3S 11.1V/12V/12.6V 50A Balance Battery PCB Board with Balance

Ok, as a BMS; this works, I don't know if it can do the 50A since I have not driven it that far.Pros: Protection; I accidentally shorted the outputs and it shut off the power (good), and to switch it back on, just connect a charger for a sec and it turned back on.On the balancing aspect here are the voltages of my 3s battery pack after taking over 500WH from the 60p 3s pack;3.793.843.81The data above shows tight clustering of the cell voltages so it does balance. I am giving 5 stars for this device as it does what it says.Con: you have to remove the leads from the BMS to measure cell voltages.That being said, I think this little unit deserves the 5 stars as for me the con is not a big issue as the BMS is in the battery box anyway.

Turns off at the correct voltage, doesn’t get hot at all for higher current use, and overall does the right job.

Good communication

Gathering batteries for this project.Video service inoperable.Not tried yet.

After working well for almost three months, suddenly it stopped working overcharging my 3S lithium-ion battery to almost 13 volts, never disconnecting the charge. I noticed when I found my battery pack over heated at +45C. I consider this is not a reliable BMS.* The seller responded fast to my claim, saying they will ship me a new BMS.My battery is a 3S 400W/h Lithium-IonCharging power supply 15v 2.5 amp.Room temperature 65F.

Board received does not comply with published wiring diagram.Where does the battery main + connect to the board?

No p - protection Solder pad point so this won't safely work w my bms needed project not willing to chance burning up my devices

The media could not be loaded.  Pretty sure if the BMS is rated to handle 50 amps of draw that this should not happen at all. I took a closer look under the metal shield and found that one MOSFET gets hot while the others get moderately warm. What is wrong with my unit? I cant trust this to shut off the charging and discharging anymore as typically when the fets fail you're going to get a closed circuit and my lithium cells could explode. I'm glad that I tested this because otherwise I would have finished its enclosure and found out after it had set on fire. Bad product so far, and I don't know how I should trust other units of this same style (there are a lot.)

After using the cheapest 3s BMS’s on Amazon I decided to try this one which was double the normal priceAnd with great hesitation and skepticism about whether the extra money spent was going to even make a difference I connected it to my 3s40p pack and let me tell you that within 30min it brought my usual 30-50mv deviation down to under 10mvI couldn’t believe it, that’s the tightest cluster iv ever hadIt sustained a 12v 20a load without even getting warmThe one sent was different then the pic, the one received I would consider a N-channel only BMSSo there is no P- only C- and B-B- go directly to absolute zero along with the black balance wire, use a decent gauge for B- as this is the wire that all the current goes throughC- is your charger negative and is also you load negative ( P-), both C+ & P+ come directly off absolute + which can technically be 1 wire as your discharge and charge are the same giving the BMS control over the N- channelIt’s only using the small wires for balance sensing and not actual energy draw unlike the cheaper ones these balance wires won’t start to melt under loadMy charger maxes out at 18 amp but it accepted it without hesitationDefinitely 5 out of 5 even though I had to figure out wiring schemeHaven’t been able to test under voltage at my pack is almost 98% but will update soon as I can

Do not rely on this ti balance charge your pack. The way it claims to balance is just plain dangerous. Lithium ion batteries should NEVER be charged above 4.2 volts for any reason... It claims to charge the cells just above 4.2 volts and then drain the high cells through a resistor beeding the excess energy as heat... very inefficient but for a tightly matched pack like mine (18 parallel, 3 series, matched to 50mAh out of ~30 000 mAh) it's good enough and you're not bleeding much energy and the lost heat comes out of the charger anyhow... here's the issue. My pack never recharged, not even once, no power source no matter how big or small could charge it. Later I tore apart the pack and measured the series cell banks of 18 parallel cells. So 2 cell banks were beyond dead, like 0 volts and 0.5 volts... lithium ion shouldn't go below 3 volts per cell. The other cell bank was at 4.25 volts... I'd say that's way way out of balance. So this not only doesn't balance the cells, it caused tested good cells to go way out of balance. All my cells held charge for more than 2 weeks and this unbalanced then in 2 days.However. It did cut off the charge and discharge when any of the banks went above 4.2 volts or below 3 volts respectively... or my home would have a scorch on the siding (first charge should be outside where fires can cause damage). So while it caused a dangerous situation, it did prevent the cells from exploding. It also has some overcurrent protection, not sure what max current trips it, but it's somewhere below the maximum safe current for my pack (1 amp per cell, times 18 cells parallel, 18 amps safely both dorections). This seems to trip around 5 amps maybe up to 10 amps, not the rated 18 amps my pack could safely deliver.So for basic charge and discharge protection, good enough, but you need a dedicated balancing board because this won't balance the cells... and in my case it actually made the issue worse.