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So why buy an additional balancer if active balancing is part of bms? This turned into waste of time

D71

D71

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Why buy an active balancer if active balancing is built-in as part of the bms?

example:

www.currentconnected.com

JBD BMS 24V/100A (8s) | Current Connected

The JBD BMS is designed to protect your LiFePO4 batteries and cells, ensuring maximum lifespan and performance of your energy system!
www.currentconnected.com www.currentconnected.com

Support/Downloads – Overkill Solar

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VS

Add on balancers examples


help me out here haha bart simpson laugh.
 

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D71 said:
Why buy an active balancer if active balancing is built-in as part of the bms?
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Because the one in the BMS is usually crap. Most built ins usually only balance in the milliamp range where an external one may do amps (thus faster).
 
I don't think it's a good idea to have multiple things trying to balance your pack.

I would shut off balancing in the BMS if using an external active balancer. If you have active balancing built into the BMS an external one would be overkill.
 
Bob B said:
If you have active balancing built into the BMS an external one would be overkill.
Click to expand...

I will have to disagree. I have always had much better balancing with an external one, often getting down to .001v Is that precision needed? Maybe not, but an external balancer is cheap.
 
Texas-Mark said:
Because the one in the BMS is usually crap. Most built ins usually only balance in the milliamp range where an external one may do amps (thus faster).
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The battery is recommended to be top balanced… the himassi show up 0 percent soc. I doubt they even check anything .
 
Texas-Mark said:
I will have to disagree. I have always had much better balancing with an external one, often getting down to .001v Is that precision needed? Maybe not, but an external balancer is cheap.
Click to expand...
I didn't say not to use an external one .... just don't have the one in the BMS trying to balance at the same time.
 
Texas-Mark said:
I will have to disagree. I have always had much better balancing with an external one, often getting down to .001v Is that precision needed? Maybe not, but an external balancer is cheap.
Click to expand...
When you use the external balancer it only uses + and - terminals on sealed battery the bms uses the plug for each cell extternal balances whole battery against whole battery
 

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The add on balancers you linked to are for balancing multiple batteries in series. The internal BMS only balances the cells inside the battery. It doesn't care what the batteries voltage is in relation to another battery in your series battery set.

The external balancers for 12v batteries in series will help to even out the voltage between the batteries a bit if they have any difference in voltage. Depending on the quality of the internal BMS's and how balanced the cells are internally, you will have frequent HV / LV disconnects of individual batteries in series when charging/discharging them in series if they aren't very well balanced internally. The 12v balancer helps out a bit by taking some of the overage from one of the 12v batteries and putting into the other lower voltage batteries in the series.

I've found it helpful with my 12v lifepo4 batteries in series, but I'm using pretty crappy 12v lifepo4 batteries.
 
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cs1234 said:
The add on balancers you linked to are for balancing multiple batteries in series. The internal BMS only balances the cells inside the battery. It doesn't care what the batteries voltage is in relation to another battery in your series battery set.

The external balancers for 12v batteries in series will help to even out the voltage between the batteries a bit if they have any difference in voltage. Depending on the quality of the internal BMS's and how balanced the cells are internally, you will have frequent HV / LV disconnects of individual batteries in series when charging/discharging them in series if they aren't very well balanced internally. The 12v balancer helps out a bit by taking some of the overage from one of the 12v batteries and putting into the other lower voltage batteries in the series.

I've found it helpful with my 12v lifepo4 batteries in series, but I'm using pretty crappy 12v lifepo4 batteries.
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You confirm basically what I stated external battery to battery
 
Internal balancing often occurs around the 3.5 volt range according to some various documentation but can vary for obvious reason for cells and bms control with software - flashed firmware.
 
D71 said:
You confirm basically what I stated external battery to battery
Click to expand...

You are the original poster of this thread. I'm confused. I thought you were saying the external 12v balancers for 12v batteries in series aren't serving any purpose because there is an internal BMS.

Are you for or against the external 12v balancers?
 
cs1234 said:
You are the original poster of this thread. I'm confused. I thought you were saying the external 12v balancers for 12v batteries in series aren't serving any purpose because there is an internal BMS.

Are you for or against the external 12v balancers?
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quote myself

”Why buy an active balancer if active balancing is built-in as part of the bms?”
”help me out here haha bart simpson laugh.”

the post you replied to states as much as you repeated. This is a devil’s advocate sort of thing for everyone to learn. It is not intended to start a fight. Or name calling or any other juvenile actions that often happens on forums. Sometimes new ppl don’t know the right questions to ask or that the bms actually perorms a active balancerr role. As far as that goes some balancers just drain the power away with bleed resistors. So…
 
D71 said:
quote myself

”Why buy an active balancer if active balancing is built-in as part of the bms?”
”help me out here haha bart simpson laugh.”

the post you replied to states as much as you repeated. This is a devil’s advocate sort of thing for everyone to learn. It is not intended to start a fight. Or name calling or any other juvenile actions that often happens on forums. Sometimes new ppl don’t know the right questions to ask or that the bms actually perorms a active balancerr role. As far as that goes some balancers just drain the power away with bleed resistors. So…
Click to expand...
I think the confusion is with some of the products you linked in post 1 .... a couple of them are battery equalizers ... not active individual cell balancers.
 
In old days when we had carbon batteries before new alkaline for flash lights some ppl would only replace 1of the 2 cells with a new battery so once you applied the load of the flash light being on then the weak cell and the new cell would try to normalize and it would drag juice from the new cell to the weak cell that was not replaced. We were then taught to just put 2 new cells in vs just 1 new cell.… for the flash light.
 
Bob B said:
I think the confusion is with some of the products you linked in post 1 .... a couple of them are battery equalizers ... not active individual cell balancers.
Click to expand...
And you win the prize for misleading advertising
 

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Bob B said:
I think the confusion is with some of the products you linked in post 1 .... a couple of them are battery equalizers ... not active individual cell balancers.
Click to expand...

Yes, I thought we were talking about cell balancing. But, if taking about "pack" balancers, then that is different. But they still serve a purpose that the internal BMS cell balancer does not.
 
I have that very same 4s 12v for 48v active balancer. It's helping keep my himassi and other lifepo4 battery brand Frankenstein batteries in series stay equal"ish". Considering the relatively flat voltage curve on lifepo4 it's not perfect, but it's doing wonders compared to before with no active balancer on it.
 
sunshine_eggo said:
How is that misleading advertising? If you have poor reading comprehension, it's on you.

If one is using a 4S 12V for 48V, an active balancer as linked has value to keep the individual 12V elements at the same voltage.
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It states right on it equalizer as bob pointed out Don’t be insulting…. Don’t do it
 
Clearly the makers/sellers of "Mazava HC02 LED Tube Display Battery Equalizer Voltage Regulator 4pcs Batteries Active Balancer 4S Connected in Series for 48V Battery System Solar Power System Extend Battery Life" aren't native English speakers. They also seem to be using key words to try to get more views. Considering the target audience on the internet, it's not an inherently bad idea.
 
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