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NEEY active balancer instructions?

mfred68

New Member
Joined
Aug 17, 2022
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70
I just bought a NEEY active balancer, its 4th gen, 10A and i just connected it to one of my 6 in parallel batteries, set the parameters and switched the balancer on. After a couple of seconds the battery bms lights went out and i had a total blackout as the whole system shut down
After it came back on (with balancer disconnected) i had a high voltage alarm on the consol screen.
The battery i had the balancer connected to now only shows a 25%soc where as before it was showing 80%soc like the other 5.
Have i just damaged the battery, or does the bme recover itself after a couple of full cycles? Or should i reconnect the balancer again but with the batter switch turned off? Please advise how i should use the balancer on a parallel connected active system.

Thanks
 
It sounds like maybe a couple of balance wires got crossed and the balancer caused an out of limit voltage spike or drop.

When using the NEEY turn off the built in balancer in the BMS.

At this point you should review every wire connection and verify the numbers, labels and wiring diagram. Voltage at each pin position of the wiring harness connector should be verified BEFORE plugging into the balancer.
 
It sounds like maybe a couple of balance wires got crossed and the balancer caused an out of limit voltage spike or drop.

When using the NEEY turn off the built in balancer in the BMS.

At this point you should review every wire connection and verify the numbers, labels and wiring diagram. Voltage at each pin position of the wiring harness connector should be verified BEFORE plugging into the balancer.
So the answer is to turn off the battery bms? No wires were crossed, I had good readings prior to turning on the balance function 15 batteries were at 3.32v but one was at 3.29v and it was highlighted in blue, to I switched the balancer on and the problem described above happened. So should I balance with the bms off or disconnected all together from the batteries?
 
Sorry poorly worded response on my part. Battery BMS must stay on. The recommendation is to Disable the Active Balance feature on the BMS, if it has one, when using a 3rd party stand alone balancer like the NEEY.

So if its not a wiring problem then there has to be something wrong with the NEEY unit. Cell voltages of 3.32 and 3.29 would indicate you don't need the NEEY balancer at all.
 
Sorry poorly worded response on my part. Battery BMS must stay on. The recommendation is to Disable the Active Balance feature on the BMS, if it has one, when using a 3rd party stand alone balancer like the NEEY.

So if its not a wiring problem then there has to be something wrong with the NEEY unit. Cell voltages of 3.32 and 3.29 would indicate you don't need the NEEY balancer at all.
The reason I got the neey was because the battery in question originally went faulty because I slug found its way onto the bms board and shorted the components and basically blew a hole in the monitor chip and transistors were fried. I took it upon myself to repair this bms circuit which was difficult but successful, and the battery has been working great for a couple of months since the repair, but it always showed a slightly different soc compared to the others and always triggered the high voltage alarm on full soc, and always reached full soc 100% while the other 5 were at about 80%, so I guessed that the batteries were not balanced, so I bought the neey.
Unfortunately after connecting it, and after the blackout caused, that battery you now showing around 50% less soc than the other 5, will the bms recover and put things right by itself or do I need to do something to make the battery show the same soc % ss the others, because they were all at the same soc prior to the incident.
Another problem is that I cannot access the bms settings, they are Bluetooth, but the app keeps stopping. It's the xBMS app as per the instructions. The batteries are made Rahvolt.com
 
So based on this latest data the repair may not have been as successful as stated. Have you looked into the brand and availability of a replacement BMS. I'm guessing there isn't much in the way of service or spare parts from the supplier or manufacturer. Worst case the factory BMS can be replaced with a generic brand so the battery can still be used.

Not sure if you are using closed loop communications.
 
I'm not 100% sure if I have a closed loop communication or not. The batteries (6 in total) are wired in parallel for the power, and in series for the communication rj45 cable which only uses 3 wires which in turn goes to the cerbo gx. I have a Victron multiplus ii connected to the cerbo gx too, and my display screen shows the soc of the battery bank, so I guess it's a closed loop communication?
Regarding the repaired bms, I have attached a screenshot from the NEEY app of that battery. Should I be concerned that one cell (in blue) is below 3.3v or is ot common that this happens?
 

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Differential cell voltage of 33mV is not necessarily an issue with the battery in the middle of the flat part of the curve.

Cell balancing cannot accurately be achieved unless the cell voltage level is at the top or bottom "knee" of the charge curve. This is why active balancers are set to start balancing only when the first cell hits 3.4V. Once this voltage threshold is reached then balancing should be allowed to continue until all cells are within 10mV.
 

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I purchased the larger NEEY 15A active balancer but have been unable to find a full set of instructions on how to use it.

I am hoping that someone has already used it, been through the learning curve and is willing to share the steps they used and what they learned.

The battery consists of CALB 230 cells, arrange as 2P8S for a 24 volt nominal battery which provides 460 AH. I have two cells that I would like to move charge from to bring them in line with the other cells.
For example, I have the following questions.
1. From BentleyJ's comments above, I will disconnect the REC-BMS passive balancer. My thoughts are to turn the REC-BMS off, and unplug the balance leads connector that goes into the REC-BMS as don't want it fighting with the NEEY. Are there any other steps that I need to take?
2. Do I balance with a charger attached?
3. If yes, what current do you suggest that I charge with?

Thanks in advance!
 
Balancing should be done while Float charging at a Constant Voltage of 3.45V per cell (27.6V). 15A should do a good job of balancing fairly quickly.

I have not personally used a NEEY balancer and am not familiar with the user set up menus. That said, make sure the Start Balance Voltage on the NEEY is set lower than the Charger Float Voltage so the balance function kicks in and starts working. Usually Start Balance is set at 3.4V per cell.
 
Balancing should be done while Float charging at a Constant Voltage of 3.45V per cell (27.6V). 15A should do a good job of balancing fairly quickly.

I have not personally used a NEEY balancer and am not familiar with the user set up menus. That said, make sure the Start Balance Voltage on the NEEY is set lower than the Charger Float Voltage so the balance function kicks in and starts working. Usually Start Balance is set at 3.4V per cell.
As I am thinking about your reply, (and by the way thanks for replying) I do have a question.

As I understand it, I will need to have a charge source on the battery while using the NEEY balancer in the same way that I am using a bench power supply set for 27.7V and 1.1amps, which is the most that the passive balancer can bleed off.

At 1.1 amps, it will take 150 more hours to fully charge. Using the NEEY it will do the job much faster. (I do have some concerns about surface Li+ ions only being moved but don't know enough about LiFePO4 chemistry to know if that's an issue.)

The NEEY can move 15amps. But given that I am moving charge and not bleeding it off, should use a charging source that puts out less then the NEEY can move?

Batt specs:
16 CALB 230 cells (testing shows that they are actually producing 240 Ah)
Arranged as 2P8S, giving me a 24 volt system with 480 Ah of capacity
Using a REC-BMS Q with passive balacing or approximately 0.9 amps

If I use the NEEY active balancer, my plan would be to disable the REC-BMS so that it does not compete or get confused by the active balancer.
 

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