battery Management Systems.
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thundercamel   1 kW

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Re: bluetooth BMS?

Post by thundercamel » Nov 14 2019 9:08am

Basically the whole time, my meter showed that group 11's voltage was 4.165. I turned off the balancing right after that screenshot, since it was balancing 11 sometimes when it should have been balancing everything but 11, and the voltage reading went right back to 4.165.
My Ebike builds - Existing bikes, affordable motor kits, self built 14s6p batteries - Now with more recumbent!

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Okami   10 W

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Re: bluetooth BMS?

Post by Okami » Nov 16 2019 2:00pm

Hi, newbie to bluetooth bms and still havent read whole discussion, but:

Has anyone come up with a way to increase range for the bluetooth?

I tried to mount this bluetooth on multi rotor drone, to properly see voltage levels, but the 'reception' is so bad, that the connection gets broken apart after like 5-6meters..

Has anyone else tested the bluetooth range for these bms'es? The model which im having seems to have really bad range or something is really interfering..

Was hoping for at least 10 meters of range or so..

Not sure whenever to look for other options (to remotely view cell levels) or just find a way how to improve the signal or change to 2.4ghz communication..

This is to see the cells dont go out of whack while in flight and also properly monitor temperature and voltage drop at various loads.

larsb   100 kW

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Re: bluetooth BMS?

Post by larsb » Nov 16 2019 3:14pm

larsb wrote:
Nov 03 2019 12:27pm
My 300A smart BMS bought from ICGOGOGO has started to fault, reason is that cell1 is seemingly dropping to nearly zero volt. It’s on and off at random. Anyone else got the same issues? I’d guess a poor connection would be less digital (and go to zero) so i suspect it is unfixable.
Closing the loop on this one:
I found the problem, one of the balancing wires had started to slide out of the connector shell. They are not the best quality.. still good news as the smart bms is up and running again.
Ride on!

john61ct   100 MW

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Re: bluetooth BMS?

Post by john61ct » Nov 16 2019 3:47pm

Okami wrote:This is to see the cells dont go out of whack while in flight
No need to watch BMS while flying, most do without completely.

Telemetry for pack level only, just be sure balanced before flying.


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flippy   1 MW

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Re: bluetooth BMS?

Post by flippy » Nov 17 2019 7:48am

larsb wrote:
Nov 16 2019 3:14pm
larsb wrote:
Nov 03 2019 12:27pm
My 300A smart BMS bought from ICGOGOGO has started to fault, reason is that cell1 is seemingly dropping to nearly zero volt. It’s on and off at random. Anyone else got the same issues? I’d guess a poor connection would be less digital (and go to zero) so i suspect it is unfixable.
Closing the loop on this one:
I found the problem, one of the balancing wires had started to slide out of the connector shell. They are not the best quality.. still good news as the smart bms is up and running again.
flippy wrote:
Nov 03 2019 1:41pm
first i would start checking connections, also on the board. might be a dodgy connection on the board as well.

told you. i usually put some hot snot on the wires and connectors to prevent them fom moving.
Lithium beats liquid dinosaurs.

larsb   100 kW

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Re: bluetooth BMS?

Post by larsb » Nov 17 2019 7:57am

I put liquid tape on the other connector already before as several wires wanted to slide out on that one. Should have followed the logic :mrgreen:
Ride on!

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thundercamel   1 kW

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Re: bluetooth BMS?

Post by thundercamel » Nov 18 2019 9:24am

Okami wrote:
Nov 16 2019 2:00pm
Hi, newbie to bluetooth bms and still havent read whole discussion, but:

Has anyone come up with a way to increase range for the bluetooth?

I tried to mount this bluetooth on multi rotor drone, to properly see voltage levels, but the 'reception' is so bad, that the connection gets broken apart after like 5-6meters..

Has anyone else tested the bluetooth range for these bms'es? The model which im having seems to have really bad range or something is really interfering..

Was hoping for at least 10 meters of range or so..

Not sure whenever to look for other options (to remotely view cell levels) or just find a way how to improve the signal or change to 2.4ghz communication..

This is to see the cells dont go out of whack while in flight and also properly monitor temperature and voltage drop at various loads.
Lol, every bluetooth device I've ever used has been short range, which is all it was designed to be. I feel lucky whenever my BMS connects from the garage to my living room.
My Ebike builds - Existing bikes, affordable motor kits, self built 14s6p batteries - Now with more recumbent!

wjr   10 W

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Re: bluetooth BMS?

Post by wjr » Nov 22 2019 8:42pm

eee291 wrote:
Feb 14 2019 7:37am
I've had about a 50% failure rate with the PC programmer boxes, so I would suggest buying one or two additional ones.
You can get them separately on Aliexpress just in case:
https://www.aliexpress.com/item/7S-24V- ... 3c001Q0iSG
This link is outdatet: "Sorry, this item is no longer available!"

Searching for a replacement, I found this ad on IC GOGOGO store
https://www.aliexpress.com/item/33049139356.html
which has an "UART Box" - is this what I need?

I have this BMS:
https://www.aliexpress.com/item/32856349172.html
ANT Smart BMS 10s to 24s 300A w/ display

And where can I attach the serial box?
Do I have to pull the bluetooth module off?
Or can I use the display port, which looks like a serial connection as well?

I will try to get away without the PC software, but regarding the delivery time, I prefer to have the programmer box handy in case I need it.

wjr   10 W

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Re: bluetooth BMS?

Post by wjr » Nov 23 2019 1:05pm

hm. looks like they have changed the board.
I has printed on silk

Code: Select all

RV24.1.4
ANT-BMS-24S
WWW.MAYIBMS.COM
The BT module is soldered to the board,so I don' want to unsolder this to connect a serial adaptor.
Can I connect a PC software at all?
Do I need one, at all?

I don't see any other serial port than the one to the display on the main board.
There is another serial connector unpopulated on the display, and a CAN as well,
But I don't hink that I want connect my PC to the display, do I?

anyway, the display board is labelled RV4.8 in silk, and "LCD/LED5VQ" on a paper sticker attached
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wjr   10 W

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Re: bluetooth BMS?

Post by wjr » Nov 23 2019 1:14pm

looked up mayibms.com, but can't get very far there.
May be someone capable of Chinese language could go farther.
They have an "EN" button, but that seems just to translate the menu, not the content.

Their images still seem to display the old versions of the BMS.
So I don't see what all those unused connectors on my "new version" board might be useful for.

artvk   10 mW

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Re: bluetooth BMS?

Post by artvk » Nov 24 2019 11:09pm

I just bought this BMS https://www.aliexpress.com/item/3284077 ... 4c4dWHUaFR

After connected all balance wire and connected to pc, the software in PC show wrong data in new Samsung 25R cell 1 (0.5V) and cell 2 (1.6V)
I already measure from the cell balance wire with multimeter and the data is same as other 3.5V.
also the cell 1 and 2 voltage even show less in Mobile version than in PC's.


Do I have to setup some parameter ? I order Li-on 20S version
Have anyone got it issue ?
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eee291   100 kW

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Re: bluetooth BMS?

Post by eee291 » Nov 25 2019 2:49am

You have to connect the B- on the BMS as well, only the balance wires is not enough.

artvk   10 mW

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Re: bluetooth BMS?

Post by artvk » Nov 25 2019 3:45am

eee291 wrote:
Nov 25 2019 2:49am
You have to connect the B- on the BMS as well, only the balance wires is not enough.
Thanks a lot eee291. It works perfect right now.
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artvk   10 mW

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Re: bluetooth BMS?

Post by artvk » Nov 26 2019 10:09pm

JBD BMS
I have question when unplugged charger and leave it isolated without connected to other components around 12 hours , the total pack voltage bleeding is 0.11 V (from 81.68V to 81.57V)
Is this normal for this BMS ?
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krlenjuska   10 W

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Re: bluetooth BMS?

Post by krlenjuska » Nov 29 2019 2:31pm

I have 1 question about JBD bluetooth BMS.
Is android app enough for settings like charging voltage, balance start voltage and discharge cutoff voltage? I want to charge my pack to 4.10V. I dont wanna buy UART module if i dont need it.

Thanks!

zipoman   100 µW

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Re: bluetooth BMS?

Post by zipoman » Nov 30 2019 4:42pm

Yes, it is possible change settings only with app. But i cant set max voltage 3,5V for LFP, min 3.65V - I must set this voltage by pc. For li-ion I think no problem with 4.1V max voltage, problem is low value.
Last edited by zipoman on Nov 30 2019 4:51pm, edited 1 time in total.

zipoman   100 µW

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Re: bluetooth BMS?

Post by zipoman » Nov 30 2019 4:46pm

artvk wrote:
Nov 26 2019 10:09pm
JBD BMS
I have question when unplugged charger and leave it isolated without connected to other components around 12 hours , the total pack voltage bleeding is 0.11 V (from 81.68V to 81.57V)
Is this normal for this BMS ?
0.11 V it is normal voltage drop after unplug charger. When i charge li-ion to 4,2V , after 1hour voltage drop to 4,18V

krlenjuska   10 W

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Re: bluetooth BMS?

Post by krlenjuska » Dec 01 2019 6:08pm

zipoman wrote:
Nov 30 2019 4:42pm
Yes, it is possible change settings only with app. But i cant set max voltage 3,5V for LFP, min 3.65V - I must set this voltage by pc. For li-ion I think no problem with 4.1V max voltage, problem is low value.
Thanks i ordered 6S-10S version.

tolkaNo   100 W

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Re: bluetooth BMS?

Post by tolkaNo » Dec 06 2019 9:17pm

How long does the bluetooth module last on these things? Mine seems to have killed itself after about 6 months

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tmho   100 W

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Re: bluetooth BMS?

Post by tmho » Dec 10 2019 2:22am

tmho wrote:
Jun 23 2019 3:35am
I finally finished my battery pack with the bluetooth BMS. But something strange that I cannot understand why.

I set the no. of cell (14s) and the capacity (13.5AH) of the pack. And I got the following readings from the app.

Voltage of the pack: 51.7V
Capacity of the pack: 7.006AH (52%)
Highest voltage of the cells: 3.691V
Lowest voltage of the cells: 3.688V

Then I started to charge the pack. I saw the voltage and capacity went up gradually and that was normal. After charging for about half an hour, I stopped the charging by unplugging the charger. And I got the following readings from the app which I think should also be normal. (Sorry, I did not take a screenshot)

Voltage of the pack: 55.1V
Capacity of the pack: 9.091AH (68%)

But after that, I found the capacity reading still going up. At about 40 minutes after unplugging the charger, I got the following readings.

Voltage of the pack: 54.1V
Capacity of the pack: 9.530AH (71%)
Highest voltage of the cells: 3.860V
Lowest voltage of the cells: 3.858V
Screenshot_2019-06-23-00-55-19.png


Why the capacity of the pack continue to increase after the charging had stopped? Is something wrong with the app?

PS: so far after the above screenshot, the capacity reading stays at 9.530Ah without going further up.
Further to my post above dated June 21, 2019, on September 21, 2019, I got the following readings.
Voltage of the pack: 50.2V
Capacity of the pack: 6.230AH (47%)
Highest voltage of the cells: 3.590V
Lowest voltage of the cells: 3.588V
Screenshot_2019-09-21-10-17-13.png
Screenshot_2019-09-21-10-17-13.png (111.27 KiB) Viewed 1940 times
After that, I have not used the battery (no charging and no discharging). Today, I have the following readings.
Voltage of the pack: 48.3V
Capacity of the pack: 0.836AH (7%)
Highest voltage of the cells: 3.452V
Lowest voltage of the cells: 3.450V
Screenshot_2019-12-09-16-06-50.png
Screenshot_2019-12-09-16-06-50.png (109.18 KiB) Viewed 1940 times
This time, it seems that the capacity should not decrease by that much even though the BMS may still draws some current during this storage period. Am I correct? Is there something wrong with the app or I did not set the parameters properly?

P.s. My battery is 14S4P. I set the no. of batteries to 14s and the battery physical capacity to 13.5AH. I have reset to factory settings and set 14s and 13.5AH again, but still got the above readings.

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tmho   100 W

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Re: bluetooth BMS?

Post by tmho » Dec 10 2019 6:33am

Also, I have downloaded the app for iphone hoping that it will be normal. But after opening the app, it just keeping scanning and cannot connect to the battery. Could somebody help me on this please?

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eee291   100 kW

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Re: bluetooth BMS?

Post by eee291 » Dec 10 2019 3:29pm

Hey guys, I thought I'd make an announcement about the updated JBD App and PC programming software.
I know a few guys who don't update and then get issues with the newer Android versions and what not.

Here are the links:
Link to the App and PC soft.
http://www.jiabaida.com/home-1.7-info-i ... Id-52.html
Direct link to the Zip file.
http://www.jiabaida.com/uploads/soft/xiaoxiangBMS.zip

Some pics:
https://imgur.com/a/lWp3iOA

When trying to connect to your BMS, the App will ask you to make a 6 digit password (there is no confirmation so be careful!)
It looks like you can change a lot more settings than before, looks like most people won't be needing the wonky PC dongle :thumb:

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tmho   100 W

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Re: bluetooth BMS?

Post by tmho » Dec 10 2019 3:56pm

tmho wrote:
Dec 10 2019 2:22am
tmho wrote:
Jun 23 2019 3:35am
I finally finished my battery pack with the bluetooth BMS. But something strange that I cannot understand why.

I set the no. of cell (14s) and the capacity (13.5AH) of the pack. And I got the following readings from the app.

Voltage of the pack: 51.7V
Capacity of the pack: 7.006AH (52%)
Highest voltage of the cells: 3.691V
Lowest voltage of the cells: 3.688V

Then I started to charge the pack. I saw the voltage and capacity went up gradually and that was normal. After charging for about half an hour, I stopped the charging by unplugging the charger. And I got the following readings from the app which I think should also be normal. (Sorry, I did not take a screenshot)

Voltage of the pack: 55.1V
Capacity of the pack: 9.091AH (68%)

But after that, I found the capacity reading still going up. At about 40 minutes after unplugging the charger, I got the following readings.

Voltage of the pack: 54.1V
Capacity of the pack: 9.530AH (71%)
Highest voltage of the cells: 3.860V
Lowest voltage of the cells: 3.858V
Screenshot_2019-06-23-00-55-19.png


Why the capacity of the pack continue to increase after the charging had stopped? Is something wrong with the app?

PS: so far after the above screenshot, the capacity reading stays at 9.530Ah without going further up.
Further to my post above dated June 21, 2019, on September 21, 2019, I got the following readings.
Voltage of the pack: 50.2V
Capacity of the pack: 6.230AH (47%)
Highest voltage of the cells: 3.590V
Lowest voltage of the cells: 3.588V
Screenshot_2019-09-21-10-17-13.png

After that, I have not used the battery (no charging and no discharging). Today, I have the following readings.
Voltage of the pack: 48.3V
Capacity of the pack: 0.836AH (7%)
Highest voltage of the cells: 3.452V
Lowest voltage of the cells: 3.450V
Screenshot_2019-12-09-16-06-50.png

This time, it seems that the capacity should not decrease by that much even though the BMS may still draws some current during this storage period. Am I correct? Is there something wrong with the app or I did not set the parameters properly?

P.s. My battery is 14S4P. I set the no. of batteries to 14s and the battery physical capacity to 13.5AH. I have reset to factory settings and set 14s and 13.5AH again, but still got the above readings.
I just found out why I got such readings. They calculate the capacity (or state of charge) based on the voltage of the cells. From the latest version of the app, I can see that they set 3.405V as 0% and 3.477V as 10%. Therefore, my cells at 3.45V will be treated as 7% (7% of 13.5AH is 0.945AH). I understand such method (state of charge based on the voltage) is not that accurate. However, if somebody know the most appropriate voltages for various state of charge (for lithium ion cells), please let me know so that I can change the settings in the app.

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Re: bluetooth BMS?

Post by john61ct » Dec 10 2019 4:25pm


tmho wrote:I just found out why I got such readings. They calculate the capacity (or state of charge) based on the voltage of the cells.
There are three factors there, which are only loosely if not barely related to each other.

SoC, at least between 100% and 0%, is only very roughly related to voltage, and even then only after isolated and resting for some time.

Capacity, aka State of Health, can only be determined accurately through precisely timed discharge tests with a CC load. Roughly with an Ah / coulomb counter, but need to cycle completely from standard 100% Full to 0% empty SoC benchmark points.

Getting the actual SoC very precisely can be done using similar tests once the Ah capacity has been determined.

I do not know of any BMS I would trust for any of these.

Other than voltage of course, but that accuracy needs to be verified, calibrated against separate known good instrumentation as well.


SilverLine   100 W

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Re: bluetooth BMS?

Post by SilverLine » Dec 11 2019 5:23pm

Hallo

If i buy the cheapest model, the one with lowest Amp rating (like the JBD 20s 30a), and only use the BMS for charging, and bypassing discharged. Will I still have most of the cool features, like cell monitoring via app, cell ballancering, and manuel ballancing if a cell drift ?
Thanks

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