bluetooth BMS?

flippy said:

tmho said:

I would also like to buy one for my new battery pack project.
Can the Bluetooth app show all the information that LCD display shows? If yes, then I would just use my cellphone as display. If no, what information will not be shown on the app?

Click to expand...

battery percentage.

but it's useless anyway. it's off by miles.

Click to expand...

Hi flippy, thanks for your reply. Most probably I will not need the LCD display. Actually, I think they should include the battery percentage function in the Bluetooth app. It should not be that difficult for them to do so.

Alright, making slow progress.
Wired up the battery with the voltage leads to the BMS. Photo below to prove it! Haha
Need to get some thicker wire and connectors to finish it.
So, might as well work on the bluetooth app while I wait. Went to google play store to type in the names of the bluetooth apps I saw here and Nada.
Seller sent me something called vbms English.apk
I have a feeling that's my Bluetooth app.
Wont save to my phone when I try to save it it?
Is there an a bluetooth app in the play store that will work with my bms pictured above?
If not, could someone guide me on the process of getting the the proper app for my BMS installed on my android phone?

For those coming after me on this journey who are on Android:
The file that I received which contains the Bluetooth BMS app is an .apk file extension file. I could not find the program as an app on google play at this time but maybe in the future there will be an approved app that that is compatible.
Before you do anything else you will have to go to your phone security settings and allow installation from unknown sources. On my phone default setting was to not allow which makes sense.
Once installation from unknown sources is allowed, you can now try to download and open your bluetooth BMS .apk file.
In my case, I was sent the actual BMS.apk file to my email as an attachment. Think of this .apk file as an app but just not an app approved on the google play store. This attachment was sent to my yahoo email account as I requested.
The file appeared complete but the .apk file would not save, view or open from my yahoo email as an attachment to my android note phone. So no go.
I read online that gmail has a good understanding of how to handle .apk files. So, I simply sent the entire yahoo email with the BMS.apk file attachment to my gmail email address.
Then I went to my gmail and opened that new email with the same BMS.apk attachment.
Attachment was there and so I went to open it.....
working, working.
Wala, gmail allowed the download and opened the BMS app for me. Its like magic!
Have the app on my phone now.
Learning alot more than I expected to from this battery build.

Hi there

I ordered the 300 amps version from icgogogo, 3 units

All 3 BMS are now functionning, in bluetooth everything is OK but none of the 3 screens will boot. With a friend who succesfully installed a screen on his own 24s (exactly the same BMS, coming from this shop) we followed very carefully the docs and videos and do not understand why the screens won't boot.

Did we miss something ? It seems unlikely that 3 screens would be malfunctioning at the same time.

Thanks in advance for your help, forum !

They need their own power, its on the other side of the board.

It's fed, as I see a red light appear when I plug the screen power cable and long push the screen start button. But this led shuts off as soon as I don't push the screen start button.

Screen just does not boot...

csc said:

It's fed, as I see a red light appear when I plug the screen power cable and long push the screen start button. But this led shuts off as soon as I don't push the screen start button.

Screen just does not boot...

Click to expand...

It works on all 4 of my BMS. The LCD needs power. Connect it across batt+ to batt -. It also measures total pack voltage via it's power wires.

Assuming the BMS is turned on, then the LCD should display data. I'd make sure you don't have settings in the BMS that disable it. Maybe that's the problem?

I was thinking about these BMS and their concept of "capacity" and "state of charge". I think the implementation is very poor. For example, the JBDTools and the protocol ( https://drive.google.com/file/d/0B3UXptx89r4NZ3VLTHlVS1ZGTTQ/view ) show state of charge in Ah, taking into account an user set capacity and extrapolating to a voltage curve (which you can set 6 points: CellFullVoltage, CellEndVoltage, 80%Capacity,60%Capacity,40%Capacity,20%Capacity). Of course, the electric charges returned value can be totally fake. The proper state of charge to return only can be a ratio, percentage, etc.

So, I was thinking if using the protocol and an attached arduino, we can read the pack voltage and amperage in very frequent intervals and calculate the real charges that are being output by the BMS. I mean, to make something like this https://www.amazon.com/10-100V-Battery-Universal-Accurate-Coulometer/dp/B06Y3KZ56H/ref=sr_1_fkmr0_1?ie=UTF8&qid=1536264572&sr=8-1-fkmr0&keywords=drok+coulometer without needing another shunt in the circuit.

What do you think?

As a side note, on my boards, the voltage readings seem very good, but the amperage is way off. Using a multimeter and a lab power supply I got the real values and re-calibrated the BMS. Mine by default was around 20% off on each direction (charge and discharge)

Also, the temperature sensors are all reading different values, so it is good to re-calibrate them using an ambient thermometer and setting all to the same value.

Next challenge.
Went to extend the factory presoldered wire coming off the BMS so I could have 2 seperate longer negative leads coming off the C- pad. One for charge and one for discharge as shown for the single C- pad method (in other words both charge/discharge leads connected to the C- pad only).
How are u guys connecting the wires?
Is this black colored wire that came from the manufacturer presoldered to the C- pad aluminum wire?
If yes, then my 10 gauge wire that I have for this is copper and I didnt think you were supposed to connect/solder aluminum and copper wires together? See picture below.
If I cant join these 2 different wire types, then who sells the similar 10 guage wire in aluminum that I need? The place I went to for wire only has copper.

I don't think that's Alu, it's usually pretinned. Looks like the silicon wire I can buy from hobbyking. But you can easily desolder the wire from the BMS and just use your Copper wire. Joining two wires like that is just sketchy as hell.

take a cutter, cut off the wire as close to the board as you can, then desolder what is left and solder the wire directly onto the board.
might want to disassemble the board to get better access.
if you can solder directly on the copper bus bars.
one one side there is a bump on the bus bars, do NOT solder on that as that piece is the shunt that measures the current. never solder on or near those bumps on the bus bars.

the wire is alu, not copper.

also: place the metal plates pack on. it is the cooling surface for the balance wires and mosfets. its needs to be there.

Hi, hope someone can help!

I got a 20S Bluetooth BMS from https://www.lithiumbatterypcb.com

I built a 20S4P pack with New LG cells, but i cant get it to work, goes into "IC" status. Front end error. I have checked the wiring, and its correct, anyone know what the problem can be?

Regards

trazor said:

I was thinking about these BMS and their concept of "capacity" and "state of charge". I think the implementation is very poor. For example, the JBDTools and the protocol ( https://drive.google.com/file/d/0B3UXptx89r4NZ3VLTHlVS1ZGTTQ/view ) show state of charge in Ah, taking into account an user set capacity and extrapolating to a voltage curve (which you can set 6 points: CellFullVoltage, CellEndVoltage, 80%Capacity,60%Capacity,40%Capacity,20%Capacity). Of course, the electric charges returned value can be totally fake. The proper state of charge to return only can be a ratio, percentage, etc.

So, I was thinking if using the protocol and an attached arduino, we can read the pack voltage and amperage in very frequent intervals and calculate the real charges that are being output by the BMS. I mean, to make something like this https://www.amazon.com/10-100V-Battery-Universal-Accurate-Coulometer/dp/B06Y3KZ56H/ref=sr_1_fkmr0_1?ie=UTF8&qid=1536264572&sr=8-1-fkmr0&keywords=drok+coulometer without needing another shunt in the circuit.

What do you think?

As a side note, on my boards, the voltage readings seem very good, but the amperage is way off. Using a multimeter and a lab power supply I got the real values and re-calibrated the BMS. Mine by default was around 20% off on each direction (charge and discharge)

Also, the temperature sensors are all reading different values, so it is good to re-calibrate them using an ambient thermometer and setting all to the same value.

Click to expand...

The shunt value is settable in the BMS. More than likely the default value in the BMS's is a generic value that may or may not be right. I've ran into this too. Of course I'm modding all my BMS, but never the less, a micro ohm meter will get you close to the right resistance for the shunts. Dropping in a shunt based watt meter temporarily so you have a comparative value will let you see which way to adjust the shunt on the BMS to get it dead on.

I have several watt meters, but I've found them cheaper on ebay...lots cheaper! You should pay something like $24 for that meter.

Personally, just get the shunt values set right in the BMS and keep your set up simple as possible. Yes an arduino could do lots of interesting things for you, but why bother? If you really need accuracy, then get a dedicated watt meter. There's ones like this that are super capable and don't use a shunt at all. I have one of these (second item)...it's a nice meter.

https://www.ebay.com/itm/New-Hall-Coulomb-Meter-DC-Voltage-Current-Capacity-Panel-Meter-0-90V-0-500A/253813718353?hash=item3b1879fd51%3Am%3AmQgPet-ap01Jqkm6LdaepIQ&var=553099226338

https://www.ebay.com/itm/Wireless-Hall-Coulomb-Meter-DC-Voltage-Current-Capacity-Panel-Meter-120V-0-500A/253813096530?hash=item3b18708052%3Am%3Am5fhBRiTezVB6oYo2R-0MIA&var=553098630896

Temp sensors...lol...I have real name brand sensors I bought from Mouser. Take any 5 of them, lay them side by side and measure the resistance of each sensor. I call it good if they are producing close to similar resistances. Chinese sensors...like on these BMS...well they are probably not any better. The Atmel 328 ADC's have 10 bits of resolution. Don't expect really good "accuracy". Never mind that the sensors can't be calibrated.

Mikebike said:

Next challenge.
Went to extend the factory presoldered wire coming off the BMS so I could have 2 seperate longer negative leads coming off the C- pad. One for charge and one for discharge as shown for the single C- pad method (in other words both charge/discharge leads connected to the C- pad only).
How are u guys connecting the wires?
Is this black colored wire that came from the manufacturer presoldered to the C- pad aluminum wire?
If yes, then my 10 gauge wire that I have for this is copper and I didnt think you were supposed to connect/solder aluminum and copper wires together? See picture below.
If I cant join these 2 different wire types, then who sells the similar 10 guage wire in aluminum that I need? The place I went to for wire only has copper.
Wire dilema.jpg

Click to expand...

Just don't do that!

C- is for Charging and P- is for Power. Terminate that short wire in a 5.5mm bullet. Connect a longer wire to it via another 5.5mm bullet. If you used a male on the BMS side of C-, then your longer wire has a female bullet on it. Power your EV from P-, NOT C-. I solder bullet connectors direct to the BMS solder pads and then connect wires via those bullets. It makes the whole thing removable if needed. It happens...not often...but it happens that a BMS flakes out and shuts down for no reason. Being able to totally unplug it, gets it going again. I've had this happen a couple of times, but it was a long time ago. Regardless, soldering bullets instead of wires to the solder pads makes the BMS by-passable or removable and doesn't effect performance or reliability.

Ultraclearance said:

Hi, hope someone can help!

I got a 20S Bluetooth BMS from https://www.lithiumbatterypcb.com

I built a 20S4P pack with New LG cells, but i cant get it to work, goes into "IC" status. Front end error. I have checked the wiring, and its correct, anyone know what the problem can be?

Regards

Click to expand...

More than likely, IF you really do have it all wired correctly, then you have a setting wrong. Also, in the PC app you can make changes you can't do in the android app. Make sure everything is set correctly. I'm not accusing you of anything, but I have yet to have one of these BMS NOT work right out of the box. Of course before I ever connect my pack to the BMS, I've tested my balance cable multiple times to be dead sure I wired it correctly. Mistakes are easy to make. 2 crossed wires will cause all sorts of weird behavior.

Thought about this some more...

Pin 0 in the balance connector on the BMS is connected to BATT- be sure this is connected correctly on your pack. B- on the BMS is ALSO connected to BATT-. The BMS won't work right without BOTH of these connections correct. I vaguely remember not having B- connected and getting this error some time back.

Thanks for the suggestions.
Almost home. Battery pack complete except for the outside heat shrink. Made some acrylic ends for it to keep it all bolted together. Want to use clear shrink if I can find it cause I think it would be cool to see the battery.
Everthing seems to be working so far including the VBMS app that was provided. Bluetooth connects and charging also seems to work.
Does anyone have the latest version of the VBMS app? The version I have seems to be an older one and is missing some features I would like to have. Is there a way to upload the lastest .apk versions of these bluetooth apps somewhere so the latest versions can be downloaded by anyone?
There are at least 4 different bluetooth apps (.apk) I am aware of:
MaYi, VBMS, Huayurui, Xiaoxiang
Prolly spelled some of those wrong.
If anyone needs a link I will put (.apk) on google drive and enable share if that method will work to share (.apk) files?

Ok, so, no one has a manual?

And very nice build reference post above using Batteryblocs. I’ve a box of those awaiting the next build.

There is a VBMS, built by a Youtuber https://www.youtube.com/watch?v=08-sI3OGizM&app=desktop a link to the app is within description.

Further research on the VBMS app finally got me to a google play app in the play store.
Previously, I searched the google play store and nothing came up? But there is an app on google play called VBMS.
I purchased it for what I call my Ant 8s to 24s Bluetooth BMS. There are pictures above in my previous posts for anyone interested.
The great news is that the google play store VBMS app is the updated English version app!!
It works perfectly on my Samsung note phone with my ant BMS.
Only cost 6.99US. For all the trouble I've had getting this working properly, the app was well worth it.

What does vbms do? I tried it, but don't see a way to connect.

Mikebike said:

Thanks for the suggestions.
Almost home. Battery pack complete except for the outside heat shrink. Made some acrylic ends for it to keep it all bolted together. Want to use clear shrink if I can find it cause I think it would be cool to see the battery.
Everthing seems to be working so far including the VBMS app that was provided. Bluetooth connects and charging also seems to work.
Does anyone have the latest version of the VBMS app? The version I have seems to be an older one and is missing some features I would like to have. Is there a way to upload the lastest .apk versions of these bluetooth apps somewhere so the latest versions can be downloaded by anyone?
There are at least 4 different bluetooth apps (.apk) I am aware of:
MaYi, VBMS, Huayurui, Xiaoxiang
Prolly spelled some of those wrong.
If anyone needs a link I will put (.apk) on google drive and enable share if that method will work to share (.apk) files?

ANT BMS and battery.jpg

Click to expand...

please put the metal plate back on. the balance board need this for cooling. that is what the thermal band is for.

please put the APK up so we can see if it is a newer version.

The VBMS does all voltage set point adjustments, alarms, controls and more to manage your battery.
Look up VBMS on the google play store. There is an overview there. Looks like it also coordinates with gps, etc. but I havnt got into that part.
Thanks for pointing out the importance of putting the aluminum cover back on. Did that before heat shrinking everything tight.
First real battery build and I am happy with it. Actually fits into my new bag I bought for it! Working on making my cargo bike look like a vintage military bike.

Doesn't work for me. How does it pair or connect?

Turn on the BMS by holding the small momentary micro switch down (if you have connected it) or shorting the two small switch wires to each other for 3 seconds then disconnect them. This turns on the BMS. Make sure both red led lights are turned on to show the BMS is working and the Bluetooth module is on. If you don't see the red lights on the BMS you either have a defective unit or you don't have enough voltage going to the + to power up the BMS. If I recall correctly you need at least 18V to power the BMS through the sense wire connection.
Turn on your bluetooth on your phone on so it can see the bluetooth BMS in your Bluetooth settings. You have to go to your bluetooth settings in your phone and should see the bluetooth BMS as something it is possible to pair to with your phone. Then pair the BMS with your phone.
The Code is 1234 to pair the phone and this bluetooth BMS.
Once the pairing is successful you should then see the BMS as paired device on your phone. If it is not a paired device the phone and the BMS cant talk to one another.
Then you open the VBMS app.
The VBMS app connects and shows all battery information automatically for me once the BMS and the phone are paired. If it is not connecting then you press the connect button on the VBMS app and it should connect and then show you the battery info.
My setup: Ant 8s to 24s Bluetooth BMS, Samsung note phone, VBMS app from google play store. VBMS connects automatically and works no issues once paired for me.

In my case there was no attempt to connect, and no connect button.
Unlike previous version that I use.
Can you get a screen shot?

Got a new rca tablet. Still can't connect bms or vbms.
I did get HYD to connect. I like that better in any case.
The Chinese version always connects, but has other issues.