HELTEC 10A Active Balancer. Great for large capacity batteries. But is it really?

Today, we have the HELTEC Active Balancer with 10A balance current on the workbench. As always here on the channel, we want to go to the extreme and see these 10A of current flowing! I have prepared a 12V test battery with the highest deviation possible to give the balancer the best chance to transfer its maximum of 10A between the cells.
I also compare this balancer with the usual 5A capacitive balancers we have used in the past.

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[markdavidson]

Interested in hearing what Heltec support said about your questions. Thanks for the information, as always!

[teardowndan]

I'm guessing the Heltec balancer is simply an isolated DC-DC converter with four single cell outputs in series. To reach close to 10A output, you may need to have two low cells getting 4.5A each assuming the primary side has sufficiently high current/power limit.

[ryanroberts]

I'm glad I'm not the only one that marks boards like this as "bad" and keeps them anyway after they've been smoked. I might need it later!

[boatelectricaldiy]

The reason to buy this balancer is because you can buy the 24s model and use it from 4s-24s. This gives you one balancer to rule them all. I use an unbranded model because it's cheaper then the Heltec. It has terminals I put my own wires in so they are sized correctly.

[loucinci]

Yes. Follow up video for sure. Thanks for sharing

[danielardelian]

The JK-BMS seems to have the best balancing algorithm. The balancing current does not depend on the difference, the JK-B2A... version can balance with 2 amps even at 20 mV difference and you can set the "Balance Start Volt" to stop it from actually causing more imbalance at cell voltages below 3.45V

[stevenlane]

Yes for the Haltec bms followup please Andy

[ericheydemann]

Wow! Thank you. I have those balancers in my cart and was about to press the buy button.
Standing by awaiting the follow up video

[FutureSystem]

Thanks Andy, great testing again. 👍
I’ll just have to wait for them to return my faulty JK BMS, nothing heard yet. 👎

[excillisbank]

Merci pour ce partage technique et test sur les 2 actives balancers d'HELTEC idée à développer...

[lj]

The Heltec is an isolated design that uses a flyback circuit to transfer energy from one cell to another. I would guess the total current that the balancer can handle is 10A for the entire pack, meaning 2 cells at 5A. You may need a NMC cell to achieve the necessary voltage delta and 10A for a single cell.

[ingmarmaul]

It looks like this new „10A“ balancer provides power the hole time and do not have the problem with charging and discharging the capacitor’s so we even transfer more power within the same time, can you check this.

I like the design it is more failure resistant instead of the capacitor balancer.

[svens.]

Hey Andy, pleased make a Video about the respond. Im very interested what they say about the wrong current measurement

[awesomedee]

Yes. Please make a followup. That is curious from the same manufacturer. My first thinking was those cheap wires you mentioned if there was too much resistance, or if it was based on the Lithium Ion batteries with the higher voltage instead of the LiFeP04 voltages.

[jerry]

I wonder if the balancer just turns off because the cell voltage is below 3.4V. (In the automatic mode).
Great video as always, keep it up.

[fossil]

Andy when you try to measure with the CRO check both ends of the bal leads. i.e. you will be checking lowZ at the cell terminal & what you will see at the bal end may have you thinking!

[inmyimage]

Another vote for testing 2 low cells in the pack as well as how long it takes each balancer to balance the pack and how each affects the charge and discharge cycle, especially with cell 6 and your other weakest cell.
Luck of the draw gave me 2 sets of mismatched cells for a pack from someone who disappeared so I can’t replace them and am likely going to put an active balancer on the pack full time but look for a solution that will only turn it on above 3.4v and below somewhere like 3.25v (need to dig into your test data more to pick better start and stop voltages).
Have Daly BMS’s thanks to Will Prowse’s recommendations for them so don’t have an effective balance function 🥺

[xpatrikpvp]

That is a interesting way to make a active balancer... Maybe thicker cables would help it to reach 10A balancing (Maybe it's already 3.6v at the balancer conector pcb)

[evil]

I dont mind the sleep function idea even tho it doesn’t bring the levels closer than 110mv as you can still turn it on periodically to bring them all into proper balance, if this balancer does indeed balance completely at all as it should, maybe this could be another test.
It was a disappointing demo to say the least, it should have performed according to specs, the cover is a nice touch but not worth the extra $. I would like to hear Heltec’s response to what you have found here and to the bms queries also. Thanks for all ur testing here Andy, its good to see what we can actually expect from these devices ur always testing, than what we may expect when reading the specs. I guess a good formula for buying ‘Chinese’ anything, is expect half or less than the stated information. Good vid & test. Cheers

[dubusonrenovationszarius]

Hi thanks for the previous advice about solar panel fuses, will it be OK if I also put a fuse on the negative wire.