This is, by far, the best bms Ive used. Im currently using it on a 20s8p Li-ion battery and I couldnt be happier. It connects just like any other bms and the app is fairly straight forward to use and tells you everything about the health and status of your battery you could possibly want to know. I highly recommend.

I never had such a screwed up BMS. The hoops you have to jump through are insane. I WILL NEVER BUY ANYTHING LIKE THIS AGAIN. It’s so frustrating. I gave it one star only because I had to to submit.

Needed to replace a dead BMS on an ‘out of production’ battery.I found this BMS straight forward to install once the battery was out of its case and all of the wiring accessed. For the avoidance of doubt, I did watch several videos from others who had assembled their own batteries.Also VERY IMPORTANT:- DO NOT work with Lithium type batteries unless you are confident working around High Current devices. It is easy to get into a dangerous fire situation.The manual enclosed is good but has very small type. Also, gave me cause for concern in its instruction “waking up” the completed battery. However, there is a switch. It really was that easy (just switch it on).There is an app. Yes you need it to tell BMS what type of cell and how many. After that there are other very useful settings and possibly too much information Again, just like the manual, the type face is small.To date I am very happy to have saved my nearly new battery with the dead BMS.

Just installed in an SOK 12v 206 Ah that had a bms that stopped working. So happy with this device as setup was pretty quick and directions included would get you there if you have small print read ability but the online downloads are much better. Love the settings as parameters, chemistry and readability are very good but the push button switch makes it so easy to activate.I'm building a new 1200a 12 volt bank and will use more of this type but 100ah

Super...me sirvió para ensamblar una batería de lifepo4 de 100ah 20s voltios para un cuadriciclo eléctrico...llevo dos meses usando y el balanceado es perfecto

I only give 4 stars because of instruction manual lack of explaining the wire numbers. 1/2 star for this.After I figured out the wire numbers the next issue was the app. After using the default code to log in on blue tooth 1234 and then 123456 to change settings I was locked out. Neither code worked any more.To fix this issue I downloaded a older apk version of the app. The old version let me log back in with 1234, to change settings 123456 and then prompted me to for my own password.So far this have working but at the possible of security risk from downloading apps from a unknown source. Another 1/2 star for this.

The BMS's have a password quirk. When you connect with Bluetooth it promps you to change the password you used to your own. Thats when the fun starts. You are now locked out until you spend 3 days trying to find out how to get back in it. The easiest thing I can say is write JK-BMS thru Amazon and they will generate you a code that lasts for 15 minutes. Chances are it will work for 15 minutes because your now locked out again until you get another generated code from then and then it happens again because you still didn't do it right. Its because the passwords you change it to don't stay in. Its not you ... so the other way is to go online to Off Grid Garage on YT and find the code generator page. Then you can generate your own codes until you finally figure out how the new password sticks. Mine are finally dialed in. What a nightmare it was,

Update 2024-12-14:Actually looking like top balancing will recover 20% capacity.Heater puzzle solved. See below for info from JK BMS.The scene:After 6 years, converting two (24v) 8S 200Ah bottom balanced LFP cells to a single 16S 200Ah 52.1V battery. Installed BMS 6 days ago.The good:Super simple install.Connected to app immediately.Clear and easy to read manual (yes, really!)The great:Chugging away at top balancing the pack.At 2A, and as poorly balanced at the top these cells are, it’s made decent progress. Looking like I’ll be able to reclaim an easy 10% MORE capacity from these cells than I’ve ever had.The “Meh”:Can’t figure out WHEN the heater port will activate.CAN cable was missing.Only JK protocol supported CAN menu.Over All Grade: A+Would I buy it again? Yep, as a matter I already have.If I figure out how to trigger the heater, I’ll update this.If I figure out how to get this to talk to my Victron gear, I’ll update this.I’ve played with pretty every setting. It works as documented.2024-12-17 JK BMS sent info:Heating Function Activation Conditions:The heating function for charging will be activated when Condition 1 is met, along with Condition 2 or Condition 3.Condition 1: The battery temperature is below the charging low-temperature protection threshold.Condition 2: Heating is manually activated via the APP, without checking the charger status. Once the low-temperature condition is met, heating will begin, which will consume battery power.Condition 3: The charger is detected as being plugged in. This function is related to the hardware of the protection board and the charger, so please confirm the technical specifications before ordering.Heating Film Selection:Step 1: Determine the maximum battery pack voltage. For example, a 20-series LiFePO4 battery has a maximum voltage of 20 × 3.6V = 72V, while a 24-series LiFePO4 battery has a maximum voltage of 24 × 3.6V = 86.4V.Step 2: Calculate the resistance value of the heating film. The resistance value is calculated by dividing the maximum total voltage by the current:Resistance (Ω) = Maximum Total Voltage ÷ 3A.For example, 72V ÷ 3A = 24Ω. Based on this, select a heating film with a resistance close to this value.A suitable heating film specification would be 72V/24Ω/216W.Key Notes for Understanding:Condition 1 (Low-Temperature Protection): The heating function will only be triggered if the battery temperature drops below a certain threshold (often around 0°C to 5°C) to prevent damage to the battery and ensure it remains functional during cold weather conditions.Condition 2 (Manual Activation via APP): This condition allows the user to manually activate the heating function through an app, which will begin heating as soon as the low-temperature condition is met. However, this will drain battery power, which is important to consider in terms of overall efficiency.Condition 3 (Charger Detection): The heating function is also dependent on detecting whether the charger is plugged in. This ensures that the battery is being charged during the heating process, avoiding unnecessary power drain when not connected to a power source.Heating Film Specifications: The heating element (heating film) needs to be carefully selected based on the battery's total voltage and required current. The resistance of the heating film plays a key role in determining how efficiently the heat is generated without exceeding the system's power limits.