bluetooth BMS?

[ebike11]

Not sure sorry.

Its ok thx
I have 1 more issue. How do you guys turn on and off the bms?
I tried an on off switch on the 2 wires on the jst plug on the side of the bms and also a momentary switch but the bms still remains on.. So strange.

[serious_sam]

How do you guys turn on and off the bms?

I leave mine on 24/7. Current draw is negligible. I have the standard Bluetooth type. No display or lights or anything.

Apparently you can connect a switch to one of the temperature sensor inputs and program the BMS to deactivate the mosfets below a set temperature (seen when the switch shorts out the temp probe). But it isn't a full "off" switch. It just shuts off the output. Haven't tried it myself but sounds feasible.

[nardcox]

I have 1 more issue. How do you guys turn on and off the bms?
I tried an on off switch on the 2 wires on the jst plug on the side of the bms and also a momentary switch but the bms still remains on.. So strange.

I use the switch on the side and all lights will go out.

I have another issue:
https://photos.app.goo.gl/G9gF6pL7b1H939Dr6

Discharge Tube is Abnormal.
Didn't find anything... Anyone any suggestions?

[Golyo]

I have two questions:
1. Does anyone have bad experiences buying from LLT power? https://www.lithiumbatterypcb.com/
2. Would it be a problem to have 4 of these bms's next to each other? How easy it is to switch between them when trying to communicate with one and then the other and so on.
Plan is to have a four 17s batteries to create an extra plugin battery for a Prius.

[Magsy]

No issues ordering direct and shipping to UK, although very much the usual China quirks.

I have two side by side without issue, the iOS app lets you select by name (and you can rename, although it’s not great for me)

[TazGill]

Hi All,
New here and I am building my first pack for a DIY eBike.
I am wondering if you could help me diagnose an issue I am having on a new ANT BMS which I bought from ebay, the seller is no real help as the manual is very basic.
Before connecting this to my main battery which will be a 14S8P samsung 25R cells, I decided to test the bms bluetooth out. I made up a 7S1P pack and connected the balance wires as per the diagram. I have connected it to the charger (Bench power supply set to 31.5V) and do not seem to be able to see a charge, however I do see pulses of peaks of voltage and current of around 5A followed by 4-5 beeps with a red flashing light. Anyone able to shed some light on this for me? Or does anyone have a manual for the iOS app?
I dont really want to connect this up to my proper battery just yet as it has taken a while and money to build
TIA

Taz

[patrickza]

I have a ANT 16s 100A BMS. The problem is, the bluetooth goes offline after a while even if there is a constant draw of current. To wake it up, I have to manually use a extra 3V-cell and connect it with the two designated wires. That is most unconvinient.

Anyone knows how to solve this issue. Maybe some changes in the settings?

My bluetooth turns back on automatically when I either connect the charger or take it for a ride.

[Merlin]

first time i run into weird problems.

an old battery with 10S LLT bms installed quit the discharge fets.

so the APP either the PC software report with ANY errors that discharge is OFF (charge enable)

if i try to enable or disable it via PC it doesnt work.(switching on/off charge port works)
also tried to disable temp sensors but no success.

i know its pretty cheap 10s bms but it worked quite good and replacing it sucks just about the time factor.

any ideas?

[Cowardlyduck]

I posted this over on the DIY powerwalls FB group also, but thought I might ask here in case anyone's seem similar.
Has anyone seen this kind of thing before?
My BMS seems to be generating AC to it's casing. My BMS is touching onto my cell casings also. It dissipates very quickly and does nothing when shorted, but I can see about 500ma across it also. My battery is approx 57-58V fully charged so the ~100V AC seen is probably just that doubled, but it's strange to see it generating current.

DSC_6302.JPG (218.98 KiB) Viewed 756 times

Is it normal for a BMS shell to generate voltage of any kind like this?

Some of the suggestions from FB were that it could be the A/C ground (not shared neutral) on my battery box casing, or to do with the BMS mosfet switching frequency.
I'm thinking it's the BMS as my A/C is 240V anyway. I need to find the time to partially disassemble the pack and move the BMS out of the cell holder it's currently in, but the pack is still running fine at the moment.

Cheers

[Cowardlyduck]

I'll answer my own question...it had nothing to do with the BMS (Thankfully).
Turns out it was the ground as some suggested.
I'm just glad it wasn't the BMS as it would have been a huge PITA to disassemble the battery to fix that.
I still don't understand exactly how a separated ground could be doing this, but maybe it points to another problem where another device (maybe my inverter) is generating voltage on the ground.

Cheers

[nardcox]

I have another issue:
https://photos.app.goo.gl/G9gF6pL7b1H939Dr6

Discharge Tube is Abnormal.
Didn't find anything... Anyone any suggestions?

Anyone? Finally the seller got back to me (holiday in China apparently). They asked me to restart (already tried that ofc), and then they said ship it back... That's like having no support. Is there anyone that might have an idea of what's wrong? Dont want to loose the BMS for over a month or so...

[j bjork]

Does the output turn off when you turn off the bms?
Have you checked the mosfets if it doesn't?

When a mosfet got shorted for me I got error, not abnormal. But I think it sounds similar enough to check, dont you think so?
My posts are just 2 pages back, so you must have seen them when you looked for answers.

[nardcox]

I assume with output you mean voltage?

Voltage on the + battery and - battery is 80.1V (20S @ 4.0V)
Voltage on the + battery and C- BMS is 77.2V
Voltage on the + battery and C- BMS is 80.1V with BMS on
Voltage on the + battery and C- BMS is 77.9V with BMS in error mode

I didn't find your post since I searched on 'tube' and 'abnormal'. Looking back at your post I do remember reading it but that is way above my knowledge level, I have no clue what you did exactly. I will take out the battery and inspect the BMS if I can see something funny.

I have three options now:
1. Send it back and wait
2. Send it back and wait but in the meantime buy a new one
3. Send it back and wait but connect it without the BMS so that I can at least attempt to continue with setting up the rest of the bike (lights, switches, etc).

EDIT: I've opened the BMS, all looks good as far as my non electrical engineering eye can see.
https://photos.app.goo.gl/QM4QRDUeZ66HfUPC6
https://photos.app.goo.gl/Ay6nXWr7jvS1Fgwo7

[j bjork]

That you get a high voltage when you measure dosent necessary mean that a mosfet is shorted, it can be small creep voltage that disappear as soon as you put a load on it. An easy test is if the bike still works when the bms is off.

You will probably not be able to see the problem by just looking at it, but it depends on what has happened.

[nardcox]

The bike doesn't work at all, regardless of the BMS.

What happened is that I switched the positive and negative on the controller. I can't do much more than look? I read that you measured each individual mosfet, but I'm totally clueless about how to go about such a thing.

[j bjork]

wtf?!

Is there a problem with the bms at all?
If you killed the controller it is not very strange that you get a fault from the bms, you have to start at the right end..
Do you still get the fault if you disconnect the controller and then turn on the bms?
You complain about bad support, but you dont say that you caused the problem yourself.

[nardcox]

Hmm..I posted this question on another forum as well with all the extra info, though I did it here as well, apparently I didn't, my apologies.

Yes I still get the error even when nothing else is connected.

I can still connect the controller to the pc and read the rpm when I turn the wheel manually and write parameters to it, so my guess was the controller is fine,the BMS isn't.

[j bjork]

You said your bike dosent work, regardless of the bms. So I guess you have bypassed the bms, and the bike still dosent work?

But anyway, if you still get the fault even when nothing is connected to the output of the bms there probably is something wrong with a mosfet or something. You can try with light bulbs on the output, and see if it is possible to turn off.
If its not, then there is a problem. If you cant fix it yourself, you might as well send it back.

[aethyr]

Can anyone explain this? The app and the BMS itself is claiming that the 11th series battery is 0.1V and that the 10th is 4.9v. This is patently false because I checked each series with my multimeter and every battery is roughly 4v. And we also can tell that the 10th and 11th series voltage is wrong because if you actually add every group up it should be about 77v (according to the reported voltages), but the total voltage is shown to be 80v, which means that each series is roughly at 4v.

Finally the app's own "CellLow" is shown to be 3.975V and not 0.110V, and the cell high is shown to be 4.069, not 4.99. The BMS won't charge and then out of the blue, maybe after a few minutes or more, it starts charging and when I look at the cell voltages, the 10th and 11th cells are now fine.

I've wired up as charge only, BTW. So NEG battery wire to B- on the BMS and CHG- to C- on the BMS.
Any ideas?

[thundercamel]

The balance wire between 10 and 11 has a problem?

[flippy]

broken connection. check the wire from the battery right up to the connector and check the connector itself.

[nardcox]

You said your bike dosent work, regardless of the bms. So I guess you have bypassed the bms, and the bike still dosent work?

But anyway, if you still get the fault even when nothing is connected to the output of the bms there probably is something wrong with a mosfet or something. You can try with light bulbs on the output, and see if it is possible to turn off.
If its not, then there is a problem. If you cant fix it yourself, you might as well send it back.

Sorry for the late reply, had some crazy days at work.

I haven't bypassed the BMS yet. I meant it doesn't matter whether the BMS is on or off, the bike doesn't work.

I still get the error even when nothing is connected. I've made a video and some pictures if anyone care to take a look, I really don't see anything wrong / burned / melted. There are some pictures and a video or the BMS taken apart.

https://photos.app.goo.gl/rWyHYPyg7BZbEREW7

It should be fine to hookup the battery minus directly to the controller right? I'll connect everything and turn on the fuse last?

[j bjork]

It should be fine to hookup the battery minus directly to the controller right? I'll connect everything and turn on the fuse last?

Yes, you will get a spark somewhere when the battery and controller gets connected. In the fuse or in the contacts. I dont think it will be a problem if it is a dc fuse, if it is ac it might be more sensitive. But my guess is that it will not be a problem anyway.

If no mosfets are shorted, but the bms think there is a problem it wont turn on. So to bypass the bms will be the easiest way to test if the controller works.

[Andrewol]

Does anybody know can this bms be used to track the bike in case of theft?

[eee291]

It's a Bluetooth BMS not a GPS BMS