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Active balancing boards

I just found this
https://s.click.aliexpress.com/e/UWolwyK

According to the specs this board start to balance the cells as soon as they get out of balance. So even if your board is not on the charger it will always be balancing.

What’s your thoughts about it?

Calling the bms master @b264 as well, your opinion is highly appreciated :wink:

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I think unless this has an on/off feature for the balance board it might screw with your bms while charging the pack. Or it might take longer to charge because I’m pretty sure the bms does one series at a time? I’m interested in this though.

I think the idea is to use these instead of a BMS. This is what some builders are doing, tho I have never personally used one I am interested.

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I see, so charge leads directly to the battery terminals and one of these balance boards to handle balance. Basically a discharge bms without the bulk. Kinda sounds to good to be true but I’m not the type to remain ignorant in the face of knowledge.

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The idea is to balance inbetween the cells, so more or less a energy transfer from the cell with higher voltage to a cell with lower voltage and this up to 1.2A which would be way faster than a bms. You could use this device in addition to a bms or just without bms. The balancer itself does not provide any cut off features though

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It kind of does :). Im waiting on some feedback, but if all is good I’m gonna try it out.

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I might try it for giggles. Just wait some feedback from the supplier as I can see only a 13s option which would fit and I’m not sure if it’s possible to use it as 12s.
Even if it’s just half of what it promised it would be nice to have a device connected to your balance wires which 24/7 enables some kind of floating balancing between the serial packs (like cells in parallel do by there own). That would mean that your pack get balanced by just sitting around. As soon as the cells are in the balance range the module just switch off.

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Getting one to test too. Especially since my tiny 13s BMS doesn’t balance and I’m too lazy to solder on a balance board.

Try this us ebay link. The description says it can be used for 2-13S.

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would this not put extra strain on the cells as you are riding? your esc will be pulling amps and then this thing will be trying to charge/discharge 10/12 group of cells at the same time. sounds like something could easily go wrong.

edit: can you even charge a p group as it is being discharged?

edit2: at 12s, thats a possible 144 pathways. double that for charge/dischrarge. Seems to go against the KISS principle.

I am not going to promote the smart bms again, but you can set always balance on. So when off the groups goes below the delta V. It will start to balance.

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whats the bms yo?

I have a smart bms as well but it takes ages to get cells balanced, plus the size factor would be way smaller with the active balance board.

Manufacture: https://www.lithiumbatterypcb.com/product-instructionev-battery-pcb-boardev-battery-pcb-board/ev-battery-pcb-board/smart-bms-of-power-battery/

But I always buy them on aliexpress. Much faster to handle everything

As i undetstood it can’t handle all cells in one. I need to get more information about how it works though. I think it just takes the highest cell and spread it on the other cells.

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Yeah it takes a long time, but if all off your cells you use are the same aged, there is a minimal delta v.

Indeed but they you need also a bms

interesting. I was researching these about a year ago. back then the app was horrendous. can you give me the ali express link pretty please :slight_smile:

I searched for smartbms but its all confusing lol

yeah would be good. seems like it could potentially be unnecessarily complicated. let us know what you find.

Why?
If it works as advertised and you charge with let’s say 3-4a you pack should theoretically be do good balanced that the charger cut off and all cells are at 4.2V. Not saying it can replace a discharge bms, but a charge only bms maybe

The app on IOS is absolutely beautiful. It is a project from a guy on github.
When I bougth the app it was around 5 euro. Now the app is free if you want to check your bms, writing settings is a in app upgrade off 1 euro i think. Also Apple watch support and more coming soon.

Haha just look for such a model with the correct s count.

I have found that not all settings can be adjusted in the app. some are only possible by linking with the PC. The small black box can be purchased for this purpose.

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I think about a way of fast balancing lipos as well, just as example. Lipos drift more strong than LiIon in parallel packs from my experience. So for example I could imagine a combination of the balance module with a smart bms as external cheap Hobby balance charger option. You set the cut off at 4.21V on the smart bms and after your charger switched off it takes another 15min and all your cells are balanced at 4.17V