vipster76 said:where did you buy the bms from i wouldnt mind getting my hands on one!
from aliexpress, link is on 1st post
vipster76 said:where did you buy the bms from i wouldnt mind getting my hands on one!
keyne said:I've just ordered a 24s 100A one myself. A few questions you may be able to help with:
Do you know what Balanced turn-on voltage is? Is this the voltage when it starts trying to balance any cells that are slightly higher than the rest?
Do you know how the sleep power consumption makes sense? 200uA when in sleep mode is great, but how do you get it in and out of sleep mode? With the bluetooth app? Wouldn't it already have to be in bluetooth mode to connect to the app to know you've just turned it on? I think I'm missing something here...
It goes into sleep if there is no Bluetooth activity for 10 seconds. The app polls the BMS constantly for real time data, so as long as the app is open, there is activity.keyne said:Does it go into the sleep state by itself after a set time? Or is it only put into the sleep state if you use the app?
DirkB19 said:I purchased this 13s 30A Smart Bluetooth BMS from Aliexpress.
It arrived after 3 weeks.
Unfortunately my unit doesn't work. It was DOA (Dead on Arrival).
Bluetooth & PC connection work, but the problem is that the first cell reads 1.8 V incorrectly while my cell 1 is at 4+ volts.
Seller thinks the problem is in my "weak" connections but I have checked and re-soldered everything and I am pretty sure the problem is in the PCB.
Anyways when I measure the voltage on the PCB header (where the sensor-wires arrive) it reads 4+ volts for cell 1 on my Fluke.
Any tips on what else I could try ?
aethyr said:Did you wiring everything, including battery leads? I had the same problem when I just plugged in my balance wires, but didn't wire up my main battery leads.
cwah said:Is it this seller?
http://s.aliexpress.com/Mb2AbyUv
I'm having a dispute with the 15s 30a bms too. Charging doesn't work and seller gives me random instructions to make it look like I did a mistake
I got mine from greenbikekit.comDirkB19 said:Hi,
Is the same product available from a different (more reliable) seller ?
mattjrogers said:I have one of these BMS units. Just installed it a week ago and working through its functionality.
I alway hate when a board has conflicting markings - such as a separate place to solder P- and C-, but they tell you to put both wires on the C- tab. Why?
I use that same phone APP and it occasionally cuts out and I have to re-connect the bluetooth, but it does not lose any data in that case. The BMS must have on board memory because it saves the number of cycles the battery has seen, fault data, and capacity info. The app asks for a lot of permissions, but it uses GPS location data to calculate your speed and distance so it can take a guess at the remaining distance your battery can go. You can pull up individual battery cell voltages in use to see voltage sag at max power and other info. It has a cool lock feature where one tap on the screen on the Lock icon turns off the output power. Nice for when you just run into a store and don't want anyone accidentally hitting your throttle. But I can imagine that you lock the BMS and then your phone dies and now you can't get it unlocked until you charge your phone. Guess I need to finish hooking up my USB port on my battery!
I have not loaded up the computer software, but it looks more powerful than the cell phone APP. You can change a lot form the phone and could save yourself by having a higher LVC and then if you really need, you can change it on the fly to a lower value to limp home. For my LiFePo4, the LVC is 2.7v. I would like it to be a little higher, but in reality it will only be at 2.7v under sag and the resting voltage will be higher. Balancing may or may not work well. I don't see any current flowing when it reaches its cell overvoltage cutoff. My charger is a standard no-name charger, but I do see 1 amp of current on other packs and BMSs when it is in balancing mode at top of charge. I can't feel any hot resistors, but they are under an AL cover plate and are small 50ma ones, so they may be working. My pack is a large 48v 45AH, so I don't expect balancing miracles. It does have a setting where I can tell it to turn on balancing at a specific voltage. I set it at a low 3.4v and when the first cells hit that voltage, a Chinese character appears next to them, so perhaps that cell resistor is turned on and reducing the current from that point until the first cell hits HVC.
Overall I really like its functions and being able to check individual cell voltages while riding really makes it a cool piece of tech. I just have to figure out how to wrap everything up so that I still get bluetooth signal but have a waterproof and protected pack. Any ideas? Also, how would you mount a USB port on a battery so that it is waterproof? I was thinking to just put the USB circuit board in with the battery and have a micro-usb cord already plugged in. Then I can run just the cord out through a waterproof grommet/caulked hole in the pack. Do they make a waterproof cover for the end of a micro-usb cable?
This is very early morning with a 1 year old, so it may not be written well, but I will update if I have any issues.
lukas999 said:
hey guys
I set charge to 4,15 v per cell
after few hours this is my reading
this bms can't balance them or I doing something wrong ?
Thank You for Your Help
Lucas
Your charger is set to 4.15 V/cell, so 58.1 V? The total of the cell voltages in your screenshot is 58.6 V; not an exact match, but probably within the measurement tolerance of the charger and BMS.lukas999 said:I set charge to 4,15 v per cell
after few hours this is my reading
this bms can't balance them or I doing something wrong ?
Heycycborg said:Your charger is set to 4.15 V/cell, so 58.1 V? The total of the cell voltages in your screenshot is 58.6 V; not an exact match, but probably within the measurement tolerance of the charger and BMS.lukas999 said:I set charge to 4,15 v per cell
after few hours this is my reading
this bms can't balance them or I doing something wrong ?
So it looks like your charger is holding at the correct voltage, but the BMS isn't balancing. Next step is to look at the BMS settings. I haven't used this BMS, so I'm somewhat guessing here. Referring to inwo's screenshot upthread, the relevant settings would seem to be:
So the basic rule would be:
- Functions: Balance - should be enabled.
- Base settings: CellOVP - should be higher than charger voltage per cell. 4.2 should work.
- Base settings: PackOVP - should be higher than charger voltage total, so try 60.
- Balance settings: Start Voltage: should be lower than charger voltage per cell. If you want 4.15 V, enter 4150. You might want to bump up the charger voltage a bit to give yourself a buffer. And if you do that, you might want to bump up the CellOVP and PackOVP.
- Balance settings: Windows - Not sure what this is. Maybe how far it drains a cell before re-engaging the charger? If so, 50 mV seems reasonable.
Balance start voltage < Charger voltage per cell < CellOVP < PackOVP per cell.
And the gaps should be large enough to account for measurement inaccuracies. Make sense?
What are your settings for these parameters?
Glad to hear it worked. Can you post the settings you used? Also, your old settings, if you remember them, so we know what doesn't work.lukas999 said:I did like You suggest
after several hours pack was pretty much balanced
cycborg said:Glad to hear it worked. Can you post the settings you used? Also, your old settings, if you remember them, so we know what doesn't work.lukas999 said:I did like You suggest
after several hours pack was pretty much balanced