bluetooth BMS?

[john61ct]

You mean controlling external relays rather than running power through the FETs?

Yes, all the voltage based stuff is fine.

You just lose OCP

[SilverLine]

No, just only using the BMS as "charge only".. And connect the main negative wire directly from battery to speed controller. I am aware, that I loose some safety.
But thanks... And its also possible to se how many aH i put back in the battery when charging ?
Does it show how many mAh you put back in each cell ?

[thundercamel]

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

Thanks eee! I wonder how far the functionality of the 6 digit passcode extends to, but I did get the new software up and running.

I now own three of the 14s 60a JBD units from here. They turned out to be a v1.3, v1.4, and just now a v1.6 which seems to be a pretty big revision. Two of the mosfets and two of the shunt resistors are gone to make room for more balance circuitry, but at least these mosfets are rated at about half the RDS of the old ones.

KNB3308A 80V 9mOhm 80A
145N08A 80V 4.8mOhm 145A

I forgot to look at what values came programmed with this v1.6 unit, and pasted in the settings I was using from the v1.3 unit that it's replacing. If anyone reads the default settings from a v1.6 unit, let me know if the shunt resistor is still set to 0.2 mR please.

Open images in a new tab for full resolution. V1.4:


V1.4:


V1.6:


V1.6:

[thundercamel]

No, just only using the BMS as "charge only".. And connect the main negative wire directly from battery to speed controller. I am aware, that I loose some safety.
But thanks... And its also possible to se how many aH i put back in the battery when charging ?
Does it show how many mAh you put back in each cell ?

As far as I know, the JBD BMS only shows instantaneous voltage and amperage readings. Wattage on the smartphone app is calculated on the fly I believe, and anything showing capacity levels or mAh are estimated from the current voltage. There are adjustable parameters for what voltage your cells are at for every 20% of their capacity level to adjust that calculation it gives you.

[john61ct]

IOW really nowhere near accurate SoC.

Even the most accurate BMs at hundreds of dollars get maybe 4-6% accuracy at best.

[SilverLine]

No, just only using the BMS as "charge only".. And connect the main negative wire directly from battery to speed controller. I am aware, that I loose some safety.
But thanks... And its also possible to se how many aH i put back in the battery when charging ?
Does it show how many mAh you put back in each cell ?

As far as I know, the JBD BMS only shows instantaneous voltage and amperage readings. Wattage on the smartphone app is calculated on the fly I believe, and anything showing capacity levels or mAh are estimated from the current voltage. There are adjustable parameters for what voltage your cells are at for every 20% of their capacity level to adjust that calculation it gives you.

Thanks
I think I buy and test. I am using Spim08HP from Batteryhookup.com, and they are slightly out of ballance. I like the "active ballancing" feature...

[quamau]

I am about to connect everything after installing battery pack on the bike, cabling etc.

When I fire up anc connect the xiaoxiang app, by tapping on the lock on the dashboard, I see it switch from the "Lock" red circle status, which I set time ago while working on the board, to another state which should be working but it does not.

I get a "LT" red circle. Battery state / Basic Information says "Discharge switch: off"

My question is: What is the meaning of LT? Is it Low Temperature? I have only connected one temperature probe, which reads fine on the dashboard. Could it be that the second probe is needed? Indeed "Discharge low-temperature" is set to Yes...

[eee291]

You can disable unconnected temp sensors with the App or PC program.

[quamau]

I kinda remember it was possible via PC, but this requires to reopen the pack.

Can you be so kind as to show me how it can be done via app? All I can find is an option to switch from one sensor to the other on the dashboard...

Under "Params setting" my app shows nothing related to temperature...

[eee291]

viewtopic.php?p=1515412#p1515412

Check the pics on the post and make sure you are using the latest version of the App.

[newsky526]

Hi guys. I need your help. I also have such a Smart BMS and made a mistake: I flashed it with the wrong firmware from 10S. Now only 10 channels are visible. But I have the BMS 14S. Now I need firmware for this BMS (14S), a file in the SP14S.hex format. Thanks in advance and sorry for my english.....

[eee291]

You can unlock more channels without flashing a new firmware, all you need is the PC dongle and Software which I guess you already have.

[newsky526]

You can unlock more channels without flashing a new firmware, all you need is the PC dongle and Software which I guess you already have.

Unfortunately, this is not possible to do. Need the right firmware ....

[quamau]

A quick update on my little problem above: solved super-easily by controlling everything through the new app version (3.1.1013), works like a charm and allows to modify all the parameters which were only accessible via the PC program before.

Many thanks to eee291 for pointing me in the right direction

[eee291]

Glad it worked out for you and thanks for reporting your fix.
Most people just disappear afterwards and we never get to know what happens in the end.

[dirttorpedo]

I recently installed the following bms on a 20s pack.
https://www.lithiumbatterypcb.com/produ ... t-current/
I have it set up to charge and balance only, battery is connected directly to my controller on the discharge side. It works really well for charging and monitoring but I'm having an issue I can't figure out. Cell #20 reads really high when I charge. If I shut off the charger, it drops right back in line with the other cells. At the end of charging, it drops right back down with the other cells. Honestly, it wouldn't even be an issue except that once in a while, cell #20 reads so high that it kicks on the overvoltage protection. This basically makes it so my charger switches off and on about every five seconds. Is there some specific wiring issue that might be giving me this false high on my top cell?

[SilverLine]

I recently installed the following bms on a 20s pack.
https://www.lithiumbatterypcb.com/produ ... t-current/
I have it set up to charge and balance only, battery is connected directly to my controller on the discharge side. It works really well for charging and monitoring but I'm having an issue I can't figure out. Cell #20 reads really high when I charge. If I shut off the charger, it drops right back in line with the other cells. At the end of charging, it drops right back down with the other cells. Honestly, it wouldn't even be an issue except that once in a while, cell #20 reads so high that it kicks on the overvoltage protection. This basically makes it so my charger switches off and on about every five seconds. Is there some specific wiring issue that might be giving me this false high on my top cell?

This is almost always due to bad cells (cell20) with bad capacity, high IR or a loose connection in the very same area.

[eee291]

Yeah, I'd crack open the pack and confirm it with a Multimeter. My guess is a bad weld or solder joint.

[newsky526]

Hi guys! A good Chinese seller sent me (thank him!), all that is needed. New version of JBTools, firmware and instructions. Firmware for series from 11S to 20S. But I couldn’t flash it - for some reason my computer stopped connecting to the BMS. In short, I ordered a new BMS on Aliexpress. Files in the archive can come in handy for someone.

[john61ct]

Did you try with another PC?

USB / driver compatibility issues?

[newsky526]

Did you try with another PC?

USB / driver compatibility issues?

Yes,I try it.USB,driver is OK. BMS is due. Now I bought a new, the same BMS.

[john61ct]

Is LLT Power the best build quality / reliability / longevity out of all these various "Xiaoxiang type Smart BT" BMSs ?

https://www.lithiumbatterypcb.com/produ ... er-battery

JBD is the same company wrt these BMS?
https://s.click.aliexpress.com/e/OstYsoYY

[Merlin]

i see my link in the tiny bms thread helped =)

"the best" isnt out there...but it works great. BT is stable.
the ANT BMS i have severel post readed from online buddies with dead batteries. i installed it once (ANT) and the BT connection sucks pretty hard.

if you ask me, for that price, its one of the best right now.

[john61ct]

"the best" isnt out there

Of course it is, just means better than the others **within this group** discussed in this thread:

LLT "smart BMS" BQ76940 based) and compatible with the "xiaoxiang" app

presumably also giving compatibility with FOSS firmwares out there

https://github.com/smagicld/xiaoxiangBMS

https://github.com/BotoX/xiaomi-m365-compatible-bms


RJXZS seems to sell the same units?
https://a.aliexpress.com/n9xwVd1m

But I'm asking if one or more of these vendors are more trustworthy / reliable / genuine than the other dozens or so mentioned that "appear" to all be selling the same products. . .

[eee291]

Is LLT Power the best build quality / reliability / longevity out of all these various "Xiaoxiang type Smart BT" BMSs ?

https://www.lithiumbatterypcb.com/produ ... er-battery

JBD is the same company wrt these BMS?
https://s.click.aliexpress.com/e/OstYsoYY

AFAIK JBD makes them and everyone else is a reseller.
Lithiumbatterypcb stopped working for me, it always asks me for my phone number even though I have it saved, now I only use JBD's Aliexpress store.