j bjork
1 MW
I had mosfet fault twice in an ANT bms, I was able to fix it myself.
I have posted about it at least in my ktm thread, maybe here too.
I have posted about it at least in my ktm thread, maybe here too.
bluetooth BMS?
- Thread starter aethyr
- Start date
Your mosfet fault looks more like a bad contact on the cell cable. Sometimes a small wire is badly crimped or slightly cut at the JST connector and it is almost invisible.If there is no problem on that side and you have a permanent mosfet fault, you must open the bms and check the state of the mosfets. Maybe one of them is shorted. It will be quite easy to replace it. The most difficult thing is to find the Chinese sales site for the electronic component which will have exactly the same reference.
Here is the site to buy the original mosfets of my Ant bms 300A.
https://m.yoycart.com/Product/636910931901/
Here is the site to buy the original mosfets of my Ant bms 300A.
https://m.yoycart.com/Product/636910931901/
tmho
1 kW
Why do you want it to start balancing at a lower voltage? How low do you want?Oldspot said:
Not a dumb question at all. I do the same and typically set mine to start at 3.3-3.4V for larger packs.Oldspot said:
Cheers
Why start balancing at low voltage ? I set the balancing at 4.15v and end of charge at 4.18v.
Balancing from 3.8v is useless, it's energy loss. The bms will try to discharge cells with small resistors at the same time as the charger charges battery :?
It's like trying to inflate a flat tire
The ideal is to charge at a voltage slightly lower than 4.2v and let the bms work at rest to discharge the overcharged cells at a voltage of 4.15v for example.
After a few hours the bms will have discharged all the cells at 4.15v very precisely.
Balancing from 3.8v is useless, it's energy loss. The bms will try to discharge cells with small resistors at the same time as the charger charges battery :?
It's like trying to inflate a flat tire
The ideal is to charge at a voltage slightly lower than 4.2v and let the bms work at rest to discharge the overcharged cells at a voltage of 4.15v for example.
After a few hours the bms will have discharged all the cells at 4.15v very precisely.
It depends on the use case, quality of the cells and capacity of the battery.PITMIX said:
In my case I have some batteries in excess of 250AH that are used for solar home storage and are cycled daily. The tiny resistors have no chance of balancing in the small amount of time the battery spends at full charge each day and the cells are not perfectly matched so they need all the help they can get.
On larger capacity ebike batteries I also set the balance voltage lower as they need the extra help. It is not good to leave batteries on charge for extended periods either so having the balance voltage start earlier is the better option IMO.
Cheers
Starting sooner helps to make up for too low a balance current. Like if as is common your rig takes many hours or even days to finish.
Active balancers can work at ANY selected voltage e.g. bottom balancing
and if balance current is over say 2A then get the job done pretty quickly.
Active balancers can work at ANY selected voltage e.g. bottom balancing
and if balance current is over say 2A then get the job done pretty quickly.
Yes, agree with John here and I also use an active balancer on my largest home storage Lifepo4 battery.
It ultimately depends on how well the cells are matched. I have another home storage battery using 120AH LG LiPo cells that were well matched. That has been running without balance issues using just the bluetooth BMS balance resistors for over 2 years and hundreds of cycles.
My newer Lifepo4 battery is '280AH', and is an absolute disaster by comparison, requiring a 10A active balancer and struggling to maintain balance if discharged below 15%. I don't recommend Cahill store on Aliexpress. They don't match cells, lie through their teeth about the quality and make the customer run around doing pointless tests until the ultimate dispute judgement comes back from Aliexpress in their favor.
Cheers
It ultimately depends on how well the cells are matched. I have another home storage battery using 120AH LG LiPo cells that were well matched. That has been running without balance issues using just the bluetooth BMS balance resistors for over 2 years and hundreds of cycles.
My newer Lifepo4 battery is '280AH', and is an absolute disaster by comparison, requiring a 10A active balancer and struggling to maintain balance if discharged below 15%. I don't recommend Cahill store on Aliexpress. They don't match cells, lie through their teeth about the quality and make the customer run around doing pointless tests until the ultimate dispute judgement comes back from Aliexpress in their favor.
Cheers
The bms doesn't really balance, it just unloads overcharged cells. Triggering balancing while you're charging only slows down the charge and heats up the resistors unnecessarily. On the other hand, triggering the balancing function at a low voltage when the battery is not charging is surely a good thing to let the bms work quietly. I use this off-load balance feature when I get a second hand battery that is poorly balanced.
If the highest cells are at 3.85v and the lowest at 3.65v, I set the balance to 3.65v. After a night of work without using the charger my bms will have balanced all the cells at 3.65v.Then when the cells are all at the same voltage the bms never needs to rebalance unless a cell fails.
If the highest cells are at 3.85v and the lowest at 3.65v, I set the balance to 3.65v. After a night of work without using the charger my bms will have balanced all the cells at 3.65v.Then when the cells are all at the same voltage the bms never needs to rebalance unless a cell fails.
Has anyone managed to troubleshoot an Ant bms that won't start ? I have a last generation 8 to 20s model which lights up with a 3.7v battery.
The guy who mounted it on his motorcycle, connected the +/- of his 72v battery instead of 3.7v. I managed to turn it on once by connecting a 3.7v battery as in the photo, by connecting the battery in parallel to the power ON led. The problem is that today it is impossible to turn it on again using this method.
The guy who mounted it on his motorcycle, connected the +/- of his 72v battery instead of 3.7v. I managed to turn it on once by connecting a 3.7v battery as in the photo, by connecting the battery in parallel to the power ON led. The problem is that today it is impossible to turn it on again using this method.
thundercamel
10 kW
You're testing them with all 21 of the small gauge wires connected to a pack? Some BMS units also need the large battery negative terminal connected as well before they start acting normally.
No connection problem I usually use these bms. On the other hand, your remark can give a lead in troubleshooting. There may be a problem with the GND somewhere on the circuit. I sniffed the serial port with a little software to see the info that circulates between the bms and the computer. The communication seems correct, but I see that the hexadecimal cell voltage data indicates 64-00 for each of them.
eee291
100 kW
I just had the same experience today, easy to fix.
I have the 6-22S auto identify BMS from IC gogogo on AliExpress.
I'm using a 13s battery and have it connected like this:
I had to set it to 13S in the cell num field, this didn't change the cell numbers displayed in the app immediately so I did a reset by unplugging the balance wires.
It should display all voltages correctly now. If you leave the big b- disconnected B1 and B2 will have totally wrong voltages.
I have the 6-22S auto identify BMS from IC gogogo on AliExpress.
I'm using a 13s battery and have it connected like this:
I had to set it to 13S in the cell num field, this didn't change the cell numbers displayed in the app immediately so I did a reset by unplugging the balance wires.
It should display all voltages correctly now. If you leave the big b- disconnected B1 and B2 will have totally wrong voltages.
The reset is the first thing I tried at the time and it does not change the problem, unfortunately.
This bms has been defective since 2019 and I am looking into the problem only today.
I noticed that when disconnecting then reconnecting all balance wires, cells 1 to 15 display 3.6v. It's better than 0.1v but it's still an error since the cells are at 3.9v. Cells 16 to 20 indicate 0v. It only lasts 3 seconds then all cells show 0.1v. Calibration does not work. I even tested cell calibration for the 3 sec where the bms shows 3.6v but it doesn't work. However, I have no error message when sending calibration settings.
I also set the bms to 15s but that doesn't change anything. I even set the bms to 10s and disconnected half the cells and it's still the same.
I asked to James of :
https://www.lithiumbatterypcb.com/
if he could send me the update in .hex file, I am waiting for his reply.
I think there may be a bug in the bms program or a bad gnd power supply for the small processors that I circled in red in the image above. I recall that I have exactly the same problem on 2 identical bms bought at the same time.
This bms has been defective since 2019 and I am looking into the problem only today.
I noticed that when disconnecting then reconnecting all balance wires, cells 1 to 15 display 3.6v. It's better than 0.1v but it's still an error since the cells are at 3.9v. Cells 16 to 20 indicate 0v. It only lasts 3 seconds then all cells show 0.1v. Calibration does not work. I even tested cell calibration for the 3 sec where the bms shows 3.6v but it doesn't work. However, I have no error message when sending calibration settings.
I also set the bms to 15s but that doesn't change anything. I even set the bms to 10s and disconnected half the cells and it's still the same.
I asked to James of :
https://www.lithiumbatterypcb.com/
if he could send me the update in .hex file, I am waiting for his reply.
I think there may be a bug in the bms program or a bad gnd power supply for the small processors that I circled in red in the image above. I recall that I have exactly the same problem on 2 identical bms bought at the same time.
999zip999
100 TW
I'm having trouble finding a good working app that shows my cell level charge. Can any body have a link ? For xiaoxiang android BT. I have tried three of them and I can't find the old one on my old phone that works so well ?
eee291
100 kW
999zip999 said:
What android version does the phone have?
999zip999
100 TW
I keep getting rid of them because they are incomplete. Just a good working link for app. Which one do you like. I can't find the one I had as I lost my phone.
Here you go. 
Tomblarom
10 W
- Joined
- Jul 20, 2018
- Messages
- 93
Does anybody know why "JBD / Xiaoxiang Smart Bluetooth BMS" from wnsnty is offline?
bruno_mac_douglas
1 mW
- Joined
- Feb 20, 2020
- Messages
- 13
Hi Guys!
just put in service a 13s7p battery with a JBD-SP14S004 bluetooth BMS.
Some questions if anyone have any idea:
* some configuration recommended other than setting it to 13s ?
* is it normal than when I charge, "DisMos" is on and "balance" and "protection" are off ? I would have see it the other way...
* How much voltage difference is tolerable between cells ?
I was 0.011 when initiate charging now 0.021
*there is a switch pin on it, it is not documented in pdf, do you know how it works ? if I put a switch what will it do in shorted position ? I tried to short it shortly and I didn't see anything happen, was keeping charging like before.
Thanks!!
just put in service a 13s7p battery with a JBD-SP14S004 bluetooth BMS.
Some questions if anyone have any idea:
* some configuration recommended other than setting it to 13s ?
* is it normal than when I charge, "DisMos" is on and "balance" and "protection" are off ? I would have see it the other way...
* How much voltage difference is tolerable between cells ?
I was 0.011 when initiate charging now 0.021
*there is a switch pin on it, it is not documented in pdf, do you know how it works ? if I put a switch what will it do in shorted position ? I tried to short it shortly and I didn't see anything happen, was keeping charging like before.
Thanks!!
eee291
100 kW
Protection off just means that there are no fault conditions.
You have to turn switch function on first, if you short it discharge gets enabled.
It will accept a charge no matter the switch position.
You have to turn switch function on first, if you short it discharge gets enabled.
It will accept a charge no matter the switch position.
bruno_mac_douglas
1 mW
- Joined
- Feb 20, 2020
- Messages
- 13
Thanksss!!
