bluetooth BMS?

eee291 said:

https://endless-sphere.com/forums/viewtopic.php?p=1515412#p1515412

Click to expand...

Thank you very much!
I went through the thread down to page 45, didn't saw your post. It should get more publicity!

Hello, in one of these bms there's a high-voltage sound alarm when a cell exceeds, say, 3.55v.? (for charging the battery lifepo4).
I found this picture that looks like yes?

Same problem as serious_sam here: newest app version does not work on Android 9, older does. Is there an authoritative place to look at for app updates?

Meantime be aware that older Androids can go for say $20 on eBay, cheap enough to dedicate one to a particular function.

john61ct said:

"cute elephant app"

Does that refer to what has been labelled the Xiaoxiang app?

are there lots of other bluetooth BMS that don't use that app?

And the Ant BMSs are completely different right?

And then there's the ones Em3v uses, any leads on how to get those?

I think it would be very useful, if we standardized some naming conventions?

Click to expand...

I proposed having some naming conventions. While ago https://endless-sphere.com/forums/viewtopic.php?f=14&t=88676&p=1354972&hilit=propose#p1354972

Two years later I still find this thread very confusing.

I think everybody means by now what "JBD" BMS are. (well labeled in PCB, same app, same chipset)
We don't have a name for the other ones.
I still miss a wiki to make this knowledge explicit

Yes too bad, no more wiki
https://endless-sphere.com/forums/viewtopic.php?f=32&t=94921

Each BMS type should get its own hardware thread, with links to top trusted quality ordering sources maintained in the OP.

And then each piece of the software they are all compatible with each getting a separate thread too.

I'm building a batterypack for a friend, using the JBD smart bms (xiaoxiang).

I've run into what looks like a double problem.
First the bluetooth module stopped working. It does not build any connection with the app and the phone does not see any bluetooth device. It did work before. The led on the module is permanent on. Measured 3.3 volt over it.

Secondly, the uart-usb pc module does work, but only half. When I start the PC software I can start the connection. It reads all the cell voltages, total voltage, capacity etc. It also detects if the discharge fets are switched on or off (with K1). But it can't read the eeprom anymore. There is very quickly a connection error pop-up, or a 'the serial bus seems busy' error.
This also did work before, reading and writing to the eeprom. Trying a different baud-rate has no positive effect.
I found out about this problem after the bluetooth module stopped working, but am not sure if it is related to that.

What I measured is that without any module attached, the rxd is 0 volt, and txd 3.3 volt (constantly). When the uart-usb is connected, both led's inside the module flash intermittendly, rxd has pulses from 0 to 5 volt, txd pulses from 0 to 3.3 volt.
With the bluetooth module connected, no data on rxd or txd at all. Voltage levels stay the same as without a module.

Does anybody know if the rxd and txd behaviour and voltage levels are normal?

Has anybody run into a problem reading the eeprom after using the newest android app where one has to set a 6 digit passcode? That was initially what I thought had happened. The passcode has been set, but the pc software does not send it to the bms because that option does not exist there. Hence the bms rejects the eeprom reading.
If someone could tell me that in their setup the pc software still works after android has set a passcode, than at least I can rule out that possibilty.

Thanks

I had a similar issue it was before the new app though, all I did was disconnect the balance wires for a while and it worked again.

Good to hear you solved it that way.
Unfortunately, mine have been disconnected for more than a week already. No change....

I guess you could try to flash a new firmware to it, I've seen a post with the file attached to it.

Here it is:
https://endless-sphere.com/forums/viewtopic.php?f=14&t=88676&p=1517242&hilit=bms+firmware#p1517242
DISCLAIMER! Only try this if you have no other option. Randomly updating and hoping for more features might leave you with a bricked BMS.

Hello,

I've run into a recurring issue with those smart bms. Got mine from jbd / aliexpress and there seem no way to make the switch work. (see attached pics) Altogether, I got 3 of those bms, and only one has a working switch. Any chance to fix this ? Or is it just very bad build quality.

Thanks for your time.

Well, problem solved it appears: I soldered the switch wires on the wrong side of the bms! I simply added more solder tin to have it flow all the way through the holes and make contact on both pcb sides, and now it seems to work.

So you installed a switch to have the BMS ignore the temp sensor inputs, or is the BMS acting as a switch output?

thundercamel said:

So you installed a switch to have the BMS ignore the temp sensor inputs, or is the BMS acting as a switch output?

Click to expand...

Those JBD BMS come with a "weak electricity" switch - as they call it - which basically cuts off power, though the tension is more like 15V, not 0. What it does it toggling the main output MOSFET, which is good enough to act as power cutoff. On the plus side, it sits behind the overcharge protection, so no risk of short circuit. This and the possibility to manually limit the max. charge per cell is actually the only reason I got those expensive BMS. In my experience, the whole BT + smartphone App hype is quite counterproductive, as a well built pack will rarely unbalance itself to a point where you'd need to monitor it constantly, yet it will discharge faster because of the additional BT drain, which might not be an issue during everyday use, but certainly is when putting the battery away for storage...

I kept the temp sensors, but had to solder them directly to the pcb, as my box is not wide enough to fit the jst connectors.

qwerkus said:

Those JBD BMS

Click to expand...

Are there BMS models featured in this thread with BT comms, that you would say are outside that "JBD" categorization?

> the whole BT + smartphone App hype is quite counterproductive, as a well built pack will rarely unbalance itself to a point where you'd need to monitor it constantly, yet it will discharge faster because of the additional BT drain, which might not be an issue during everyday use, but certainly is when putting the battery away for storage

Yes I agree. But many sub-optimal packs (and all top-balanced ones IMO) do benefit from such monitoring while in use discharging.

Yes that extra parasitic drain is an issue while sitting not in use, but personally I think that is true for **all** BMS

My solution is to not "embed" them fully inside the pack shrinkwrap, but bring the balance leads out and design the physical connectors and case so the BMS is easily removed and (when needed not if,) replaced, without disassembling the pack wrt the cells themselves.

I would do this even if the BMS featured a "completely off" switch.

And I definitely want a good BMS active, not only for HVC protection in case the charge controller fails

but also in use while **discharging**, so the LVC / alarms are based on the weakest cell/group voltage rather than that of the overall pack.

Especially critical if you top balnce, and might want those last few miles of range to get home some days

What should be idle consumptuon on this bms? We are getting 18.1mA with notging connected and no coms over BT? Seems excessive

That's why - and just one good reason - to easily be able to fully isolate the cells from everything else.

Some extremely crappy BMS actually pull more current from some groups than others, the accumulative effect on pack lifespan will be a huge hit on overall longevity.

To the point in some contexts if possible it wohld be worth using a buck converter from the full pack and feeding the BMS power input from that.

Or get a better BMS.

Thanks qwerkus, that's the first time I'm hearing about the switch feature.

john61ct said:

qwerkus said:

Those JBD BMS

Click to expand...

Are there BMS models featured in this thread with BT comms, that you would say are outside that "JBD" categorization?

but also in use while **discharging**, so the LVC / alarms are based on the weakest cell/group voltage rather than that of the overall pack.

Especially critical if you top balnce, and might want those last few miles of range to get home some days

Click to expand...

I've also seen Ant BMS units on this thread and AliExpress that seem like a good option. I have two of the JBD smart BMS units, and they drain so little they've barely made a dent over two winters of storage. I definitely want to monitor voltages just in case, and the LVC of each cell group I totall agree with. My packs are both uniform batteries, I top balance and I used a nickel strip per cell for series connections. At bottom capacity for max range, the groups vary greatly in their voltages, but always line right back up after charging.

OK it does look like Ant is a completely different setup, firmware components etc

Hi
I have an ant bms that need current calibration
I have the the pc tools software , what USB adapter do I need and where does it connect?

Thanks

What are you thoughts on this one? I cant seem to find the app either
I need a 200A or 300A BMS

https://aliexpress.ru/item/32963235751.html?spm=a2g0o.productlist.0.0.5e781710zntwg9&algo_pvid=8e9d6054-2697-4882-9691-3f9092760c13&algo_expid=8e9d6054-2697-4882-9691-3f9092760c13-3&btsid=0be3743615828941405281532eb75d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603

ebike11 said:

What are you thoughts on this one? I cant seem to find the app either
I need a 200A or 300A BMS

https://aliexpress.ru/item/32963235751.html?spm=a2g0o.productlist.0.0.5e781710zntwg9&algo_pvid=8e9d6054-2697-4882-9691-3f9092760c13&algo_expid=8e9d6054-2697-4882-9691-3f9092760c13-3&btsid=0be3743615828941405281532eb75d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603

Click to expand...

clean up your links. this shit dont work if you copy over the adress that is used to access YOUR account.

this is how your link supposed to look like: https://www.aliexpress.com/item/32963235751.html

the app has been shared by me several pages back, even different versions of it.

flippy said:

ebike11 said:

What are you thoughts on this one? I cant seem to find the app either
I need a 200A or 300A BMS

https://aliexpress.ru/item/32963235751.html?spm=a2g0o.productlist.0.0.5e781710zntwg9&algo_pvid=8e9d6054-2697-4882-9691-3f9092760c13&algo_expid=8e9d6054-2697-4882-9691-3f9092760c13-3&btsid=0be3743615828941405281532eb75d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603

Click to expand...

clean up your links. this shit dont work if you copy over the adress that is used to access YOUR account.

this is how your link supposed to look like: https://www.aliexpress.com/item/32963235751.html

the app has been shared by me several pages back, even different versions of it.

Click to expand...

Still requires me to sign in :lol:

eee291 said:

flippy said:

ebike11 said:

What are you thoughts on this one? I cant seem to find the app either
I need a 200A or 300A BMS

https://aliexpress.ru/item/32963235751.html?spm=a2g0o.productlist.0.0.5e781710zntwg9&algo_pvid=8e9d6054-2697-4882-9691-3f9092760c13&algo_expid=8e9d6054-2697-4882-9691-3f9092760c13-3&btsid=0be3743615828941405281532eb75d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603

Click to expand...

clean up your links. this shit dont work if you copy over the adress that is used to access YOUR account.

this is how your link supposed to look like: https://www.aliexpress.com/item/32963235751.html

the app has been shared by me several pages back, even different versions of it.

Click to expand...

Still requires me to sign in :lol:

Click to expand...

that is the site reacting to a old cookie. ali is a annoying site.

flippy said:

that is the site reacting to a old cookie. ali is a annoying site.

Click to expand...

Especially the last week. They seem to have changed anything. It was not possible to go to "shipped items" in my account. Always brought me back to login page. And I have NO IDEA why the urge me to login EVERY time I go to their site.