999zip999
100 TW
Give us a link to your motor kit or more info.
Best lifepo4 battery....period.
- Thread starter Electro-Fox
- Start date
arkmundi
10 MW
Electro-Fox
10 W
- Joined
- Sep 26, 2013
- Messages
- 69
teklektik said:EF-
Not to be rude or harsh, but this thread is all over the place - you cannot possibly hope to get meaningful answers...
This is like walking into a bar and shouting - "What's the best pickup to buy?".
- The title itself unequivocally demands LiFe - and yet here you are on page 3 making a buy decision about NMC/NCA cells.
You are going to use a fork bag and won't consider a triangle bag - but now are going to use a triangle bag (goes to cell form factor).
You are concerned about 6% weight difference in NMC/NCA cells but started off with the heaviest/lowest energy density battery (LiFe).
You originally wanted to just jam as much battery as possible into a fixed bag size but now are asking about range.
You haven't given any distance for the commute and say nothing except that it's flat and you pedal a lot (which is easy on power consumption) - don't talk about traffic start/stops (which eat power), and then say you want to pull a trailer (which eats power on starts and hills), and want to ride in the snow (which is incredibly taxing) --- so basically a wide spectrum of use from super light to super heavy with no distance requirements.
And above all else - you didn't want to "go to school in order to buy a battery" and now are asking semi-technical questions, after having discouraged actual technical advice in favor of 'opinions'...
You can be certain that succinct and well-considered answers meeting your exact needs will ensue...
There is nothing wrong with asking noob questions, but you are starting out with critical constraining decisions, then reversing yourself. You may be frustrated by the variety of opinions expressed here - but you pretty much set the stage...
If you really don't want to understand this stuff, then just buy a big-ass battery from Ping or EM3EV (both well respected vendors with completely different offerings) and enjoy whatever it will do for you. Experience will fill in the blanks you don't wish to investigate up front. This generally works okay and frankly is the basis for many of the opinions you solicited - buy and learn.
Otherwise, slow down, read more and ask more fundamental questions to help you balance the tradeoffs - before making decisions that (unknowingly) severely limit your options and results.
That said - here's some technical stuff you didn't want to hear:
A little understanding will help you see the tradeoffs and do a little simple arithmetic to get what is most important to you .
- Your motor has an integrated controller that is rated at 35A @ 36V and can be adjusted up to 50A (about right when hooked to 48V - but you could leave it at 35A with 48V and give up some torque). It's your controller amperage as well as cruising current draw that must shape your battery buy.
You will need to choose a cell type such that the Ah rating times the 'C' rating matches the controller current draw for both Max (getaways, hills, etc) and continuous use (cruising - normal start/top and mean speed and load (snow!)). So a 15Ah pack with a nominal 2C rating will provide about 30A of current whereas the same pack made with 5C cells will provide 75A. If you continuously flog the battery at close to capacity it will have a detrimental effect on cycle life so many folks use a '1/2 C rating' rule of thumb as a tradeoff to minimize flogging and extend cycle life. Here is where that whole business about 'type of use' comes in (that you answered as 'every use from light to super heavy'). Running light loads will let you use a Ping - no problem since they are 2C batteries. But load the crap out of the bike for long periods in the snow and you need a higher 'C' rate (or Ah capacity) battery to carry the load without being damaged (eg one of the EM3EV batteries). So - pick your cell type based on use OR limit your use to match the cell type you can afford to buy or carry...
- Your range (without fudging for lots of start/stops, hills, etc) is:
Range = (Wh capacity of your battery) / (Wh/mi consumption) * (percentage Depth of Discharge)
Your DoD is probably 80% for LiFe and 90% for NMC and NCA (DoD = cycle life vs capacity trade-off - more opinion...)
You are a heavy pedaller so your consumption may be as low as 10-15 Whr/mi on the flat. In the snow it might be way more than 60. For comparison, it takes about 13whr/mi to move a mountain bike at 15mph without pedaling, about 21Whr/mi to do 20mph, and about 40Whr/mi to do 30mph. So what's your range? Well - from your specification (which is: many widely varying uses) - we just can't tell - it will depend...
My use changes based on what I learn, so although I have been pouring over this stuff for awhile now, I just get confused. Lots of acronyms that I don't understand, so I can read forever. You are right though and I take no offense whatsoever, and thanks for the info. I hold you all in very high regard and appreciate this and all the other responses. I won't defend my questions but I understand and appreciate what you said. I will take it from here and the admin can just close the thread as I will figure things out by just reading things already posted.
dnmun
1 PW
most of us look at other builds and you can usually see what someone has done because they take pictures and from our own experience looking at the pictures it makes sense as to why someone located a part here and the battery there, etc.
then just do it, build your 1st bike, then do the 2nd bike, then the 3rd. learning to avoid greenhorn mistakes like twist off on a brand new motor is the best reward for being patient and reading to see how you would do what the other person did, more than asking for someone to tell you what to do.
then just do it, build your 1st bike, then do the 2nd bike, then the 3rd. learning to avoid greenhorn mistakes like twist off on a brand new motor is the best reward for being patient and reading to see how you would do what the other person did, more than asking for someone to tell you what to do.
999zip999
100 TW
Secret cell insulator.
Calibike battery 48v15ah last longer at 22amp.
Calibike battery 48v15ah last longer at 22amp.
No one here want to dissuade you from posting, changing your mind, asking questions, or fault you for generally being overwhelmed by all this confusing stuff...Electro-Fox said:
I was trying to show (and apparently poorly) that your remarks about "confusion" and "throwing in the towel" are due in part to the way you are using this resource. You didn't actually ask about 'this chemistry vs that' looking for explanation - you started off rejecting the more common contemporary chemistries in the title - "Period" (added for emphasis, I guess). I am certain that many members never even bothered to read your thread or put other choices on the table for you - just because of that.
- This is like going to a car dealership without really understanding engine choices and proclaiming right off the bat "I want a car with a V8 - Period!". The salesman can only think you understand what you want and go from there. He has limited time and resources and it doesn't look like a case where talking about the advantages of other options is what you want - you have been very specific about your desires.
Now - if you had started by saying "Help me understand my engine choices" or "Is a V8 a good choice for what I want to do?" you can be certain the conversation would go differently.
Also - some folks post up and saying stuff like "I'm thinking of doing this - whaddaya think?" or "Help me choose a battery" and just embrace their noobishness (since everyone was at one time). The point being that every absolute decision you make up front, changes the course of the rest of the design. If you're not certain about some aspect or feature, put that uncertainty plainly on the table so folks can explain the consequences - etch it in stone only if you feel very strongly about it and understand it fully.
So - don't abandon ES and asking questions - just try to ask questions that people can answer in a way that moves your understanding and decisions forward...
dnmun
1 PW
the sense wires do not have to be identical in length. where in the world did that misinformation get started?
that is the biggest problem with this place. constant misinformation that nobody every points out is just that, misinformation.
everyone can post up anything they wanna say and never have an inkling of whether what they say is true or not.
so now most of the information here is just unsubstantiated opinions and has nothing to do with factual data.
that is the biggest problem with this place. constant misinformation that nobody every points out is just that, misinformation.
everyone can post up anything they wanna say and never have an inkling of whether what they say is true or not.
so now most of the information here is just unsubstantiated opinions and has nothing to do with factual data.
r3volved
100 kW
This is a really great reply!
Critical, yet non-aggressive ...and useful!!
Critical, yet non-aggressive
...and useful!!teklektik said:EF-
Not to be rude or harsh, but this thread is all over the place - you cannot possibly hope to get meaningful answers...
This is like walking into a bar and shouting - "What's the best pickup to buy?".
- The title itself unequivocally demands LiFe - and yet here you are on page 3 making a buy decision about NMC/NCA cells.
You are going to use a fork bag and won't consider a triangle bag - but now are going to use a triangle bag (goes to cell form factor).
You are concerned about 6% weight difference in NMC/NCA cells but started off with the heaviest/lowest energy density battery (LiFe).
You originally wanted to just jam as much battery as possible into a fixed bag size but now are asking about range.
You haven't given any distance for the commute and say nothing except that it's flat and you pedal a lot (which is easy on power consumption) - don't talk about traffic start/stops (which eat power), and then say you want to pull a trailer (which eats power on starts and hills), and want to ride in the snow (which is incredibly taxing) --- so basically a wide spectrum of use from super light to super heavy with no distance requirements.
And above all else - you didn't want to "go to school in order to buy a battery" and now are asking semi-technical questions, after having discouraged actual technical advice in favor of 'opinions'...
You can be certain that succinct and well-considered answers meeting your exact needs will ensue...
There is nothing wrong with asking noob questions, but you are starting out with critical constraining decisions, then reversing yourself. You may be frustrated by the variety of opinions expressed here - but you pretty much set the stage...
If you really don't want to understand this stuff, then just buy a big-ass battery from Ping or EM3EV (both well respected vendors with completely different offerings) and enjoy whatever it will do for you. Experience will fill in the blanks you don't wish to investigate up front. This generally works okay and frankly is the basis for many of the opinions you solicited - buy and learn.
Otherwise, slow down, read more and ask more fundamental questions to help you balance the tradeoffs - before making decisions that (unknowingly) severely limit your options and results.
That said - here's some technical stuff you didn't want to hear:
A little understanding will help you see the tradeoffs and do a little simple arithmetic to get what is most important to you .
- Your motor has an integrated controller that is rated at 35A @ 36V and can be adjusted up to 50A (about right when hooked to 48V - but you could leave it at 35A with 48V and give up some torque). It's your controller amperage as well as cruising current draw that must shape your battery buy.
You will need to choose a cell type such that the Ah rating times the 'C' rating matches the controller current draw for both Max (getaways, hills, etc) and continuous use (cruising - normal start/top and mean speed and load (snow!)). So a 15Ah pack with a nominal 2C rating will provide about 30A of current whereas the same pack made with 5C cells will provide 75A. If you continuously flog the battery at close to capacity it will have a detrimental effect on cycle life so many folks use a '1/2 C rating' rule of thumb as a tradeoff to minimize flogging and extend cycle life. Here is where that whole business about 'type of use' comes in (that you answered as 'every use from light to super heavy'). Running light loads will let you use a Ping - no problem since they are 2C batteries. But load the crap out of the bike for long periods in the snow and you need a higher 'C' rate (or Ah capacity) battery to carry the load without being damaged (eg one of the EM3EV batteries). So - pick your cell type based on use OR limit your use to match the cell type you can afford to buy or carry...
- Your range (without fudging for lots of start/stops, hills, etc) is:
Range = (Wh capacity of your battery) / (Wh/mi consumption) * (percentage Depth of Discharge)
Your DoD is probably 80% for LiFe and 90% for NMC and NCA (DoD = cycle life vs capacity trade-off - more opinion...)
You are a heavy pedaller so your consumption may be as low as 10-15 Whr/mi on the flat. In the snow it might be way more than 60. For comparison, it takes about 13whr/mi to move a mountain bike at 15mph without pedaling, about 21Whr/mi to do 20mph, and about 40Whr/mi to do 30mph. So what's your range? Well - from your specification (which is: many widely varying uses) - we just can't tell - it will depend...
okashira
10 kW
No the leads do not need to be the same length
There could be a scenario where a BMS senses voltage during balancing and if some leads have more resistance during higher current balancing it can lead to the cells not getting as perfectly balanced as possible... but this is probably pretty minor. The BMS should be smart enough to stop balance current for a second to properly sense voltage.
There could be a scenario where a BMS senses voltage during balancing and if some leads have more resistance during higher current balancing it can lead to the cells not getting as perfectly balanced as possible... but this is probably pretty minor. The BMS should be smart enough to stop balance current for a second to properly sense voltage.
John in CR
100 TW
"The best lifepo4 battery....period." I believe remains one built with A123 A grade cells.
arkmundi
10 MW
I'd be willing to make AMP20 packs using OSNPower provided cells and their kit and my cut aluminium plate, duct tape approach to construction at cost plus $12/hour labour, 100% cell cost up-front, balance-due on ready to ship. Expect low-interest, which would suit my cottage-industry approach to eBike services. Pack would come with wiring harness and Celllog 8S and/or balance charger leads to each cell. I'd warranty it for 1 year, with the right charger.John in CR said:
burningwings
100 mW
- Joined
- May 3, 2015
- Messages
- 37
I don't know what the best battery but have a good idea about the WORST battery . The 60v 24 ah 38140 cell from BMS Battery ! Utter trash 20% cell failure at 30 cycles. BMS will not respond to problem. NO CHINESE BATTERIES EVER AGAIN ! OUT $1000 !!
Electro-Fox
10 W
- Joined
- Sep 26, 2013
- Messages
- 69
teklektik said:
John in CR
100 TW
Electro-fox,
That's the kind of post you probably want to read again and just discard before submitting. I've done just that many times. Teklectik is a totally inoffensive and very knowledgeable and helpful forum member, and I think you read something into his post that wasn't intended at all. I certainly didn't read anything sarcastic or demeaning in his post. That's the an issue with forums, because the written word is created by someone with one mindset that is interpreted by the reader who can have a totally different mindset resulting in misinterpretations due to the lack of visual and aural cues we have with in-person discussion to set the tone and help determine meaning. That's all before giving consideration to the fact that forum members are from all parts of the world where customs are different as are discussions and writings.
ES works unbelievably well compared to other forums despite these challenges. I believe that's due in large part to us sharing such an incredible hobby. I make this post with only the best intent, so keep in mind that it's coming from someone known to be unintentionally rude and obnoxious on hopefully rare occasions.
John
That's the kind of post you probably want to read again and just discard before submitting. I've done just that many times. Teklectik is a totally inoffensive and very knowledgeable and helpful forum member, and I think you read something into his post that wasn't intended at all. I certainly didn't read anything sarcastic or demeaning in his post. That's the an issue with forums, because the written word is created by someone with one mindset that is interpreted by the reader who can have a totally different mindset resulting in misinterpretations due to the lack of visual and aural cues we have with in-person discussion to set the tone and help determine meaning. That's all before giving consideration to the fact that forum members are from all parts of the world where customs are different as are discussions and writings.
ES works unbelievably well compared to other forums despite these challenges. I believe that's due in large part to us sharing such an incredible hobby. I make this post with only the best intent, so keep in mind that it's coming from someone known to be unintentionally rude and obnoxious on hopefully rare occasions.
John
cycborg
1 kW
Electro-fox, in case you're still checking in here...
I see your system is up for sale. I'd urge you to take a breath, realize you're almost over the finish line, and decide how you're going to get there. The time and expense that you've already invested in this project indicates that a finished product is something that would be valuable to you, and not just sit in a garage after a few spins around the neighborhood. Of course one has to be careful about the sunk-cost fallacy, but I get the sense that you're giving up out of frustration, not due to a sober analysis that e-biking isn't for you.
You should go back and read teklektik's post. He points you to two approaches - jump in and buy a big battery from a reputable vendor, or analyze your riding style, terrain, desired speed and range, etc. and understand how these factors relate to the battery voltage, capacity, C-rate, and chemistry. Either of these is fine. But even if you go the analysis route, at some point you have to make a decision. What you end up with may turn out not to be optimal, but it will be something you can use, and getting some real-world experience will inform your next decision when you upgrade in a year or two or five.
And keep coming back here for help. This place is a fantastic resource.
I see your system is up for sale. I'd urge you to take a breath, realize you're almost over the finish line, and decide how you're going to get there. The time and expense that you've already invested in this project indicates that a finished product is something that would be valuable to you, and not just sit in a garage after a few spins around the neighborhood. Of course one has to be careful about the sunk-cost fallacy, but I get the sense that you're giving up out of frustration, not due to a sober analysis that e-biking isn't for you.
You should go back and read teklektik's post. He points you to two approaches - jump in and buy a big battery from a reputable vendor, or analyze your riding style, terrain, desired speed and range, etc. and understand how these factors relate to the battery voltage, capacity, C-rate, and chemistry. Either of these is fine. But even if you go the analysis route, at some point you have to make a decision. What you end up with may turn out not to be optimal, but it will be something you can use, and getting some real-world experience will inform your next decision when you upgrade in a year or two or five.
And keep coming back here for help. This place is a fantastic resource.
+1
You seemed to be spiraling out out control into Analysis Paralysis after initially deciding that you didn't want to go that route. This seemed to be very troubling and you had a fear of making a Big Mistake in battery selection - hence my post. But, the bottom line is that you have purchased a very expensive (and proprietary) motor/controller setup and are probably going to have a challenging time unloading it. When you compare that dollar hit to buying a quality battery from an outfit like EM3EV, there is financial downside to jumping out now does not look advantageous.
I would recommend that you pursue your thought to get the EM3EV triangle bag and get it with the INR18650-20R cells that Paul has on sale. These are 10C cells so the 17.5 Ah triangle battery will supply 175A if required. This is huge. Your motor, although rated at 500W (this is the continuous no-overheat rating) can suck up a 2000W using the 50A setting of the controller - giving you very zippy getaways. 50A is about 3C for the 17.5Ah battery but that's at the limit of some of EM3EV's cell types and leaves no headroom for battery aging. Since longevity has been one of your major concerns, the 10C cell type will give you lots of headroom and treat the battery very gently for a long life.
And remember - the projected life of a battery is the number of cycles to reach 80% capacity. You can keep using it, it just won't go as far per charge so you will still continue to get use if you oversize to begin with or have no fixed commute distance that becomes unattainable.
Read the Faco thread here - You will need to ensure you have the 'unlocked' kit to beat the speed limit, etc. There are no US speed limits, but there is a law about selling an ebike that can exceed 20mph. So - Falco has taken to locking down the controllers so LBSes can sell the things 'installed' without legal repercussions and then the new owners can legally 'unlock' the limit and ride on the road according to their State laws. This is a PITA, but something you will need to pursue.
Stop thinking and worrying - you've already anted up - finish the game and enjoy your efforts....
You seemed to be spiraling out out control into Analysis Paralysis after initially deciding that you didn't want to go that route. This seemed to be very troubling and you had a fear of making a Big Mistake in battery selection - hence my post. But, the bottom line is that you have purchased a very expensive (and proprietary) motor/controller setup and are probably going to have a challenging time unloading it. When you compare that dollar hit to buying a quality battery from an outfit like EM3EV, there is financial downside to jumping out now does not look advantageous.
I would recommend that you pursue your thought to get the EM3EV triangle bag and get it with the INR18650-20R cells that Paul has on sale. These are 10C cells so the 17.5 Ah triangle battery will supply 175A if required. This is huge. Your motor, although rated at 500W (this is the continuous no-overheat rating) can suck up a 2000W using the 50A setting of the controller - giving you very zippy getaways. 50A is about 3C for the 17.5Ah battery but that's at the limit of some of EM3EV's cell types and leaves no headroom for battery aging. Since longevity has been one of your major concerns, the 10C cell type will give you lots of headroom and treat the battery very gently for a long life.
And remember - the projected life of a battery is the number of cycles to reach 80% capacity. You can keep using it, it just won't go as far per charge so you will still continue to get use if you oversize to begin with or have no fixed commute distance that becomes unattainable.
Read the Faco thread here - You will need to ensure you have the 'unlocked' kit to beat the speed limit, etc. There are no US speed limits, but there is a law about selling an ebike that can exceed 20mph. So - Falco has taken to locking down the controllers so LBSes can sell the things 'installed' without legal repercussions and then the new owners can legally 'unlock' the limit and ride on the road according to their State laws. This is a PITA, but something you will need to pursue.
Stop thinking and worrying - you've already anted up - finish the game and enjoy your efforts....
dnmun
1 PW
i doubt if the BMS that paul uses is capable of more than 60A.
The controller has a max of 50A - there is no issue with the BMS rating.
The 10C rate is about how hard the battery will be pushed - the point being it will be running far below max spec regardless of the rider driving style.
This is about allaying EF's fears and ensuring he gets a robust build that he can enjoy.
Electro-Fox
10 W
- Joined
- Sep 26, 2013
- Messages
- 69
Well I will tell you guys, that I am a mature and smart man, and what I do for a reason. I seek advice and appreciate advice when it is given in a context that is supportive, even if that means that I get to hear some negative stuff. But let me tell you something else... I would NEVER EVER go to a thread that either one of you had started and post a comment that literally crushes an opportunity for you to sell something in the classifieds section. This thread is trending right now and a lot of people read it, and what do they find? Not one, but two posts commenting on how I am asking too much for something I am selling. Anything good about your post went right over my head with that stunt. Shame on you.
I am not a quitter, and I am not bailing or giving up on anything. But I have given up trying to sell that hub on this forum, and deleted the ad. And just so that you know, for anyone that is thinking of making their fat bike electric, that was actually a good deal. Those 72 hole rolling darryl rims (which is what you need for an electric hub) are not that easy to find. So it would actually be much easier for someone to get this setup, especially because I had a damn good wheel builder lace it up. It is even harder to find a person that can do that right. But your casual observations shot a hole in any opportunity for me to even get there with a potential buyer.
gawd almighty...
I am not a quitter, and I am not bailing or giving up on anything. But I have given up trying to sell that hub on this forum, and deleted the ad. And just so that you know, for anyone that is thinking of making their fat bike electric, that was actually a good deal. Those 72 hole rolling darryl rims (which is what you need for an electric hub) are not that easy to find. So it would actually be much easier for someone to get this setup, especially because I had a damn good wheel builder lace it up. It is even harder to find a person that can do that right. But your casual observations shot a hole in any opportunity for me to even get there with a potential buyer.
gawd almighty...
cycborg
1 kW
Offending content removed. Good luck with the sale.
Electro-Fox said:
Wow.
Go back and read my post - I said nothing of the kind.
There is no mention that you were asking too much - just a simple reference that you are trying to sell a motor/controller with a proprietary design and that you have significantly discounted it - money that could as easily have gone to your battery instead of just writing it off.
The fact is that the Falco motor has virtually no users on this forum - and the uniqueness and proprietary design is likely a primary factor: the motor and matching controller are 5 pole not 3 like just about every other ebike motor/controller. Unfortunately, it means you cannot upgrade to a new motor or controller without ditching the whole package. You are locked in to that manufacturer for everything. This is the reason you will have a hard time selling it - not your asking price.
Nobody posted in your For Sale thread and no comments were made in this thread about the wisdom of your Falco selection. It's a big forum and the content of all the threads is not going to be shaped by what you have for sale. You abandoned posting here after remarks about 'throwing in the towel'. Members here were trying to be supportive and assist. Don't get your knickers in a twist because you failed to post back and explain - we are doing the best we can with the information you provided -- but in the end a waste of all our time...
In your last posts here you have pointed out that you don't get along with ebike shops, ebike manufactureres, or folks on ebike forums - I will spare your characterizations of all these folks, but it might be good time to sit back ask why the rest of the world is so screwed up....
Good luck with your sale.
Gloop
10 W
Electro-Fox said:
I bought a dual-pack 30Ah battery from ping and had an end cell fail, had to open it up and solder a new cell into the packs.
I would buy 2 independant batteries as I think that is more redundancy on long bike rides or tours.
If i am wrong someone else feel free to pipe in.
