"off a little" - there is a HUGE descrepancy between 20% charge remaining around 42v VS 48.5v.
my numbers put 48.5v around 60% charge.
Using your "range" would give very little mileage out of a 48v battery. Something is off here.
Charging to 80% without a Satiator
- Thread starter Justin Fischer
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my numbers put 48.5v around 60% charge.
Using your "range" would give very little mileage out of a 48v battery. Something is off here.
Your forgetting you got your info from a bad chart. But what do I know. I'm just trying to right a wrong. Run your batteries down to 42 volts and let us know how long they last. That's 3.2 volts per cell. Lipos will puff if run below 3.6 in a short period of time and kill your cycle life. 3.75 is what i tell my customers not to go below.
Feliz
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Why would you want to use Lipo cells on your bike?
Feliz
What do you think 18650 cells are made of?
John
I don't sell 18650 cells. The lipos I sell would work great on an ebike. The problem is the size they come in. Mine are flat rectangles. Makes it hard to find a pack that they will fit in an ebike case. Though I'm sure it could be done. Not sure you would want to though. 18650 cells are round and have a metal case so there durable against bumps and they will conform to any size battery case.
What do you think 18650 cells are made of?
John
I don't sell 18650 cells. The lipos I sell would work great on an ebike. The problem is the size they come in. Mine are flat rectangles. Makes it hard to find a pack that they will fit in an ebike case. Though I'm sure it could be done. Not sure you would want to though. 18650 cells are round and have a metal case so there durable against bumps and they will conform to any size battery case.
bikerjohn
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Mark, I understand that the 18650 cells in the 52 volt Juiced Battery pack are a Lipo formula. What I am unclear about is how your chart supersedes the Juiced Website information? How are the voltage values on you chart calculated? Where can I find the equation used to generate your chart?
tomjasz
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My best advice is to work from the cell data sheet to get an accurate nominal voltage. That is the most accurate.`But that's kinda niggling the details and the 1S chart from MarkF is usable. Simple math from there. 10 times the charted numbers for a 36V pack, 13X for a 48V, and14X for a 52V pack. Confusing to some since the chart uses series and we're calculating parallel. But the percentage values I believe are correct. Exactly what I use in building and testing. (still learning and far from an expert, electronics is quite a leap from arboriculture and horticulture.) This is my preferred range. As often as I can but I charge to 100% unabashedly, when I need the mileage.
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I had to double-check - we are in the Juiced Bikes Forum, and the juicedbikes website states:
"Uses the latest in Lithium-Ion battery cell technology" for their battery packs.
So is the chart I created, that uses 42.1v as 20% and 51.5v as 80% correct? It sure seems so based on the low voltage cutoff Juiced recommends and the max charge voltage also given.
I'm sorry MarkF but your data/info seems to only be confusing and not applicable to these battery packs.
"Uses the latest in Lithium-Ion battery cell technology" for their battery packs.
So is the chart I created, that uses 42.1v as 20% and 51.5v as 80% correct? It sure seems so based on the low voltage cutoff Juiced recommends and the max charge voltage also given.
I'm sorry MarkF but your data/info seems to only be confusing and not applicable to these battery packs.
tomjasz
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A GA Panasonice has a
Nominal voltage 3.6V others list as Nominal Voltage (V): 3.6V-3.7V
Nominal voltage 3.6V others list as Nominal Voltage (V): 3.6V-3.7V
Chemistry isn't as important as good working numbers. These numbers work. They would change some with different nominal capacities. But two different chemistries CAN have the same nominal and full charge. We use 4.2 as the full charge and 3.7 as the nominal. Some batts are 3.6 or a bit over 2.7. We need not seat the details to take good care and get maximum use.
tomjasz
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ALMOST true. LOTS of hobby builders use hobby packs often called LiPo. The sarcasm belongs elsewhere. They're just batteries lets not overthink this.
tomjasz
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It makes far more sense and can be adapted to any size pack, to use individual cell voltages as a percentage.
Using 3.6V to 4.1V per cell is a great battery saving range. I try not discharge a 48v battery below 46.8. My controllers cut out at 42V or around 3.3V.
I guess I'm beating a drum here, but again, just a battery. I have two batteries I've been totally careless with and expect them to give me the 6th season.
Don't worry be happy, RIDE!
tomjasz
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Agreed on full charge for 18650 but I run my batts near 42v whenever I need the mileage. I have 5 into my sixth season in 2019 using 3.2v as the drop dead voltage. I prefer and often do 43v-45v on some packs, oversized for their mileage, and I see no difference in degradation. Last count I had 10 or 12 batteries. I use Grin's battery testing setup to review packs.
With your Graphene packs, I'll follow your advice to the T.
BTW each pack is a different chemistry.
OK I'll SU now!
KLee
Active Member
The 18650 batteries in the packs are lithium Ion, not lithium polymer, is there a difference? Are the voltage charts the same for both types of batteries? I am confused.
Feliz
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I said most, not all. There's a lot of misinformation being passed around and it would confuse anybody. I don't think any of you guys are battery experts.
SirJonathan
Active Member
I'm going to use the numbers provided directly from the manufacturer's website for their specific battery pack. I am interested in the science behind it, however, and find this discussion interesting.
Ravi Kempaiah
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@bikerjohn ,
This is entirely inaccurate. None of the mainstream ebikes use LiPo. Juiced 52V pack is NOT based on LiPo formula!!
They come under 18650 category with graphite as the anode, NMC (Nickel Manganese Cobalt) or NMO (Nickel Manganese Oxide) basec cathode and a liquid electrolyte.
The cells look like this in a pack:
Please refrain from spreading wrong information. None of the 18650 cells are classified under LiPo family. This is as inaccurate as it can get.
Li-Po cells use gel-like polymer electrolyte unlike organic liquid electrolyte (LiPF6 with EC/DMC/PC additives) found in 18650 cells. The cathode may have slightly different chemistry as well.
Li-Po suffer from short lifecycle compared to 18650 cells. Otherwise, we would find them on all bikes. Also, the gravimetric energy density is less (not the power density!).
The advantage of LiPo is they are lighter and can be moulded to complex shapes within the cellphones, making for easier fabrication process. But, these days, you can find Li-ion cells in cellphones as well.
A short summery of the differences:
Ravpower is a huge vendor of powerbanks . They have thousands of verified reviews on Amazon and they do offer neat products.
https://www.amazon.com/External-RAVPower-16750mAh-Time-Tested-Flashlight/dp/B00MQSMEEE/
Their blog provides some correct information. Here is the blog post and the related pic. http://blog.ravpower.com/2017/06/lithium-ion-vs-lithium-polymer-batteries/
Re: the original thread question.
Juiced or Ebikes.ca do offer correct information. If the values at 80% vary by 0.2 volts, there is absolutely nothing to worry about. It's alright.
As a PhD researcher working with scientists in this field, it makes me annoyed to see lots of misinformation floating around.
Here is a somewhat less techy video explaining the differences between different kinds of cells.
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Lithium Polymer (LiPo, LiPoly, etc.) is used for mobile phone and tablet batteries; think of their varying shapes and easy-to-puncture material. Contrast that with the steel-shelled 18650 cylindrical battery - which is standardized, hard, and cylindrical. 18650 (18mm by 65mm) batteries never share the characteristic of using a soft, malleable polymer pouch casing.
If we take a step back we can then see, that both the hard-shelled, and soft-shelled batteries use the same fundamental electrochemistry. They are both lithium-ion (li-ion, liion, etc.) batteries.
That is, they both give us usable energy by shunting lithium ions between the cathode and anode sheets. The ions move in one direction during charge, and in the other direction during discharge. This fundamental movement is present in both the hard 18650
What there saying here is a lipo refers to a soft pouch and a li-ion refers to a metal cylinder. But both batteries are made of the same lithium material.
I think the difference between the 2 charts is this. The chart me and Thomas posted is correct for standing voltage. The chart Juice posted is for low voltage cutoff LVC. That means lipos drop voltage while under a load. So if you want your pack at 46.8 after a ride, you might set the LVC to 42 volts.
If we take a step back we can then see, that both the hard-shelled, and soft-shelled batteries use the same fundamental electrochemistry. They are both lithium-ion (li-ion, liion, etc.) batteries.
That is, they both give us usable energy by shunting lithium ions between the cathode and anode sheets. The ions move in one direction during charge, and in the other direction during discharge. This fundamental movement is present in both the hard 18650
What there saying here is a lipo refers to a soft pouch and a li-ion refers to a metal cylinder. But both batteries are made of the same lithium material.
I think the difference between the 2 charts is this. The chart me and Thomas posted is correct for standing voltage. The chart Juice posted is for low voltage cutoff LVC. That means lipos drop voltage while under a load. So if you want your pack at 46.8 after a ride, you might set the LVC to 42 volts.
Wow Ravi
Let me start by saying a video posted to youtube made by some guy who bought some cells tells nothing and I wonder why you even posted that.
Your graph below that is incorrect too. The part where it says Chances of explosion, lipos are safe from explosion. Ask the many people who burnt there garages and cars down if lipos don't explode from overcharging. If fact, the reason 18650 explode more is because they are encased in a hard metal shell and not a soft pouch.
In all your post, I don't see anything about chemistry of the two.
Let me start by saying a video posted to youtube made by some guy who bought some cells tells nothing and I wonder why you even posted that.
Your graph below that is incorrect too. The part where it says Chances of explosion, lipos are safe from explosion. Ask the many people who burnt there garages and cars down if lipos don't explode from overcharging. If fact, the reason 18650 explode more is because they are encased in a hard metal shell and not a soft pouch.
In all your post, I don't see anything about chemistry of the two.
tomjasz
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This is getting totally overplayed. Perhaps Felix can square us away?
3.6-4.1v per cell and it’s as good as it gets, conserving battery life, with the current run of 18650 batteries. Go for a ride, start a savings can in the garage. Everytime you ride, stuff at least a Buck away. Chances are you’ll have enough to nearly replace, come the day.
And for anyone thinking LiPo isn’t popular, check out endless_sphere. That lot was riding on LiPo before this lot knew about eBikes. No I’m no expert. Hundreds of sales, a dozen builds, and I learn something daily. There a propensity on forums, with nom de plumes especially, to to from zero to expert in 60 minutes of googling.
And George, I’m beginning to see your point.
