bluetooth BMS?

[Dui ni shuo de dui]

Reading the posts from a few months back, looks like it's usable except the lousy english app.
Concerning reliability, so far how many miles have you guys road tested this bms?
What's the max # of cells it can display on the lcd screen? I only see 18 on the seller page.
Does the "Automatic balance" function really work?

So far I made a little less than 1000 km with it, no problem.

The max number of cells per screen is about 18, but if you press the button you'll be able to see the next page of cells. The screen is unfortunately only able to display 18 cells at once, but it doesn't really matter since the other screens will tell you the highest and lowest cells voltages as well as the average. And if you absolutely need to see all the cells in the same screen for whatever reason, you can do that in the bluetooth app.

Yes, the automatic balance function works well. You need to fully charge first, then disconnect the charger and enable it (I'm not sure this process is actually mandatory but this is the manufacturer's recommendation anyway). You can set up the balancing precision, in my case it is 0.002V.

 

[flippy]

Note that voltage measurment is usually a bit off under 3.6V. I recommend starting balancing only above 3.7 or higher.

 

[rio9210]

I have this smart BMS

https://www.greenbikekit.com/smart-programmable-lithium-bms-with-software-modification.html

does anybody manage to find max amperage available on bluetooth/pc module port? I'm trying to feed a GPS tracker from the smart BMS with those mini DC step-down modules and I don't want to burn BMS due to too much Ampere absorption on that 12V line.

I don't have much space inside the battery so those bulky 10-60V step-down DC modules are out of question (yes, I don't have 5x2x2 cm of space inside my battery).

 

[Scott S]

Ok. I am ready to build a 14s 28ah pack. I am interested in the 60 amp bms from bms battery or I can get it from senchan direct.
Also do I really need the PC interface for settings or can the Android app cover most as I want to charge to 4.0 or 4.1 volts per cell but that is also charger related and if I buy from bms battery it does not come with PC interface. Only the Bluetooth module

 

[rio9210]

Ok. I am ready to build a 14s 28ah pack. I am interested in the 60 amp bms from bms battery or I can get it from senchan direct.
Also do I really need the PC interface for settings or can the Android app cover most as I want to charge to 4.0 or 4.1 volts per cell but that is also charger related and if I buy from bms battery it does not come with PC interface. Only the Bluetooth module

You need PC interface. Bluetooth one is limited. Only the PC application is full-featured.

 

[ElectricGod]

Ok. I am ready to build a 14s 28ah pack. I am interested in the 60 amp bms from bms battery or I can get it from senchan direct.
Also do I really need the PC interface for settings or can the Android app cover most as I want to charge to 4.0 or 4.1 volts per cell but that is also charger related and if I buy from bms battery it does not come with PC interface. Only the Bluetooth module

BT is great for checking things while riding or when stopped somewhere, but really you want the PC app if you want to access all the settings. From the Android app you can do about 80% of things.

 

[ElectricGod]

I have this smart BMS
does anybody manage to find max amperage available on bluetooth/pc module port? I'm trying to feed a GPS tracker from the smart BMS with those mini DC step-down modules and I don't want to burn BMS due to too much Ampere absorption on that 12V line.

I don't have much space inside the battery so those bulky 10-60V step-down DC modules are out of question (yes, I don't have 5x2x2 cm of space inside my battery).

I don't recommend sapping power from the BMS. Go a different route.

You need 5 volts to charge the GPS battery. The GPS will also run on it's battery for probably several months. Your motor controller delivers 5 volts for the halls, throttle and MCU. They are all powered from the same small DC-DC converter inside the controller. This power supply can usually handle a few hundred more mA of loading. It may be able to provide your charge current needs. I'd test this by running down the GPS battery to 50% and then power up the motor controller with it connected to halls and throttle. Measure the voltage. Now add the GPS to it. Does the voltage drop? If it does, then this won't work. That little DC-DC converter can't deliver the current you need for charging the GPS module.

Another option is a small linear regulator. The TL783 is very small and needs 2 external resistors to set the output voltage. They work at 1.25 to 125 volts in and can regulate that down to whatever you need at 700mA. That ought to get you what you need and still be very small. I've used these regulators several times in EV's and related hardware. They work pretty well.

 

[Scott S]

Ok. I am ready to build a 14s 28ah pack. I am interested in the 60 amp bms from bms battery or I can get it from senchan direct.
Also do I really need the PC interface for settings or can the Android app cover most as I want to charge to 4.0 or 4.1 volts per cell but that is also charger related and if I buy from bms battery it does not come with PC interface. Only the Bluetooth module

You need PC interface. Bluetooth one is limited. Only the PC application is full-featured.

Do you have a recommendation of exactly who to purchase the 14s 60 amp bms from by chance?
Thanks.
Ps where can I download the PC software and maybe a user guide. Anyone know lol

 

[ElectricGod]

Ok. I am ready to build a 14s 28ah pack. I am interested in the 60 amp bms from bms battery or I can get it from senchan direct.
Also do I really need the PC interface for settings or can the Android app cover most as I want to charge to 4.0 or 4.1 volts per cell but that is also charger related and if I buy from bms battery it does not come with PC interface. Only the Bluetooth module

You need PC interface. Bluetooth one is limited. Only the PC application is full-featured.

Do you have a recommendation of exactly who to purchase the 14s 60 amp bms from by chance?
Thanks.
Ps where can I download the PC software and maybe a user guide. Anyone know lol

This...IC GOGOGO is the place to buy from.

https://www.aliexpress.com/store/product/Smart-BMS-15S-48V-56V-Lipo-Lifepo4-Lithium-Battery-Protection-Board-Balance-15-Cells-with-Communication/2856009_32871846681.html?spm=2114.12010612/itm2home-4.8148356.56.5e3d3de21FnvnO

 

[Scott S]

I found the PC software and user guide here. I can purchase the bms here also! Plus it comes with the PC interface also!

https://www.lithiumbatterypcb.com/product-category/smart-bms/

 

[shinyballs]

Thanx guys! I usually start balancing when a cell hits 4V. So, it can balance up to 24s, I don't see any pc connectivity option; I guess it's not supported.

 

[ElectricGod]

This...IC GOGOGO is the place to buy from.

https://www.aliexpress.com/store/product/Smart-BMS-15S-48V-56V-Lipo-Lifepo4-Lithium-Battery-Protection-Board-Balance-15-Cells-with-Communication/2856009_32871846681.html

I have exactly one of this XIOAXING 14S BMS and I noticed in the app there is the function to see the time line of current and voltage of every cell level, tapping on the display of that cells voltage, but tapping the 14th cell the app exits without error message? Anybody know how to pass this info to the developer?

Interesting...all of mine are 16S or 20S. I just connected to a 16S pack and checked all 16 cells...no problems. I could see those graphs for all the cells. I specifically went to cell 14 multiple times...nothing happened incorrectly. I wonder if this is old firmware in your BMS or a problem with your phone. Try removing the app and installing it again? you need the PC app to update the firmware in the BMS.

 

[rio9210]

Found it Scott had posted above, and the new version is Android APP V2.1.1011
Here: https://www.lithiumbatterypcb.com/smart-bms-software-download/
I'll install it tomorrow and report...

No, the latest app is version 2.1.1022, you can download it from GreenBikeKit (has good prices and their stuff works well)

https://www.greenbikekit.com/upload/smart-bms-pcm-connection-diagram-app-software-2018-version-greenbikekit.rar

Tested it for 6 days, works flawlessly. App hooks to BMS bluetooth module in less than 2 seconds, if bluetooth is enabled on your smartphone.

However, their latest PC application (version V1.A-20180511) is less "polished", some little windows with chinese characters still pop-up, and some main windows labels are showing chinese/strange characters. I'm using version "JBDTools-EN V1.1-20160718.exe" which has no chinese "cosmetic glitches".

Latest FT232RL drivers (PC interface for the smart BMS) is version 2.12.28, and it's even WHQL Certified. You can download them here (both 32 and 64 bit), there are Linux and Android drivers, too

http://www.ftdichip.com/Drivers/D2XX.htm

That's all you need for the Xiaxiang/Jia Bai Da smart BMS.

Just bought the right stuff, installed the right software and things (even chinese ones) works... :wink:

P.S. Tried to install QQ International, just to be able to contact the Xiaxiang manufacturer group for some technical details, but never saw an app requesting so many permissions (practically wants to know and access everything on your phone) so I've abandoned that idea.

 

[Scott S]

How much constant drain on the battery is there when using these Bluetooth bms when in storage?
I don't want to kill a 800 dollar plus pack if I don't ride or check the charge status for a few weeks lol

 

[flippy]

The bt goes to sleep (off) when no current flow is detected for a while. You can set this time in the settings. Also the sleep timer of the bms can be set.

In order to wakt it up you need current flow or press the power button for a second.


I would just keep it on a charger set to 3.8v (per cell) and leave it on there if you dont use it for a long time. Or better: put it on a timer for 15 min per day or so.

 

[rio9210]

I have this smart BMS
does anybody manage to find max amperage available on bluetooth/pc module port? I'm trying to feed a GPS tracker from the smart BMS with those mini DC step-down modules and I don't want to burn BMS due to too much Ampere absorption on that 12V line.

I don't have much space inside the battery so those bulky 10-60V step-down DC modules are out of question (yes, I don't have 5x2x2 cm of space inside my battery).

I don't recommend sapping power from the BMS. Go a different route.

You need 5 volts to charge the GPS battery. The GPS will also run on it's battery for probably several months. Your motor controller delivers 5 volts for the halls, throttle and MCU. They are all powered from the same small DC-DC converter inside the controller. This power supply can usually handle a few hundred more mA of loading. It may be able to provide your charge current needs. I'd test this by running down the GPS battery to 50% and then power up the motor controller with it connected to halls and throttle. Measure the voltage. Now add the GPS to it. Does the voltage drop? If it does, then this won't work. That little DC-DC converter can't deliver the current you need for charging the GPS module.

Another option is a small linear regulator. The TL783 is very small and needs 2 external resistors to set the output voltage. They work at 1.25 to 125 volts in and can regulate that down to whatever you need at 700mA. That ought to get you what you need and still be very small. I've used these regulators several times in EV's and related hardware. They work pretty well.

Found it. It's a small LM2576HV based DC-DC step down, works from 5V to 60V

https://www.banggood.com/5V-60V-To-1_25V-30V-LM2576HV-DC-DC-Step-Down-Module-p-1060892.html?cur_warehouse=CN

Sadly only China Warehouse (no EU/US), but... two weeks for 5 euro shipping i's an acceptable time/money compromise.

 

[ElectricGod]

How much constant drain on the battery is there when using these Bluetooth bms when in storage?
I don't want to kill a 800 dollar plus pack if I don't ride or check the charge status for a few weeks lol

I left a 16,000mah 16S pack unattended for 3 months on one of these BMS. Based on how much the pack was run down after that much time, it would take years to rundown the batteries.

 

[ElectricGod]

Found it. It's a small LM2576HV based DC-DC step down, works from 5V to 60V

https://www.banggood.com/5V-60V-To-1_25V-30V-LM2576HV-DC-DC-Step-Down-Module-p-1060892.html?cur_warehouse=CN

Sadly only China Warehouse (no EU/US), but... two weeks for 5 euro shipping i's an acceptable time/money compromise.

Rio, I have several of those...don't trust them beyond 48 volts. I know they are supposedly good to 60 volts, but all of mine burned out at 60 volts. That linear regulator is far simpler and smaller and I know it runs at up to 125 volts.

 

[rio9210]

Found it. It's a small LM2576HV based DC-DC step down, works from 5V to 60V

https://www.banggood.com/5V-60V-To-1_25V-30V-LM2576HV-DC-DC-Step-Down-Module-p-1060892.html?cur_warehouse=CN

Sadly only China Warehouse (no EU/US), but... two weeks for 5 euro shipping i's an acceptable time/money compromise.

Rio, I have several of those...don't trust them beyond 48 volts. I know they are supposedly good to 60 volts, but all of mine burned out at 60 volts. That linear regulator is far simpler and smaller and I know it runs at up to 125 volts.

I'll use them between 30 and 45V, so I'll be safely way under their design and manufacturing limits. The only doubt, how much will they drain the battery.

 

[ElectricGod]

Found it. It's a small LM2576HV based DC-DC step down, works from 5V to 60V

https://www.banggood.com/5V-60V-To-1_25V-30V-LM2576HV-DC-DC-Step-Down-Module-p-1060892.html?cur_warehouse=CN

Sadly only China Warehouse (no EU/US), but... two weeks for 5 euro shipping i's an acceptable time/money compromise.

Rio, I have several of those...don't trust them beyond 48 volts. I know they are supposedly good to 60 volts, but all of mine burned out at 60 volts. That linear regulator is far simpler and smaller and I know it runs at up to 125 volts.

I'll use them between 30 and 45V, so I'll be safely way under their design and manufacturing limits. The only doubt, how much will they drain the battery.

Battery drain=how much current are you pulling +5% at most. I ran multiples in parallel. They are pretty light weight and don't deliver the current they are spec'd for. Set the output voltages to exactly the same and then wire everything together. I had 6 in parallel since I wanted about 10 amps continuous.

 

[mpmoller]

Hi guys. I am considering buying one of these; https://www.aliexpress.com/item/Smart-Display-300A-8-24S-Cells-Lithium-Battery-Protection-Board-Balance-BMS-Coulomb-Meter-Lithium-iron/32827394534.html?spm=2114.search0104.3.1.2fbb636b5l5a9u&ws_ab_test=searchweb0_0,searchweb201602_2_10152_10151_10065_10344_10068_10342_10343_10340_10341_10696_10084_10083_10618_10304_10307_10820_10821_10302_10846_10059_100031_524_10103_10624_10623_10622_10621_10620,searchweb201603_2,ppcSwitch_5&algo_expid=4c898cf7-cdf5-4fae-bf9e-3ad5c2878623-0&algo_pvid=4c898cf7-cdf5-4fae-bf9e-3ad5c2878623&transAbTest=ae803_1&priceBeautifyAB=0

How stable are they? Do you like it?

Can you set the charge amps in the app? I has a Eaton APR48-3G, and would love to keep using it.

BR
Mpmoller

 

[flippy]

charging current and voltages need to be handled by the charger, not the bms. the bms is a PROTECTION device, it only does its job when shit goes OUT of spec.

if you got too much charging current you need to limit it at the charger side, not the battery side. or do you use the brake to keep the speed instead of lifting off the trottle?


ps: your APR48 is a power supply, not a charger. you need additional current control to make that work.

 

[mpmoller]

charging current and voltages need to be handled by the charger, not the bms. the bms is a PROTECTION device, it only does its job when shit goes OUT of spec.

if you got too much charging current you need to limit it at the charger side, not the battery side. or do you use the brake to keep the speed instead of lifting off the trottle?

Well thank you flippy... I guess.
Can you suggest me a charger that can charge a 72v (max 84v) 18ah battery?

 

[ElectricGod]

charging current and voltages need to be handled by the charger, not the bms. the bms is a PROTECTION device, it only does its job when shit goes OUT of spec.

if you got too much charging current you need to limit it at the charger side, not the battery side. or do you use the brake to keep the speed instead of lifting off the trottle?

Well thank you flippy... I guess.
Can you suggest me a charger that can charge a 72v (max 84v) 18ah battery?

I use meanwell PSU's for my chargers. Here's my thread on building chargers.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=90292&p=1316096#p1316096

 

[flippy]

Well thank you flippy... I guess.
Can you suggest me a charger that can charge a 72v (max 84v) 18ah battery?

mean well ELG150-42A and put 2 of them in series set to 42V each. 300W total charging power and it will fill your battery in under 5 hours from dead. and it's totally silent and portable.
if you want more power you can change the 150 to 300 or even 600 i think.