Active balancing boards

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

So, if there is a voltage difference between the cells it means that some off the groups have less capacity then the others.

When you are charging the whole packs, the groups with less capacity will faster hit the max voltage.

The current you will go charging will be bigger then the current the balance board can handel to correct the voltage from each cell.
So you will slowly overcharge some cells.
A balance circuit in the bms will charge until one off those cells are at 4.2v when one off the cells hit that voltage, the bms will start to discharge the cell to the higest voltage from one off the other cells.
Repeating this entire progress over time reduces the difference between the cell voltage.

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But I think that when you place the balance plug from the balancer parallel over the balance plug from the bms. And you charge your cells through the BMS. You will be fine.

Due this you can boost up the balance capabilities

Why it cost so little when regular bms (without BT) are way more expensive?

Mass production + easy to change the cell count by soldering a bridge on the balance pins and set it in the windows tool.

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This is basically the same thing as a charge-only BMS, except without the safety features that would cut off charging.

So if your charger messed up and went too high, this would not stop it from lighting the battery on fire.

I’ve also eyeballed these and thought about it, but never used them. I think a small charge-only BMS is much better as it gives you redundant safety features (in the charger and in the battery). That way if your charger failed [in a certain way] it wouldn’t be an automatic fire.

And if you wire your ESC around the BMS straight to the battery in a standard esk8 “bypassed” configuration, your ESC could still overcharge (like on a long hill braking on full charge) without cutting off brakes, but the charge port can’t overcharge.

Im using one of this BMS and its great. Honestly wouldn’t consider using anything else for future builds.

Now if only someone would write some code so that we could interface the uart into the vesc and relay all the data into metr :slight_smile:

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There’s a new smart BMS on the block that supports a wider range of things than the LTT power ones although it does appear to be similar.

I ordered one for science as it looks interesting but 400Ma balance current is more than double of what most BMS’s support!

Will share my findings!

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:sweat_smile: it’s the same company which sell the Balance Board :thinking:. Unfortunately the information I fount on Ali are a bit rare and some don’t make sense for me. Like you can set balance current from 0-200mA but may 400mA…what does it mean? Same with discharge, can set from 40-80A but may 255A. Hold us up to date how things are going !

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As i said there is no cut off protection, but there people running no bms at all as well, so that is definitely a way up the game, plus…I think you said all by your own in your comment before:

:tipping_hand_man:

The other thing is that shit can happen with a bms as well. What about the cases where the d140 didn’t balance the first cell group and fucked up not only one pack with it.

What i don’t like in the usual bms as well as in this balance board is that you just don’t see the actual individual cell pack voltage. If there is a bigger drift in one group you will only see it with a smart bms or if you measure your pack with a multimeter from time to time oooor when it’s anyway too late and your bms cut off or you lose power due to one p group being totally off.

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I assumed it’s for the 40 amp vs the 80/100 amp version.

But yes the documentation is very questionable lol.

But no pictures of the app have me kinda worried though lol.

I would just ask the company via pm. They came back to my questions after just 5min yesterday.

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Haha ohhh I considered it but decided to say fuck it and just do it anyway. I mean there aren’t even dimensions but I’ll make it work somehow :joy:

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Has anyone used this Bestech balance board?
it sounds like the perfect board for charge only builds (if you trust your charger).

Thats no active balancing board, more like a bms without protection, so slightly offtopic here :wink:

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@BillGordon pointed me here…

Do I need to start a new topic?

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saw came here because if the title of the thread. Thought i would find more “active balancing boards” like this :

sadly not :frowning:

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Yup, my mistake.

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Yes, please, start one, I’d be highly interested in what others think as I can’t fit a regular charge only in my board, but this one might fit on top of the cells.

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These active balance/smart bluetooth BMS are interesting. Not crazy expensive or huge for their power ratings.

not dead link:
https://www.aliexpress.com/i/33024045846.html