Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
adjustable Cheap Chinese Active Balancers
#1
Hello everyone,



according to this thread -> Cheap Chinese Active Balancers


(01-09-2020, 06:25 AM)daromer Wrote: Yeah you unlock some capacity but only IF your pack nominal current draw is lower than the balancer can balance. And for most users thats less energy gained than the cost over 10 years IF you look towards that cycling Them that Hard so you need to bottom balance you wear out the cells within a year anyways Smile


I think it disqualifies these balancers because the balancing-start-voltage is too high and you can't change the parameters.





But: has someone tested this chinese active balancer with bluetooth app?











-> Aliexpress







There are variants with 1A, 2A, 5A or 10A balancing current, and it comes with bluetooth and some values are adjustable via app.

But the description is very poor and I can't see which parameters can be changed in which range.

I installed the app just for testing but without having the balancer connected you only can change the language (between chinese and englisch).



So does anybody knows this balancer and can tell something about it?
Reply
#2
That one is really a passive balancer (you can tell because it does not have any inductors).
It will only bypass (drain) current from cells.
Also if it is bypassing the claimed (high) currents, that heat has to go somewhere, there are no heat-sinks so likely will overheat fast.
It may be OK for lower balancing currents.

Real active balancers are more complex & transfer energy between cells to equalize voltage.

It has been pointed out elsewhere on this forum that trying to do active balancing:
a) is not cost effective &
b) tends to hide problems eg self discharging or weak cells
Running off solar, DIY & electronics fan :-)
Reply
#3
Thanks for reply.

Which current would be usefull a balancer should be able to handle when we talk about
- 14s100p configuration and a minimum using of 5kWh every day
- used, 18650 cells, tested but mixed brands and models
Reply
#4
(04-17-2020, 02:55 PM)Stefanseiner Wrote: Thanks for reply.

Which current would be usefull a balancer should be able to handle when we talk about
- 14s100p configuration and a minimum using of 5kWh every day
- used, 18650 cells, tested but mixed brands and models

I actually bought that active balancer but haven't had the time to play with it yet. I use another active balancer right now and works great. Using an active balancer doesn't hide anything any more than a passive balancer. You can still tell which one is out of balance especially if you set a limit on the balancing threshold. For example my current active balancer only balances cells that are over 40mV difference. If one was to run-away you can tell that the one that is always on the high limit.

The key is logging the information. I bought the one with the bluetooth like the above, but they make one that also has a canbus interface. This will make it easier to log the information into my existing grafana interface. I now have to figure out how to use python to interface to my bluetooth only version. that's a pain.

You ideally shouldn't need much current transfer. 1-2A would be ample. If you find your cells move more than that then you have issues with your pack. A properly sized and balanced pack should have the same capacity. If I were to turn my balancer off my cells would be fine for months before needing another balance.
Reply
#5
Stefan passive balancer for that small should be enough to have 100-200mA balancing current.
The Ultimate DIY Solar and build place
YouTube / Forum system setup / My webpage  Diy Tech & Repairs

Current: 10kW Mpp Hybrid | 4kW PIP4048 | 2x PCM60x | 100kWh LiFePo4 | 20kWh 14s 18650 |  66*260W Poly | ABB S3 and S5 Trip breakers
Upcoming: 14S 18650~30kWh
Reply
#6
Ok so the 1A or 2A version shoud be Ok but you should have an eye on the system from time to time so you can see issues and they won't get hidden.

I found another interesting one: 

https://aliexpress.com/item/4000529723243.html

Seems to be a combination of the above balancer and the known smart bms including protection board,
so that seems to be an all-in-one solution.

I guess I will give the 2A / 300A version a try.

300A is max current, 150A continous and this is twice of what I wil use, so there should be some power and heat reserve.
Canbus or WiFi instead of bluetooth app only would be very nice but I can't find one.
Reply
#7
(04-17-2020, 01:13 PM)Redpacket Wrote: That one is really a passive balancer (you can tell because it does not have any inductors).

Talking about this: https://www.aliexpress.com/item/32945565819.html
It has huge capacitors and one big inductor (big white box next to capacitor).  So they're just using a design with one pump and a lot of circuitry to connect it to the right cells.  Vs the more often seen design of one pump between every cell.


(04-17-2020, 01:13 PM)Redpacket Wrote: b) tends to hide problems eg self discharging or weak cells

If it's possible to poll the status via Bluetooth, one could log how often charge was pushed into / pulled out of each cell, making it extremely useful in identifying bad cells.  Even distinguish between weak cell and self discharge problem.

PS. Haven't tested or seen review of the device. But anything else simply would not make sense or work at anywhere close to 1A.
Modular PowerShelf using 3D printed packs.  60kWh and growing.
https://secondlifestorage.com/showthread.php?tid=6458
Reply
#8
(04-17-2020, 11:20 PM)ajw22 Wrote:
(04-17-2020, 01:13 PM)Redpacket Wrote: That one is really a passive balancer (you can tell because it does not have any inductors).

Talking about this: https://www.aliexpress.com/item/32945565819.html
It has huge capacitors and one big inductor (big white box next to capacitor).  So they're just using a design with one pump and a lot of circuitry to connect it to the right cells.  Vs the more often seen design of one pump between every cell.

(04-17-2020, 01:13 PM)Redpacket Wrote: b) tends to hide problems eg self discharging or weak cells

If it's possible to poll the status via Bluetooth, one could log how often charge was pushed into / pulled out of each cell, making it extremely useful in identifying bad cells.  Even distinguish between weak cell and self discharge problem.

PS. Haven't tested or seen review of the device.  But anything else simply would not make sense or work at anywhere close to 1A.
Ah, OK, understand now re "switched pump, thanks.

Agree this unit has more reporting & this can show up issues.
I was thinking of the "one wire" type active balancers which are "blind" & have little/no reporting.
Looks like the unit here does a lot more.
ajw22 likes this post
Running off solar, DIY & electronics fan :-)
Reply
#9
There are a few reviews out there. Here is a YT that leverages one per pack: https://www.youtube.com/watch?v=YxkGE3QwW8A
They appear to work great, there are some versions that support CAN bus.
Reply
#10
The balancer you list in the OP is an active balancer, they operate by transferring charge from the highest cell, to the large onboard capacitors, once the capacitor is full they then transfer charge to the lowest cells.

The do work, they are configurable but they are VERY slow at balancing large packs, as they only manage 1 cell at a time and only the amount that the capacitor can hold.

From memory a full charge->discharge cycle of the capacitor was almost 2 minutes.

So far I have not been able to justify the money to see if a 10A version is that much better.

Side note: These balancers require 40-100v power source to operate, if your pack is less than this you require a boost converter.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)