New Active balancer

[RCinFLA]

If you have not already seen, there is a new BT active balancer that is DC-DC converter to supercap storage similar to the much more expensive unit that has been on market for some time. It allows balancing to be restricted to near top end of charging so it avoids most of the cell overvoltage difference with load current problems in flat portion of discharge curve that can cause balancing in wrong direction.

11.39US $ 24% OFF|Neey 4a Smart Active Balancer 3s 4s 5s 6s 7s 8s 14s 16s 20s 21s 22s 24s Lifepo4 / Lipo/ Lto Battery Energy Equalization - Battery Accessories & Charger Accessories - AliExpress

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[John Frum]

Andy did a review

Needs a power supply for 10s or under.

 

[coalfield]

Andy did a review

Needs a power supply for 10s or under.

any recommendations for power supply with this?

 

[John Frum]

any recommendations for power supply with this?

Can't say.
I've no experience with balancers or BMSs that require an external power supply.
I guess you would use a dc2dc boost converter.
I've had such bad luck with cheap dc2dc converters that I find the usage model a bit sketchy.
Did you see the subsequent review of the JK BMS?
Except for the dependency on an external power supply, it looks pretty good.
If you pursue the idea please share you knowledge.

 

[noenegdod]

any recommendations for power supply with this?

I just ordered this for my 12v pack. I am only going to be using it occasionally so I am just going to make a small 30v battery to operate it.

 

[RCinFLA]

any recommendations for power supply with this?

The balancer needs a 30v to 100v dc supply. Only needs about 25 mA max. For 16s battery array it can be powered from battery stack. 4s or 8s needs a separate power supply. You could get a small DC-DC boost converter to run from 4s or 8s batteries.

 

[coalfield]

Very tempted to get this I have to say, although I am yet to even get batteries, let alone a charger!

I also messaged the seller to see if they has an iOS app, apparently in 10 days which seems very specific and would not be holding out much hope for. Need to dig out an old android phone if I want to use this

 

[nebulight]

I emailed them from their github page. Looks like they will have a 12v/24v option soon. May want to wait for that instead of wiring up an external power supply.

 

[fafrd]

If you have not already seen, there is a new BT active balancer that is DC-DC converter to supercap storage similar to the much more expensive unit that has been on market for some time. It allows balancing to be restricted to near top end of charging so it avoids most of the cell overvoltage difference with load current problems in flat portion of discharge curve that can cause balancing in wrong direction.

11.39US $ 24% OFF|Neey 4a Smart Active Balancer 3s 4s 5s 6s 7s 8s 14s 16s 20s 21s 22s 24s Lifepo4 / Lipo/ Lto Battery Energy Equalization - Battery Accessories & Charger Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

$101 seems very pricey to me. I picked up one of these Heltec Active Balancers for less than a third that much and have been very happy with it: https://www.amazon.com/Heltec-Equal...cphy=9032080&hvtargid=pla-1196266193651&psc=1

 

[coalfield]

$101 seems very pricey to me. I picked up one of these Heltec Active Balancers for less than a third that much and have been very happy with it: https://www.amazon.com/Heltec-Equal...cphy=9032080&hvtargid=pla-1196266193651&psc=1

Watching the video there seem to be some potential issues with this one, I am a n00b so cant really comment, but they certainly look to be apples and pears.

 

[fafrd]

Watching the video there seem to be some potential issues with this one, I am a n00b so cant really comment, but they certainly look to be apples and pears.

What ‘video’ are you referring to?

The Heltec is a very simple design. The only issue is how long the capacitors will last (unknown for me at this stage).

 

[Roswell Bob]

What ‘video’ are you referring to?

The Heltec is a very simple design. The only issue is how long the capacitors will last (unknown for me at this stage).

Can you give us a short blurb describing how this unit works? All I see is an array of capacitors. What is the principal by which it operates. Thank you.

 

[Horsefly]

I don't know if this company and JK are related, but the JK BMS also seems like a really good BMS, as long as you have a 16S 48V system. Otherwise you have to have some very inefficient boost converter to provide the power, which makes it impractical for 4S and 8S packs.

 

[fafrd]

Can you give us a short blurb describing how this unit works? All I see is an array of capacitors. What is the principal by which it operates. Thank you.

I’m not certain but can guess (EE background):

1/ Charge a capacitor in parallel from each cell (probably all three capacitors in parallel, not sure).

2/ Now disconnect each capacitor from its cell.

3/ Now short all of the capacitors together, settling to average of cell voltages (capacitors associated with any cells above average voltage will decrease, capacitors associated with any cells below average voltage will increase, capacitors associated with any cells exactly at average voltage will see no change).

4/ Open the connection between capacitors so that each capacitor (or bank of 3) is isolated from the others.

5/ Now reconnect each capacitor (or bank of 3) to its corresponding cell again which will inject some charge into all low cells and will remove some charge from all high cells (and will leave cells at average voltage unchanged).

Now go back to step 2 and repeat that cycle endlessly…

Once all cells are at the average voltage (balanced) there will no longer be any charge transferring into or out of the capacitor bank…

 

[fafrd]

I don't know if this company and JK are related, but the JK BMS also seems like a really good BMS, as long as you have a 16S 48V system. Otherwise you have to have some very inefficient boost converter to provide the power, which makes it impractical for 4S and 8S packs.

Is this thread about BMSs or Active Balancers.

Heltec BMSs do seem to be the same as JK BMSs (apparently share specs as well as software / firmware).

Heltec’s Smart BMSes below 16S/48V do require a ‘boost’ from 24V or 12V, but theirc’dumb’ BMSs can be powered directly by an 8S or 4S battery…

 

[Horsefly]

Is this thread about BMSs or Active Balancers.

I was just commenting that this looks like a good active balancer, but it appears to suffer from the same limitation as the JK BMS that makes it impractical for use on 8S or 4S packs.

 

[fafrd]

I was just commenting that this looks like a good active balancer, but it appears to suffer from the same limitation as the JK BMS that makes it impractical for use on 8S or 4S packs.

Well I’m powering my 8S Heltec Active Balancer directly off of my 8S battery (as I type this, in fact).

 

[Horsefly]

Well I’m powering my 8S Heltec Active Balancer directly off of my 8S battery (as I type this, in fact).

Right. I have 3 Heltec Active Balancers. They are great, but don't have some of the features that the subject of this thread has: Larger balance current, and configuration via BT app.

Just to be clear: I never said anything about Heltec so I'm not sure how we got here.

 

[fafrd]

Right. I have 3 Heltec Active Balancers. They are great, but don't have some of the features that the subject of this thread has: Larger balance current, and configuration via BT app.

Just to be clear: I never said anything about Heltec so I'm not sure how we got here.

It’s my bad - I confused you with ‘coalfield’ who referred to the ‘issues’ from the video in the Heltec Active Balancer Video in the Amazon page I linked to…

I’m using a Heltec (‘dumb’) BMS and a Heltec Active Balancer and for sure, their ‘Smart’ BMS including Active Balance off additional features (but suffer from the need of ‘boost’ from 24V and 12V that’s been referred to).

Heltec and JK seem to be the same company or closely related (same products, common software) and my biggest gripe with the BMS I have is the limited charge current. It will discharge up to 300A but max charge current is 100A…

[PS. What current are you getting from your Active Balancer(s)?

They claim 1A @ 100mV of deltaV up to a maximum of 5A (presumably requiring a deltaV of 500mV).]

 

[Horsefly]

[PS. What current are you getting from your Active Balancer(s)?

They claim 1A @ 100mV of deltaV up to a maximum of 5A (presumably requiring a deltaV of 500mV).]

I've checked it many times, but never with a 500mV delta. I think with a 200mV delta one time I got something between 1.5A and 2A. I only know that it has worked well to get the diff down to 1 or 2 mV at rest.