bluetooth BMS?

[JoostR]

I am unsure whether I will use a 13S9P or a 14S8P 18650 pack for my electric (moped) scooter. I have decided to go for the JBD Smart BMS.

I am thinking about ordering a 14S JBD BMS, but I am not sure if it would be possible to change the 14S BMS to 13S afterwards? What I understand is that this should be possible for an ANT BMS. Is this something that is possible for JBD as well?

 

[thundercamel]

The PC app for the JBD boards let you change from 14s to 13s, but I've never tried it. From what I remember reading one of the balance wires (not sure which) becomes unused, and needs to be tied to a balance wire next to it (not sure which again).

 

[JoostR]

Thanks thundercamel! JBD confirmed it is possible. Maybe someone else can elaborate the schematic?

 

[flippy]

Stupidly high precision, total waste of time and excessive wear on components.

And bad for cells to sit at high SoC% that long

Really best to forget top balancing completely, do it at the bottom, or mid point as they are delivered.

you actually would want more then triple digit accuracy on larger batteries, especially with lifepo4 that has a stupid flat discharge curve.

please stop giving advice about how to charge a battery. recommending a mid point balance "because that is how they are deliverd" is litteraly the most ignorant recommendation i have seen to make as of yet.

 

[john61ct]

Actually it is the ideal, especially for large banks.

But of course nothing to do with using a BMS.

I know dozens of packs that have not needed **any** rebalancing **at all**, well past 7-10 years of often daily cycling.

And hundreds more that only need rebalancing every couple years, or 200 cycles, or whatever the owner decides, based on a realistic delta spec.

Doing it according to some theory the closer is better is just a waste of time and exacerbates the problem especially if using top balancing anywhere near the datasheet max voltage.

Please stop giving advice as if every use case is close to your limited scope of experience.

 

[flippy]

I know dozens of packs that have not needed **any** rebalancing **at all**, well past 7-10 years of often daily cycling

i never crashed my car in in the past 20 years so seatbelts, airbags and insurance are bullshit imho.

you have proven time and time again you dont know the basics of (lithium) charging, so please stop commenting as if you speak as certainty or authority.

Please stop giving advice as if every use case is close to your limited scope of experience.

https://en.wikipedia.org/wiki/Psychological_projection


i domt mind if me or someone else is wrong, its a moment to teach and/or learn. but you need to be willing to accept you dont know what you are actually saying/recommening in the first place, especially if leads to dangerous situations.

 

[Wanda]

The BMS of JBD is good in china.
Very stable, good balance effect.

 

[Loydbrawn101@gmail.com]

Hello, I'm building an escooter and battery. Qs260 v4 8000w hubmotor,and spim08hp cells for right now to get me started. My question is about wiring a common port or separate port bms for charging only. I have a wiring diagram for a separate port bms for charging only. Just run a 2nd wire from the battery b- to the main discharge plug,that is suppose to bypass the bms for discharge. Is that correct?

Could I do the same for a common port bms? Have the C port and the battery + wire go to the charge plug. Run a wire from battery - to bms - and run a second set of wires from the battery+ and battery- to the main discharge plug?

I'm running 20s 1p right now but when i wire this up and figure it out I'm gonna do 20s 4p or 5p.

 

[kdubz954]

have two battery packs for my ebike. Both are 52V and one is 15AH/30A and the other is 20AH/40A. I am trying to find a way to change the maximum discharge amperage for both to 25A on the Xiaoxiang BMS. I have not had any luck finding the information anywhere. Can someone please give me an idea or point me in a direction? TYIA!

 

[amberwolf]

have two battery packs for my ebike. Both are 52V and one is 15AH/30A and the other is 20AH/40A. I am trying to find a way to change the maximum discharge amperage for both to 25A on the Xiaoxiang BMS.

Just to be clear, before changing anything: You want the BMS to shutdown it's output and completely turn off your system, no power to anything, once the current exceeds 25A?

(that is what would happen with a BMS current limit of 25A, for any BMS that has current-sensing capability *and* has an overcurrent shutdown option).

If instead you are trying to limit the system's current to 25A, you need to change the *controller's* battery current limit to 25A.

 

[john61ct]

I am trying to find a way to change the maximum discharge amperage for both to 25A on the Xiaoxiang BMS.

That BMS (like most) does not limit current, thus there is no such setting.

You as the user / designer of the system must ensure the current does not go near the max rating if the BMS.

To handle more current you must upgrade to a BMS with higher ampacity

or remove / bypass the existing BMS for discharging, use it for charging only.

Sent from my moto g power (2022) using Tapatalk

 

[kdubz954]

Maybe the problem is some ambiguity or misunderstanding in what you are trying to accomplish.
So a couple of questions.
Are you trying to take two battery packs and separate enclosures and run one BMS? How do you propose to accomplish that?

You state you have two separate batteries with different amp-hr ratings and different amperages.
How did you arrive at your amperage values? Amp-hrs are easy to calculate of course because that is merely the addition of your individual cell cluster amp-hr's in parallel.

Maybe you could shed a bit more light. Do you know what kind of cells and what their specs are in each battery enclosure?

Maybe a bit more explanation of your objective would help give you the direction you need.

Fair enough and yes there is quite a bit of ambiguity in my OP and my apologies for that. Yes both batteries are different AH and max continuous amps according the spec sheet where i bought them both. I am trying to run them both in parallel on a BBSHD. I was under the impression that using a "battery combiner" it would draw equal amps from both batteries (30A/2 = 15 Amps pulled from each battery) or am I totally mistaken? pretty sure the easiest thing for me to do is just limit the BBSHD controller to 25 amps overall. Thank you in advance for taking your time to answer my question(s)

 

[kdubz954]

have two battery packs for my ebike. Both are 52V and one is 15AH/30A and the other is 20AH/40A. I am trying to find a way to change the maximum discharge amperage for both to 25A on the Xiaoxiang BMS.

Just to be clear, before changing anything: You want the BMS to shutdown it's output and completely turn off your system, no power to anything, once the current exceeds 25A?

(that is what would happen with a BMS current limit of 25A, for any BMS that has current-sensing capability *and* has an overcurrent shutdown option).

If instead you are trying to limit the system's current to 25A, you need to change the *controller's* battery current limit to 25A.

yes I was trying to limit the current draw from each pack to no more than 25 Amps continuous as I am using the two batteries with different Amps ratings (30A/40A) with a "battery combiner" i was lead to believe this "should" distribute the draw evenly (as much as can be expected) between the 2 batteries but wanted to put something in place to make sure. I am probably wayyyy off base in my thinking but any input would be greatly appreciated. Thank you in advance.

 

[j bjork]

It dosent matter. The battery with lowest internal resistance will deliver most of the amps first (probably a very small difference), but they will even out to the same voltage.
They have to, as they are paralell..
It dosent matter if they are rated at different Ah and A, as long as the voltage is the same.

 

[kdubz954]

Thank you kindly for confirming. That does make sense in a way with my seriously limited understanding but i am trying to learn as i go. Really appreciate you taking the time to answer that for me. But yes both packs are 52V (well technically 58.8V or so iirc)

 

[kdubz954]

Will give you an alternative strategy that only represents fractionally more involvement from you and j bjork is correct btw.

Ditch the battery 'combiner'. Your plan is to carry both batteries on the bike at the same time.

Wow thank You very much Ebuilder for the detailed response. Definitely have given me quite a lot to digest and contemplate. Really appreciate the input!

 

[kdubz954]

indeed it always better to have more options available! I actually did kind of build my bike myself. It started as an E-Bike. I picked up a used Super73 Scout and installed the BBSHD from Lunacycle with the hot rod programming. My final plan is to remove the rear 500watt bafang geared hub motor and replace that with a sturmey archer 3 speed IGH. Not sure if posting images is frowned upon but here is a look at my baby-https://i.imgur.com/8PyQT4m.jpg

 

[kdubz954]

wow thank you so much! So much to digest. will definitely checkout the YT channel for HV have it bookmarked! I actually pedal this bike 95% of the time i really only use throttle (lightly) from a dead stop (intersections and such). the seat is wayyyy more comfortable than it looks lol thank God for high density foam. At one point I did look into the ASI Bac 800 series controllers and also mulled over the idea of using one or the Lunacycle ludicrous 2.0 controller but would want to be running 72V/100A battery at least. Great tip on the single speed as the sturmey archer IGH hub is a pretty big weak point in my dream build. Would consider a Rohloff if they were not 1k+ and had one that for a fatbike.

 

[PITMIX]

Hello do you have links for functional apps with the latest Antbms? There are many testimonials from people who have not been able to program their bms for a few months. Whether on iPhone or Android the problem is the same. It is possible to communicate and see the parameters but not to modify them. I went to the download site here for the latest version of the Android app.
https://rjxzstech.com/download/download-14-848.html
Personally I use the VBMS app.
https://play.google.com/store/apps/details?id=com.vortecks.vbms
I found this
http://www.mayibms.com/new/dynamic/
I got a testimonial from an iPhone user who managed to program his bms by clicking on "Fast setting" and then customizing the predefined settings.
Maybe this is the only way to solve the setting problem.
With some applications you have to enter the code 12345678 or 00000000
To be able to access and modify the parameters it is sometimes necessary to access level 5 with the code 123456789abc or 000000000000

On the new Ant bms it is possible to scan the round QR code with the Antbms logo to download the application.

You may have other links for functional apps and also for iPhone ? Thanks

 

[PITMIX]

Hi I come back to add a link that brings together several download possibilities for Antbms.
Newest version Android phone APP :
https://www.antbms.com:10001/apk/antbms.apk
OS iPhone APP search "antbms" in iPhone APP store.
video link :https://m.youtube.com/channel/UCGNnCIb3zniMo2SZf-LOB8A/featured
Computer software and manual download link :
http://mysharegadget.com/739077737

I also bought a usb connection wire for my smart Antbms, but I can't connect.
I thought this could solve the connection problems that some people encounter with bluetooth, but the connection with a windows computer seems quite complicated.
I downloaded the Antbms compressed folder I opened the Antbms software which is the same as on Iphone. I then connected the USB wire to my computer and to the bms in place of the LCD display plug. I started an automatic port search. My computer recognizes the COM8 PORT I installed the CH341 driver. Everything is ok but the communication is not done. I do not know why !
I think my BMS is not compatible with Antbms software because it connects with my smartphone only on VBMS v2 app, not with v1.This is a 2019 version model, it may not be intended for the 2022 version USB cable.
On the other hand, if you have a computer with bluetooth, you can install an Android emulator for example https://www.bluestacks.com and install the VBMS app directly from playstore on your Windows PC.
It will work exactly the same as on your smartphone.

 

[neilshep]

Hi folks - first post here. I've an Overkill Solar (XiaoXiang) BMS in my van, and after some challenges, I wrote a Arduino app on Adafruit's nrf52 series devices that lets you read cell voltages, overall SOC, current in/out etc. using BLE to connect to the BMS. This will end up, shortly, transmitted to an Android head unit (stereo) with a large display, so I can see everything up front. I've seen various code samples using wired, UART connections but not many using bluetooth.

The code is deliberately simple, and doesn't connect to a LCD display or anything. It's more intended as a starting point for anyone trying to use Adafruit's common nrf52 devices - they're reliable, compact and I've used them on several vehicle projects. Hope this helps!

https://github.com/neilsheps/overkill-xiaoxiang-jbd-bms-ble-reader for details.

 

[john61ct]

Wow!

On behalf of the community, thanks for a fantastic contribution.

 

[Oldspot]

Hi all I am fitting an ant BMS to a 24s (72v) battery
Every cell is balanced on the volt meter
Comes up with battery status - error
79v reading but only 53v after the BMS
I have set battery type, Ah etc
On the app max cell voltage 3.291, min 3.255 avg 3.288
Pack voltage 72.34v current 0.00A power 0w
Protectinfo open line
Warning info cellpackvoltrelatedprotection
On the individual cells I have the same high and low, except cell 7 and 9 read 4.88 on the display but not on the volt meter.
Any ideas?

 

[eee291]

A link to the BMS would be helpful, and show us how you connected it.
I have used ANT a few times, and it can be a bit confusing because the way to connect cells is different depending on model.

 

[Oldspot]

Ok so I have sorted connection, all cells reading correct and balanced.
When I turn the BMS on I get an audible beeping, with discharge mosfet error.
If I rest the BMS it stops for a few seconds the comes on again.
Do I have a dodgy mosfet, can I fix it?