How do you use a new battery?

[Gionnirocket]

Ahh. Maybe that’s why I always see 54.3v after charger indicates charging is complete.

Yes...very common.

 

[m@Robertson]

I'm speaking about built in batteries on bikes like Aventon, Ride1Up, Biktrix and my Zen etc....

Then I don't have a clue as to what they have inside them. The more I see ebike manufacturers go out of business, the more I pat myself on the back for having nothing to do with a bike that needs a specific factory-spec battery pack that may no longer be in production. Black-boxing the batteries and their internal specs is something other people can put up with. Same goes for a simple green-light charger.

I've always stuck to higher end USA manufacturers. Although I do know EM3EV has balancing BMS'. Theirs are Bluetooth and as a result they have a tiny parasitic drain on the pack, which is why I never would use a bluetooth BMS. Interestingly that particular BMS was known to be almost unique in that it would start balancing well below the usual 98%+ that most BMS' operate at. My Luna Wolf packs also have balancing BMS' inside (those were custom to Luna for that pack) as my 2015 Luna 25R pack has one as well. All of my Bicycle Motor Works packs have Balancing BMS', both the off-the-shelf packs they sell retail and the custom ones. And the custom triangle Hi-C Battery made for me, same deal.

Curious.. do you have the spec sheet on your Battery/BMS?

Nobody provides those. Not even on the packs I have had custom built, where I have current rates in the 70a+ continuous output range hence the need for a custom. My most recent is actually 100a continuous simply because there was nothing else available for a few months and I didn't want to wait that long to get the pack built. But I do make a point of finding out at what point the BMS will start balancing. Come to think of it EM3EV used to provide BMS specs, but its been years since I have paid any attention to them so maybe not anymore.

I believe that is topping off.... Not balancing.

Well, with a balancing BMS I can't see how it would be anything but balancing.

A few months ago I was passed along screenshots of a conversation from another member in which a well known 'import' battery manufacturer both admitted to producing packs without balancers inside, and also tried to justify that by saying because they used quality/genuine cells, that a balancer wasn't necessary since the cells were pretty closely balanced already thanks to the brand name in use (Samsung). This was an asinine excuse. There is still variance in those cells and its enough that - over time - a balance charge is a benefit. And its telling the manufacturer doesn't say a word about this unless pressed, and then only does so privately.

I do agree a lot of people THINK they have a balancing BMS. and they don't. One more reason a battery is the thing you spend real money on, and never buy a bargain.

 

[m@Robertson]

No... my understanding is this. When current is put in or out the battery..it surges or sags respectively. If left alone it will settle lower or higher respectively. So on a charge it will reach termination voltage, 54.6v...and then settle lower once current drops. Then the charger will bring it back up to termination voltage again and again until it's settles in at the full termination voltage. Or if matched well, the charger will trickle in such a low current that the settling in is negligible.
If it's a quality battery with matched internal resistance between all the cells..no balancing is done or necessary.

But to add to that, if a given individual cell is not at a matching voltage with the other cells in its cell group, a balancing BMS will sense this and apportion a bit of current over to it to bring that cell up to match the other cells in the (parallel) group. The power has to come from somewhere and that somewhere is the other cell(s) in the same parallel group. the charger then senses this teeny drop and the tiny blip of 0.1a or so from the charger will feed the pack a bit, and the process repeats until its over. Its the same action as 'topping up' (which is the natural final stage of CV Mode) on the charger side, but for a different reason.

The internet will tell you that balancing takes 6 to 12 hours but from what I've seen its a lot more like 1 or 2 even on a 35ah pack. But watching a pack balance is like watching paint dry so nobody does it to find out for sure.

 

[Gionnirocket]

Then I don't have a clue as to what they have inside them. The more I see ebike manufacturers go out of business, the more I pat myself on the back for having nothing to do with a bike that needs a specific factory-spec battery pack that may no longer be in production. Black-boxing the batteries and their internal specs is something other people can put up with. Same goes for a simple green-light charger.

I've always stuck to higher end USA manufacturers. Although I do know EM3EV has balancing BMS'. Theirs are Bluetooth and as a result they have a tiny parasitic drain on the pack, which is why I never would use a bluetooth BMS. Interestingly that particular BMS was known to be almost unique in that it would start balancing well below the usual 98%+ that most BMS' operate at. My Luna Wolf packs also have balancing BMS' inside (those were custom to Luna for that pack) as my 2015 Luna 25R pack has one as well. All of my Bicycle Motor Works packs have Balancing BMS', both the off-the-shelf packs they sell retail and the custom ones. And the custom triangle Hi-C Battery made for me, same deal.

Nobody provides those. Not even on the packs I have had custom built, where I have current rates in the 70a+ continuous output range hence the need for a custom. My most recent is actually 100a continuous simply because there was nothing else available for a few months and I didn't want to wait that long to get the pack built. But I do make a point of finding out at what point the BMS will start balancing. Come to think of it EM3EV used to provide BMS specs, but its been years since I have paid any attention to them so maybe not anymore.

Well, with a balancing BMS I can't see how it would be anything but balancing.

A few months ago I was passed along screenshots of a conversation from another member in which a well known 'import' battery manufacturer both admitted to producing packs without balancers inside, and also tried to justify that by saying because they used quality/genuine cells, that a balancer wasn't necessary since the cells were pretty closely balanced already thanks to the brand name in use (Samsung). This was an asinine excuse. There is still variance in those cells and its enough that - over time - a balance charge is a benefit. And its telling the manufacturer doesn't say a word about this unless pressed, and then only does so privately.

I do agree a lot of people THINK they have a balancing BMS. and they don't. One more reason a battery is the thing you spend real money on, and never buy a bargain.

Thanks.
I totally understand where you are coming from and somewhat agree on its necessity... but you have to admit that your level of DIY is not within the capabilities of most and is far from the majority of ebike batteries out there.
For me I wanted a low step FS with a neat integrated battery and an programmable motor so the Zen Ultra fit my needs perfectly.
I'm not speaking in absolutes as the technology is ever evolving.... But the way I understand it you can either have Passive or Active Balancing. That's why I asked for a spec sheet.
Active balancing is typically reserved for much larger set ups as the circuitry and cost are not easily scaled down.
Passive balancing found in eBike batteries uses resistors to burn off excess current as the cells approach full so that they don't overcharge while the less than continue to charge. Hence my comment about heat and why it's argued that it can be counterproductive and not always necessary if quality matched cells are used. And matched cells doesn't only mean the internal resistance.. but using the same manufacturer lot so that chemistry and production variables are minimal.
To address some of what you said about the balancing process... this is my understanding.
Any cells connected in parallel naturally balance SOC between themselves and on there own.. and once permanently connected in parallel act as a single cell. The BMS has no function here.
Then cells (groups) in series balance as I described above with the addition of current burn off resistors.
What you are describing sounds more like active balancing.. and I'm not saying that it's not possible but I haven't seen any documents showing this and I'm further assuming that the price would be prohibitive.
I believe EM3EV uses a Daly BMS w/Bluetooth and is passive.
When I had this discussion with Jenny Mao before purchasing one of her Sanyo batteries for my DIY build, she did provide me with BMS white paper but also discouraged me from going with the Balance option for the above reason... which I did.
This said in my very recent brief discussion with Ravi, he did say Zen is using a balance BMS. I could be wrong but I believe discussions on this subject with him quite a while ago it leaned towards not necessary with quality cells... But I don't want to misquote him and honestly my mind is mush lately with my ever ongoing situation so I wouldn't be surprised if I am mistaken. But it is part of the reason why I have this understanding.
He's going to give me a call so I can fully understand the Zen architecture once he has a free moment.

Since you're a good customer, perhaps you can request a little more detail from your vendors if white paper is verboten?
If only this information was in government classified documents.. we could just check the bathroom at Mar a Lago

But to add to that, if a given individual cell is not at a matching voltage with the other cells in its cell group, a balancing BMS will sense this and apportion a bit of current over to it to bring that cell up to match the other cells in the (parallel) group. The power has to come from somewhere and that somewhere is the other cell(s) in the same parallel group. the charger then senses this teeny drop and the tiny blip of 0.1a or so from the charger will feed the pack a bit, and the process repeats until its over. Its the same action as 'topping up' (which is the natural final stage of CV Mode) on the charger side, but for a different reason.

The internet will tell you that balancing takes 6 to 12 hours but from what I've seen its a lot more like 1 or 2 even on a 35ah pack. But watching a pack balance is like watching paint dry so nobody does it to find out for sure.

Again I don't think that's how it works. You're talking about individual cell monitoring which would require cell isolation and a whole lot of circuitry to facilitate.
I believe it's as I mentioned earlier in that parallel cells self balance as far as SOC is concerned and the balancing in ebike batteries when implemented is addressed in the series part of the circuit and the balancing of the parallel cell groups.

I'm more than happy to learn here so any actual documentation would be helpful.

 

[PedalUma]

I highly respect each of the informative commenters here and have an off topic, maybe, endnote. I spent several hours today at an all electric bike shop, the owner has three criteria for bikes that he carries: 1) Quality, 2) Hydro, 3) UL batteries. I am not sure if UL is really a real thing. I rode three Specialized bikes today, a Como with an Enviolo belt and a belt driven motor, a Como SL with a direct drive geared motor to a belt Alfine 11, and a Vato SL direct drive chain to 11 cassette. The Vato was fastest by far with crisp shifts but loud. I passed a roddie on a climb at 32 Mph. The Como Enviolo was the most quiet and smooth. But the shifting requires removing the right hand from the grip and that represents a loss of control when in action situations. Last week I purchased some UL certified zip ties in a 50 pack for $7. Then non-UL are a buck-twenty for 50. And I cannot tell the difference! Is UL really a thang when it comes to batteries? Or is it like a purchased Good House Keeping seal of approval, hype?

​

 

[Gionnirocket]

I highly respect each of the informative commenters here and have an off topic, maybe, endnote. I spent several hours today at an all electric bike shop, the owner has three criteria for bikes that he carries: 1) Quality, 2) Hydro, 3) UL batteries. I am not sure if UL is really a real thing. I rode three Specialized bikes today, a Como with an Enviolo belt and a belt driven motor, a Como SL with a direct drive geared motor to a belt Alfine 11, and a Vato SL direct drive chain to 11 cassette. The Vato was fastest by far with crisp shifts but loud. I passed a roddie on a climb at 32 Mph. The Como Enviolo was the most quiet and smooth. But the shifting requires removing the right hand from the grip and that represents a loss of control when in action situations. Last week I purchased some UL certified zip ties in a 50 pack for $7. Then non-UL are a buck-twenty for 50. And I cannot tell the difference! Is UL really a thang when it comes to batteries? Or is it like a purchased Good House Keeping seal of approval, hype?

​

It's a thing... and typically a good thing.
But that doesn't stop someone from creating a quality product and not going through the testing/certification process.
I was doing a job for a fortune 500 company in Greenwich CT and they had purchased some really beautiful pendant fixtures that were finished off with hand blown Murano glass shades. They looked like glass slippers and all the wiring and hardware was top shelf. If I remember correctly we had installed about 100 of these in their employee cafe. When the inspector came through he had us remove them all... No UL label. Getting them certified was going to be too costly and time consuming and we ended up installing some ho_hum Progress Lighting fixtures that were garbage quality when compared to the originally spec'd ones. Bad on the architect and electrical engineer as they should have known better, especially when dealing with the Greenwich building department. If the inspector wanted to he could have passed it as he has final discretion.. but I guess the proper grease wasn't applied.

 

[m@Robertson]

you have to admit that your level of DIY is not within the capabilities of most and is far from the majority of ebike batteries out there. But to be realistic about it, most people just want to write a check and not know anything.

Oh absolutely. Having this level of personal control over the process is why I do it. The battery. The charger. The components like the brakes, drivetrain... On and on. I certainly am not saving any money at least not the way I do it.

Active balancing is typically reserved for much larger set ups as the circuitry and cost are not easily scaled down.
Passive balancing found in eBike batteries uses resistors to burn off excess current as the cells approach full so that they don't overcharge while the less than continue to charge. Hence my comment about heat and why it's argued that it can be counterproductive and not always necessary if quality matched cells are used. And matched cells doesn't only mean the internal resistance.. but using the same manufacturer lot so that chemistry and production variables are minimal.

I expect all my setups are passive balancing, but honestly I have no idea. I didn't dig that deep when I was spec'ing the custom packs other than to require balancing, find out the balancing point and specify exactly how much continuous output I had to have. In hindsight I should have gone further but really, it only would have done me any good in a forum conversation as practically speaking I've been doing fine not knowing any better. And I still get great performance out of my very first pack bought in 2015, which was charged twice daily for years when it was in my daily driver and is now semi-retired. So whatever I am doing isn't hurting anything, at worst.

The arguments against passive balancing can I think be addressed successfully by
1. First building the pack with reasonably well-matched cells. No more than using the same production lot and a resistance test.
2. Do the 'six times' thing I mentioned when I first posted here (I got that from Eric Hicks @ Luna, btw).
3. Charge at low current levels. Everyone wants fast charging but it throws all sorts of things out of whack, and balancing the pack more effectively can be added to that, I suppose, although I never really gave that much thought when making my decision to use slow levels of charging. I do my balance charging with my Satiator (since my onboard charger is fixed at 3.0a) and its set to 0.5a. On packs meant to pump out up to 70a continuous I don't think the blips that occur from burning off excess charge can be worried about by comparison. Especially when you do a reality check and note that 100% charges are only done once a month on a pack charged probably daily

To address some of what you said about the balancing process... this is my understanding.

I really did a s*it job of explaining that. Of course, the BMS only connects via a single wire to each cell group, and the imbalance detected is for one group versus the other groups in the pack. The individual cells within an individual group are the culprits, and become the beneficiaries of the balancing current that can flow into them, but its monitored and fed at the group level.

When I had this discussion with Jenny Mao before purchasing one of her Sanyo batteries for my DIY build, she did provide me with BMS white paper but also discouraged me from going with the Balance option for the above reason... which I did.

Honestly I think thats terrible advice. The pack is a living thing and its needs can change over time and use/abuse. Plus, relying on a production lot to have minimal variance is putting a lot more trust in the cell manufacturer than I ever would, regardless of how good they are known to be. My 17.5ah Luna pack from 2015 has received, last time I checked, over 2000 charge cycles (not complete cycles of course). Can I prove the balancing contributed to longer life? No. But for the pittance the option costs versus the cost of the entire pack, I want every advantage, and a charge regimen and parts list that yields that kind of pack life is not something I think can be argued against. In fact, the only pack I have ever had that has gone to pot is one that I thought was being built as a custom job, and it was... but it turned out the seller was silently outsourcing their packs to UPP ...

This said in my very recent brief discussion with Ravi, he did say Zen is using a balance BMS. I could be wrong but I believe discussions on this subject with him quite a while ago it leaned towards not necessary with quality cells... But I don't want to misquote him and honestly my mind is mush lately with my ever ongoing situation so I wouldn't be surprised if I am mistaken. But it is part of the reason why I have this understanding.

I think the crucial point is 'necessary' versus 'beneficial'. For something like a battery pack that costs so much, if you are willing to go the extra mile to take care of it, and know enough to do that, a blancing bms is going to help that pack live longer.

Since you're a good customer, perhaps you can request a little more detail from your vendors if white paper is verboten?

I'm pretty much out of the game at this point. The last battery I had built was in late 2022 for my white Bullitt. Before that, Luna graciously sold me a Wolf pack as a single rather than only via a BBSHD kit since I had bought so much from them in the past. That was I think 2021. In years before that... yeah I was loading up. But I'm not building anymore. Just tinkering with what I have, and riding them into the ground.