bluetooth BMS?

maSch · Nov 15, 2020

this is the one I have here
My build is actually in carcase stadium, hope to proceed to wiring in the next weeks
I wonder if it is a good idea to wire that BMS in the power circuit or -alternative- only in the charger circuit.
Has anyone here the same model/make and success wiring it in the power circuit, that is to say, decharge runs through these two parralelled wires.
I am expecting 200A peak at 96V

j bjork · Nov 15, 2020

It looks like you will use the display for it. If you dont wire the bms in the power circuit the remaining battery capacity will be totally wrong. It dosent seem to matter if you set up the voltages for the remaining capacity, it uses the drawn and charged Ah for the calculations anyway.

The mosfets seem a little sensitive when turning on the bms. I have blown one discharge fet when turning on, and a charge fet when turning on the bms with connected and powered up charger.
Now I first turn on the bms, then the contactors. So there is no load when the bms turns on.
I run 22s at 90v and 300A peaks.

maSch · Nov 15, 2020

hey, thats valuable info, thx
and yes, I plan to take advantage of the display info.
so you use exactly this make of it in one of your incredible builds? On the KTM I suppose?

Ok, so I need to figure out a wiring scheme where it is possible to power up the BMS before the rest of the bike.
Or would it make sense to insert a sort of precharge resistor, like Kelly recommends for the main contactor?

j bjork · Nov 15, 2020

Yes, on the ktm.
There is some sort of built in pre charge in the bms. You can set up allowable pre charge current, I think 60A is max. I would sometimes get pre charge failure when turning on, so I guess my controller takes too much at startup for the bms to handle.
It would probably be possible to run an external pre charge to turn on before turning on the bms, but for me I could just as well use the contactors and the pre charge I already have for them.

nardcox · Dec 4, 2020

I get the error "Abnormal start" on the Discharge MOS when I turn on the BMS.
Since it cuts of the discharge nothings working.

Searched the thread but didn't find anything. Also tried closing and re-opening the discharge and obv did a factory reset but the problem persists.

Valopallo · Dec 4, 2020

What does this mean? The charger keeps blinking green and does not charge. Maybe it is because of the voltage difference or is there a bad cell? Draining group 14 does not help when it's connected to other groups. I assume that would also be the case when charging the weakest group....? The groups seem to balance each other well except the group 11. Also, as a side note; the group 14 has the main discharge tinned to it and the group 11 seems to be missing two nickel strip connections(from 10-11) that obviously would lower the resistance. Could these cause the voltage difference and block charging and balancing of that cell group? The short question is, if I just weld more nickel to that connection can it solve my problem or do I have to disassembly the whole battery to check the cells individually/change them? Or would it charge only the group 11 if I put +5V straight to it even if it's connected to other groups and other groups don't seem to balance that? These are refurbished cells.

thundercamel · Dec 4, 2020

The balance between the cell group voltages looks close enough to me, where I wouldn't worry about it right now. Measure the voltage coming out of the charger with a DMM (multi-meter), and the voltage at the charge connector that you're plugging it into, and then report back.

Most chargers have a basic short protection on the output that will enable if there's a short (green light goes out). It retries rather quickly, and could be creating the blinking cycle that you're seeing. Inspect where those charge wires are going to.

Valopallo · Dec 4, 2020

thundercamel said:
The balance between the cell group voltages looks close enough to me, where I wouldn't worry about it right now. Measure the voltage coming out of the charger with a DMM (multi-meter), and the voltage at the charge connector that you're plugging it into, and then report back.

Most chargers have a basic short protection on the output that will enable if there's a short (green light goes out). It retries rather quickly, and could be creating the blinking cycle that you're seeing. Inspect where those charge wires are going to.

This is the charger I'm using: https://bmsbattery.com/home/1137-18576-xt12-546v22a-li-ion-battery-charger-with-plastic-shell.html#/557-connector_type-open_wire

The weird thing is it starts blinking the green light right after plugging it into the wall and it does not stop. The output pulsates between 54.4V and 0.2V as the light blinks.

ichiban · Dec 8, 2020

Any one use this active balancing BMS with Bluetooth, RS485 :

1A/2A Active Balance BMS Battery Protection Board 13S ~ 24S 100A 300A CAN RS485 GPS APP Lifepo4 li-ion LTO 48V 16S 20S 60V 72V
https://www.aliexpress.com/item/4001192978656.html

They are expensive !

They claimed 0.6A, 1-2A balancing current (see table) depending on model. With all those fancy RS485 + Bluetooth, GPS module etc. at over 100.-USD. I asked the seller whether the GPS is for navigating, tracking riding route via google map, OR, I can remotely pinpoint the exact location of this BMS (with batt pack and the bike) in case someone rides it away. But the latter should need cellular network, right ?
Waiting for the answer.

But, are they really that good for the investment ? Or it is just nice to have (for tweaking) to precisely play with the parameters.

[Does it balance the pack all the time (when we turn on the batt pack and/or this BMS, NOT when in storage) ? I guess that if we leave it to balance all the time and it might drain the pack to death if something goes wrong.]

Should we really do that ?

EDIT : I think the above paragraph in blue I originally posted is wrong. Any programmable BMSs should be able to set balancing limit between certain HVC & LVC and NOT "balance all the time"

I never balance my pack at all after 2 years and 300+ charges and rides. It is 14S5P of LG18650MJ1. Though it is always off a bit (20-30mV diff btwn the highest and lowest S groups) but still in good condition and going strong. My current BMS is JBD 14S 60A and I never detect any serious problem with it, except that app on my phone crashed several times along the way. I uninstalled the old one and re-installed, worked evertime - usage data intacted. Another improvement is that the bluetooth range should be much longer, like wifi or even cellular network. So I do not have to be very close to the bike in order to check battery condition. But I have never seen anything available rather than that tiny bluetooth module that is effective only within 5-10 meter max.

This is the BMS link I bought about 2 yrs ago :

https://www.aliexpress.com/item/32794186005.html?spm=a2g0s.9042311.0.0.27424c4dyGaU27

And below is the new BMS I asked in this post (active balancing 0.6A, 1-2A) whether anyone use it before. Is it worth to buy one since it is not cheap ? I am considering one for my new pack of 20S3P Samsung21700-40T :

thundercamel · Dec 8, 2020

Valopallo said:
thundercamel said:

The balance between the cell group voltages looks close enough to me, where I wouldn't worry about it right now. Measure the voltage coming out of the charger with a DMM (multi-meter), and the voltage at the charge connector that you're plugging it into, and then report back.

Most chargers have a basic short protection on the output that will enable if there's a short (green light goes out). It retries rather quickly, and could be creating the blinking cycle that you're seeing. Inspect where those charge wires are going to.

Click to expand...

This is the charger I'm using: https://bmsbattery.com/home/1137-18576-xt12-546v22a-li-ion-battery-charger-with-plastic-shell.html#/557-connector_type-open_wire

The weird thing is it starts blinking the green light right after plugging it into the wall and it does not stop. The output pulsates between 54.4V and 0.2V as the light blinks.

The charger blinking by itself sounds suspicious. The 54.4v sometimes at the output indicates that it's not shorted, but it sounds like the protection circuit is activating anyways. That's a 48 volt nominal 13s charger anyway, and if you wanted a 100% charge for your 14s setup you'd need a 52 volt nominal charger that has 58.8 volts at it's output.

john61ct · Dec 9, 2020

ichiban said:
Any one use this active balancing BMS

No, but it is only "expensive" compared to super-cheap units without those comms options.

No one can tell you what extra price is "worth it" for extra features. Personally spending more to get good accuracy, build quality, reliability and longevity is the key. But of course adjustability and easy monitoring are also important.

> I asked the seller whether the GPS is for navigating, tracking riding route via google map, OR, I can remotely pinpoint the exact location of this BMS (with batt pack and the bike) in case someone rides it away. But the latter should need cellular network, right ?

Yes. Just use your phone!

There are hundreds of units designed for tracking a stolen vehicle, but they are not BMS, please (again) start a new thread for that topic

______
Balancing is rarely done well by any BMS. IMO focus on the protection of the pack, HVC, LVC, temperatures.

And get separate specialized balancing gear if your pack ends up needing more than the BMS can handle well.

And of course balancing should only occur at the SoC/voltage level you select, and as an occasional maintenance procedure, not while the pack is in use.

Balancing all the time would be a stupid waste of time and dangerous added complexity

ichiban · Dec 9, 2020

Thanks john61ct :

I am just looking for a better than my previous BMS (bluetooh, 14s 60Amp from LLT). After about 2 yrs, I guess there must be some better or much better products out there. But not much to my finding.

GPS tracking, like I asked, just try to figure from the seller whether it is for the rider own navigation while riding OR for tracking a stolen bike. No answers yet. So I asked here on ES whether someone has used it. Who knows, new innovations come out all the time. I'll just enjoy the new tech they market it. I know there has been some disagreements re the GPS/BMS issues on this thread. Not interested in joining that. Sorry to step on some nerves here. Just let it go, man.

"...Personally spending more to get good accuracy, build quality, reliability and longevity is the key. But of course adjustability and easy monitoring are also important."

Agreed with you, that's what I am looking for. Just buy it, use it and never look back. Hate products that require frequent maintenances. Is there such a product ?

This is an off-topic opinion, below :
One thing I found after reading ES for just about 2 years now. There is no summary/conclusion for most of the topics. There are tons and tons of opinions, sample problems, debate, but not verified conclusions. So people just have to spend time searching, reading, digging, debating, having fun, being frustrated endlessly. Should there be any, it would have saved enormous energy for mostly everyone. For examples, like this BMS topic, there can be a guideline for how to choose the right BMS for your applications, popular products, mods & tweaks, etc. It will be better in info-graphic style, not just plain text. And that can be arranged in FAQ style, do not have to be just basic guideline but can be deeper in detail. Occasional updates will help maintain freshness of the topics. That should be archived for reference where people need info quickly can come grab and go. Life on e-bike will be easier that way. For builds problems solving, people will ask, experts (or those with experiences, opinions, etc.) can answer in open Q&A discussion area, so not to mix essential/accurate/verified info with tons of opinions into cocktails. I know it is not easy this way, but will be much more organized and very useful if succeeded. Just think out loud.

john61ct · Dec 10, 2020

Forum websites make lots of money from the ongoing ever-repeating discussions.

Yes a Wiki is better for semi-static structured info everyone collaborating to build it and keep it maintained.

Will require a different website running different software, big big project

and only a tiny proportion of the traffic stats which is what drives advertising income to pay for the hosting fees

eee291 · Dec 10, 2020

john61ct said:
Forum websites make lots of money from the ongoing ever-repeating discussions.
look who's making bank, 6780 posts in just 2 years

Yes a Wiki is better for semi-static structured info everyone collaborating to build it and keep it maintained.
Stop! It's already dead

Will require a different website running different software, big big project
oof

and only a tiny proportion of the traffic stats which is what drives advertising income to pay for the hosting fees
also oof

ichiban · Dec 11, 2020

Re my own Dec 08 2020 3:11pm - seveeral posts earlier, for the above BMS I am interested in :

1A/2A Active Balance BMS Battery Protection Board 13S ~ 24S 100A 300A CAN RS485 GPS APP Lifepo4 li-ion LTO 48V 16S 20S 60V 72V
https://www.aliexpress.com/item/4001192978656.html

Can anyone tell me whether this BMS will be able to safely handle regen charged back for my system ? Batt 20S3P Samsung 21700-40T (72V, 12Ah nom / 84V 105A max cont.) with 8T GMAC geared rear-hub motor, Phase Runner, CA3 display from GRIN's. I plan to use regen brake extensively. Each braking should not exceed 30sec - 1minute max, may be from rather fast 50-60kmh. I have to ask here since it is difficult to get answers from Grin since their respond time is so irritating. It will be lucky if I can get answer from them within 7 days, while normally takes 10+days with various excuses. This recent purchase took me a few months (e-mailing back and forth) before coming to conclusion. Very reluctant to buy from them again - contacting them is the last thing I wanna do, unless it is very necessary. In addition to that their answers is not quite a focus/clearly answered to my questions. I really do not believe this thing still happens today in 2020. Do not know yet about their product quality/effectiveness as claimed yet. Hope Justin read this and quickly improve that.

Or should I go for this one from DALY ?? :

Daly 18650 smart Li-ion 20S 72V BMS 80A 100A 120A Bluetooth 485 to USB device CAN NTC UART togther Lion LiFePO4 LTO Batteries
https://www.aliexpress.com/item/4001322690751.html

, even more expensive (US$126.72 + shipping) but looks more robust and solid build. Seller said "There are some problems with the GPS because of authorization in the oversea market. So we don't sell the GPS now"

Also that what type of BMSs cannot handle regen charged back ? So to avoid in the future.

Thanks in advance.

ichiban · Dec 17, 2020

Further question : for the above BMS, what communication should I go for : a CAN or RS 485 ? and why ? It s a pity that the seller just do not know much about the products.

Thanks in advance.

BTW : I already ordered the above (from IC GOGOGO / Ali) JK-BD6A24S10P @ 100A/200A peak, 0.6A balancing current (adjustable), build-in bluetooth, common port, can handle regen charge back to 40A for few minutes, 2 temp probes, including those basic protection a decent BMS should have. Some of these specs are from the seller but not on their sale page. It is somewhat overspec with plenty to stretch for my waiting-for-parts system of 8T GMAC + Phase Runner + CA3 display + 20S3P of Samsung 21700-40T but I figure that should not stress this BMS at all - make it last longer. Experienced from a friend making some batt packs with not much overhead capacity BMS and cheap (1/3 of mine). He ended up replacing several more BMSs while mine (60A BMS from JBD on 14S5P 18650MJ1 running BBSHD on 27.5" MTB) is still going stong.

Alexkat · Dec 20, 2020

Hi
Can you please tell me what transistors are those in picture ? Some of them need to replace

EbikeAus · Dec 21, 2020

Hi all

I'm having an issue with my 4s 80 amp Lifepo4 bms mounted on 4s of 60ah CALB cells in a DIY power case I built.

When I charge with my 20 amp wall plug charger, the xiaoxang software dies.

It all works perfectly while discharging. My loads are up to 50 amps.

Would appreciate any input ✌

thundercamel · Dec 22, 2020

EbikeAus said:
Hi all

I'm having an issue with my 4s 80 amp Lifepo4 bms mounted on 4s of 60ah CALB cells in a DIY power case I built.

When I charge with my 20 amp wall plug charger, the xiaoxang software dies.

It all works perfectly while discharging. My loads are up to 50 amps.

Would appreciate any input ✌

Is the BMS hooked up with separate charging and discharging wires, or just one wire for both? Got a link to the BMS you bought?

EbikeAus · Dec 22, 2020

thundercamel said:
EbikeAus said:

Hi all

I'm having an issue with my 4s 80 amp Lifepo4 bms mounted on 4s of 60ah CALB cells in a DIY power case I built.

When I charge with my 20 amp wall plug charger, the xiaoxang software dies.

It all works perfectly while discharging. My loads are up to 50 amps.

Would appreciate any input ✌

Click to expand...

Is the BMS hooked up with separate charging and discharging wires, or just one wire for both? Got a link to the BMS you bought?

Hi

Yes I have separate cables for charge and discharge.

I'll try upload some images and link

https://imgur.com/a/NSGH70m

https://imgur.com/a/e8hI5YG

https://imgur.com/a/IBRUiUl

Thanks

EbikeAus · Dec 22, 2020

vipster76 said:
where did you buy the bms from i wouldnt mind getting my hands on one!

Aliexpress mate
I'd recommend it, apart from this issue I'm having ✌

EbikeAus · Dec 26, 2020

Does anyone have any clue, or experienced this issue?

eee291 · Dec 26, 2020

you could try a few things.
- try different version of the App
- connect with other devices. Android or even better, IPhone.
- disconnect all other devices from that box and use only the battery with BMS
- try other Bluetooth module
- check/post all app settings on here

EbikeAus · Dec 26, 2020

eee291 said:
you could try a few things.
- try different version of the App
- connect with other devices. Android or even better, IPhone.
- disconnect all other devices from that box and use only the battery with BMS
- try other Bluetooth module
- check/post all app settings on here

Thanks for the reply! I will do that.

I tried another variation of the app (see below)

https://imgur.com/a/ISwqPDl

At least this one shows charging but only has one screen with limited data. No individual cell voltage, which I like to have. (See below)

https://imgur.com/a/hqdoqpC

https://imgur.com/a/ZQOWS5K

I will do some more tests as you suggested.

Dishwashertaco · Dec 27, 2020

Greetings guys,
Just started having issues with my 14S7P battery with a JBD SP15S001 v.1.6 BMS (60A v.). Had issues finding the bluetooth module (no blue light) and my electric scooter cut power as soon as i would accelerate hard.
Decided to open up the sucker, and found a burnt resistor (?) on the board. Have attached a photo of how it supposed to look like, and mine :flame:

Unable to identify the marking, either its "10E" or "301" depending on the orientation you read it.

So my question is, does anyone know what this resistor does? What would cause it to fail?

Thanks in advance for any input!

Edit:
When further thinking about this, it might be worth mentioning that the 14awg charge cable in addition to a 14awg cable supplying a scooter horn was routed right on top of the resistor (inside the heatsink-casing) to save space. Max charge amperage is 7A and the horn is supposedly not using more than 0,2A (which i have not tested). But with 14awg and the amperages mentioned, heat transferred from the wires really shouldnt interfere with the resistor lying underneath? Charging and discharging are not done at the same time, so the resistor shouldnt heat up further from contact with the charge wire?

bluetooth BMS?

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