Parallel wiring..perhaps a unique scenario?

[ebike11]

Also i meant that the Turnigy 6S pack was not on the RC forums battery chart. They seemed to have tested smaller sized packs. If hobbyking packs are a main sourse of batteries for RC hobbyists then it makes sense that someone has tested it..have to search more.

Again, for the hundreth time RC hobbyists aren't interested in the average number of discharge cycles they can expect from their RC Lipo pouch battery. Thus Turnigy and all other RC Lipo manufactures realized long ago (at the GETGO) that [inflated] high discharge C rates for a few seconds at "Full Throttle" is what turns the crank (interests) of your typical RC enthusiast ... NOT the average number of discharge cycles and cycle life longevity that can be expected from a RC Lipo battery.

On the backside label of my Turnigy 3s1p 2200mAh Lipo it says not to exceed 160 degrees F. Like has any RC hobbyist ever checked the temp of their Lipo to determine what C discharge for 60 seconds initiates swelling/puffing? That kind of data would be of interest to someone building a Turnigy 28s2p Lipp battery using those 20,000mAh cells supposedly rated at continuous discharge of 20amps. Would Turnigy ever publish such data for their 6 cell 20,000mAh Lipo ... not a chance even though they've done tests and have the data.

Turnigy never imagined that eight of their 6s 20,000mAh 22.2V, 444W (22.2V x 20C = 444W) and two 4s 20Ah would be used to build this ebike powerplant: 28s2p x 3.7V (nominal) = 103.6V ... 103.6V x 40A = 4144W. Theoretically a discharge rate of 20C (103.6V x 800A = 82,880W (28s2p). Even at a full throttle discharge rate of only 2C (28s2p) you'd theoretically need a motor capable of handling 8,288W. You can recheck my 2C discharge rate for your Turnigy 28s2p battery and let me know if my figuring is off and by how much.

Your mention of 240amps, 480amps and 800smps is for a brief time (seconds). At FULL throttle you would most likely end up in the hospital and possibly a fried motor depending on how long you were able to stay aboard your ebike. That's assuming you were using 6awg wiring and even then it would get HOT providing 480amps (28s2p).

Here's what i learned from your thread as to how Lipo manufacturers rate the MCD amperage that i never realized (knew) before that being ... The MCD energy density amperage of an RC Lipo is apparently identical it's Ah capacity rating. That isn't the case with Li-ion cyclindrical cells (e.g. 1865s & 2170s) ...

• Samsung 30Q 3000mAh high energy dense cell has a MCD rating of 15amps.

• LG M#6 3600mAh mild-mannered cell has a MCD rating of 6.1amps (Batemo spec).

• Molicell P42 4200mAh high energy dense cell has a MCD rating of 45amps (close to the same).

Just for the heck of it WHY not post on DogDipstick's thread ... https://endless-sphere.com/forums/viewtopic.php?f=14&t=117062 ... the following question: If you didn't use a Controller what theoretically is the maximum Watts you could pull from your EV Li-po pouch battery at FULL Throttle? It would be interesting to see if he would even answer and if so what kind of answer :wink:

Apparently your objective is: "Full Throttle for 10 to 15 minutes" and "480 amps (28s2p)" is IMO unrealistically, illusory, impractible ... an unachievable goal.

Mucho years ago as an RC flying hobbyist by the seat of my pants i got hooked and took the bait. Couldn't rest until i bought their latest Tenergy High Discharge (25C) and Fast Charge (3C) Lipo. Only read the 160F WARNING years later (never abused it). After years of collecting dust it's still in fair to good condition (typo error ... should read Tenergy not Turnigy).

For the hundredth time Im NOT worried about number of discharge cycles...I said it over and over but you keep bringing it up. The test sheets on RC forums are not mainly focused on cycles, rather if the C ratings are accurate on packs from hobbyking etc. However there isnt any test with the 6s, likely because of size and weight. Its the biggest form factor of a battery on their site

Also the qs273 is proven handle WAY over 8000w. Thats not an issue at all. Plus Im using 4awg and 6awg where possible. On phases and battery.

Regarding danger, thats part of the game. Ive gone at high speeds hundreds of times...the risk is noboby elses concern. Im not a child.

The goal is also of nobody elses concern besides my own. If I DID want to drain my packs in 10 to 15min. it would also be my choice.

You seem to missed the points that I mentioned at least twice of why Im using them.

1. No welding..easy connectivity in series from pack to pack. Copper crimping only for me
2. No issues with battery shipping. Hobbyking delivers to my door without many headaches.
3. Mounting benefits. I am able to mount them in different areas of the bike.

Yes I checked out his thread. His packs seem great but you still failed to concede the point that Dogdipstick made that Ah and current output both double when in parallel.

 

[eMark]

Also i meant that the Turnigy 6S pack was not on the RC forums battery chart. They seemed to have tested smaller sized packs. If hobbyking packs are a main sourse of batteries for RC hobbyists then it makes sense that someone has tested it..have to search more.

My best guess is that RC Lipo pouch amperage discharge ratings--whether 25C, 50C, or 130C are performed in a controlled lab at a brief pulse burst rating as short as 2-3 seconds. IMO, that's the only way Turnigy and other RC manufacturers can arrive at those high discharge rates. EV lipo pouch cell manufacturers would never use that kind of testing as it serves no useful purpose. The only purpose a RC Lipo 25C, 50C or 130C rating serves a useful purpose is for RC planes for a 2-3 second burst NOT for 10 to 15 minutes.

When i said "close to the same" the following comparision is a Li-ion 21700 with comparative figuring to a Turnigy nano-tech Li-po ...

• Molicell P42 4200mAh high energy dense cell has a MCD rating of 45amps (close to the same). No Peak Burst C rating
  as it's irrelevant with an ebike Controller having an amp rating of say 100amps.

• Turnigy nano-tech 5000mAh high energy dense cell with a MCD rating of 52amps and a 130C Peak Burst rating of
  5000mAh x 130C = 650,000mAh or 650amps which is guestionable marketing :wink:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

For the hundredth time Im NOT worried about number of discharge cycles...I said it over and over but you keep bringing it up.

This is NOT a RCGroup Battery forum. Rather it's an ES Battery forum for members that are interested in cycle life longevity. You'll just have to accept that fact (importance of cycle life) when posting in this ES Battery forum.

The test sheets on RC forums are not mainly focused on cycles, rather if the C ratings are accurate on packs from hobbyking etc. However there isnt any test with the 6s, likely because of size and weight. Its the biggest form factor of a battery on their site

Whether 12C or 20C it's usefulness is dubious if only for a brief 2-3 sec peak burst at 12C or 20C discharge amperage. It's possible that your RC Turnigy 20Ah 6s Lipo just happens to have an energy density cell discharge rating of 20amps for MCD. A 20A x 12C or 20C (240amps or 400amps) may be of some relevance for a Pylon or Aerobatic RC plane for a brief peak burst of speed for 2-3 seconds. However, a 24C, 50C or 130C brief peak burst of 2-3 seconds for a 170lb ebike (w/battery and rider) at an unrestricted (no Controller) FULL throttle would be considered irrelevant (IMO) in this ES Battery forum when an amperage Controller is essential for the well-being of a Li-ion 18650, 21700 cylindrical cell battery or an EV Li-po pouch cell battery.

Also the qs273 is proven handle WAY over 8000w. Thats not an issue at all. Plus Im using 4awg and 6awg where possible.

You really should be using EV Lipo pouch cells instead of RC Lipo pouch cells. One exception being if one only wants to test out their RC powered ebike on a 1/4 mile race track to set an ebike world speed record with unrestricted FULL throttle taking only a few seconds at a high discharge rate (e.g. 24C. 50C, 130C).

Regarding danger, thats part of the game. Ive gone at high speeds hundreds of times...the risk is noboby elses concern. Im not a child.

The goal is also of nobody elses concern besides my own. If I DID want to drain my packs in 10 to 15min. it would also be my choice.

Sounds like someday you may be attempting an RC Lipo powered ebike world speed record. So cycle life longevity is not important as long as it POWERS you and your ebike for say 1/4 mile in a few seconds or a lower discharge rate for at least 10-15 minutes ...

Yes I checked out his thread. His packs seem great but you still failed to concede the point that Dogdipstick made that Ah and current output both double when in parallel.

Where did i ever post that Ah and current output do not double when in parallel? Go back and copy/paste a quote where i ever implied that a cells' Ah rating and a cells' current energy density discharge rate do not double when paralleled?

 

[ebike11]

Also i meant that the Turnigy 6S pack was not on the RC forums battery chart. They seemed to have tested smaller sized packs. If hobbyking packs are a main sourse of batteries for RC hobbyists then it makes sense that someone has tested it..have to search more.

My best guess is that RC Lipo pouch amperage discharge ratings--whether 25C, 50C, or 130C are performed in a controlled lab at a brief pulse burst rating as short as 2-3 seconds. IMO, that's the only way Turnigy and other RC manufacturers can arrive at those high discharge rates. EV lipo pouch cell manufacturers would never use that kind of testing as it serves no useful purpose. The only purpose a RC Lipo 25C, 50C or 130C rating serves a useful purpose is for RC planes for a 2-3 second burst NOT for 10 to 15 minutes.

When i said "close to the same" the following comparision is a Li-ion 21700 with comparative figuring to a Turnigy nano-tech Li-po ...

• Molicell P42 4200mAh high energy dense cell has a MCD rating of 45amps (close to the same). No Peak Burst C rating
  as it's irrelevant with an ebike Controller having an amp rating of say 100amps.

• Turnigy nano-tech 5000mAh high energy dense cell with a MCD rating of 52amps and a 130C Peak Burst rating of
  5000mAh x 130C = 650,000mAh or 650amps which is guestionable marketing :wink:

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

For the hundredth time Im NOT worried about number of discharge cycles...I said it over and over but you keep bringing it up.

This is NOT a RCGroup Battery forum. Rather it's an ES Battery forum for members that are interested in cycle life longevity. You'll just have to accept that fact (importance of cycle life) when posting in this ES Battery forum.

The test sheets on RC forums are not mainly focused on cycles, rather if the C ratings are accurate on packs from hobbyking etc. However there isnt any test with the 6s, likely because of size and weight. Its the biggest form factor of a battery on their site

Whether 12C or 20C it's usefulness is dubious if only for a brief 2-3 sec peak burst at 12C or 20C discharge amperage. It's possible that your RC Turnigy 20Ah 6s Lipo just happens to have an energy density cell discharge rating of 20amps for MCD. A 20A x 12C or 20C (240amps or 400amps) may be of some relevance for a Pylon or Aerobatic RC plane for a brief peak burst of speed for 2-3 seconds. However, a 24C, 50C or 130C brief peak burst of 2-3 seconds for a 170lb ebike (w/battery and rider) at an unrestricted (no Controller) FULL throttle would be considered irrelevant (IMO) in this ES Battery forum when an amperage Controller is essential for the well-being of a Li-ion 18650, 21700 cylindrical cell battery or an EV Li-po pouch cell battery.

Also the qs273 is proven handle WAY over 8000w. Thats not an issue at all. Plus Im using 4awg and 6awg where possible.

You really should be using EV Lipo pouch cells instead of RC Lipo pouch cells. One exception being if one only wants to test out their RC powered ebike on a 1/4 mile race track to set an ebike world speed record with unrestricted FULL throttle taking only a few seconds at a high discharge rate (e.g. 24C. 50C, 130C).

Regarding danger, thats part of the game. Ive gone at high speeds hundreds of times...the risk is noboby elses concern. Im not a child.

The goal is also of nobody elses concern besides my own. If I DID want to drain my packs in 10 to 15min. it would also be my choice.

Sounds like someday you may be attempting an RC Lipo powered ebike world speed record. So cycle life longevity is not important as long as it POWERS you and your ebike for say 1/4 mile in a few seconds or a lower discharge rate for at least 10-15 minutes ...

Yes I checked out his thread. His packs seem great but you still failed to concede the point that Dogdipstick made that Ah and current output both double when in parallel.

Where did i ever post that Ah and current output do not double when in parallel? Go back and copy/paste a quote where i ever implied that a cells' Ah rating and a cells' current energy density discharge rate do not double when paralleled?

You STILL gloss over the reasons why Im using these brick packs...here is the list again for the 4th time I think..i lost count

1. No welding..easy connectivity in series from pack to pack. Copper crimping only for me
2. No issues with battery shipping. Hobbyking delivers to my door without many headaches
3. Mounting benefits. I am able to mount them in different areas of the bike.

Also there are are plenty of ebikes using lipo bricks to power their motors. I linked some on youtube and there are members on here using Graphene etc.

This forum does not explicitly say I cant talk about HK lipos. They are a battery and they are what im using.

I may get EV lipos in the near future for my next pack but not at the moment

For someone who said they are leaving the thread, they sure do post lengthy replies :lol: :lol:

 

[eMark]

You STILL gloss over the reasons why Im using these brick packs

Where has Turnigy ever referred to any of its RC lipos including the 20Ah 6S as a "brick" battery as is the 'case' with other Lipo batteries that are presumably reinforced to minimize swelling?

here is the list again for the 4th time I think..i lost count

1. No welding..easy connectivity in series from pack to pack. Copper crimping only for me
2. No issues with battery shipping. Hobbyking delivers to my door without many headaches
3. Mounting benefits. I am able to mount them in different areas of the bike.

Those same advantages can apply to both 18650 and 21700 Li-ion cells (e.g. NESE - No Solder/No Spot-Welding).

Also there are are plenty of ebikes using lipo bricks to power their motors. I linked some on youtube and there are members on here using Graphene etc.

Yes, but not your typical RC Lipos with inflated continuous discharge rates; 12C, 24C, 50C and 130C.

This forum does not explicitly say I cant talk about HK lipos. They are a battery and they are what im using.

No one ever said you couldn't. Some of your RC lipo MCD and amperage beliefs are unrealistic for the sake of ebike practicallity.

For someone who said they are leaving the thread, they sure do post lengthy replies :lol: :lol:

Doubt you can find that [supposed] quote or the other to copy and paste in your next reply
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Here are some of your quotes that could use some further explanation to help you reach your objective ...

At the moment my pack is 28s lipo 20Ah pack. Its connected to a 300A ANT BMS. I can monitor each cell because the BMS can handle 32s

Are you planning/hoping on being able to continuously discharge 240amps at 6C for at least 10 to 15 minutes (40Ah x 6C = 240A)?

If i run 20Ah x 12C rating then (240amps continuous)
But doubling the capacity would allow me to increase the controller to 480 battery amps

Your ANT BMS is only 300A. So, how long do you actually hope to supply 240amps continuous to "the qs273 is proven handle WAY over 8000w". Do you realize that (28s1p nominal voltage (103.6V) x 240amps (12C) continuous discharge = 28,224W, BUT for how long ? To achieve 8000watts figuring nominal voltage you only need a continuous discharge of 68amps (3.4C) for 8000watts (theoretically), but for how long?

I was assumption that Ah x C rating gives max. Current output. I thought ive read that many times.

That's only true if Ah rating is same as the cells' continuous discharge energy density rating. That Turnigy nano tech 8s 5000mAh 130C rating suggest that its continuous discharge energy density rating is 50A.

These packs have a 12c continuous and 20c 10 sec. burst

That's only true if the cells' continuous energy density discharge rating is 20 amps. A 20Ah rating is NOT the same as a cells' continuous discharge energy density rating. What data proof test exists to support 12c continuous and 20c 10 sec ??

Correct me if wrong, but your 28s2p (103.6V nominal charge x 40amps = 4,144watts or at most 4,704watts at FULL charge.

 

[ebike11]

You STILL gloss over the reasons why Im using these brick packs

Where has Turnigy ever referred to any of its RC lipos including the 20Ah 6S as a "brick" battery as is the 'case' with other Lipo batteries that are presumably reinforced to minimize swelling?

here is the list again for the 4th time I think..i lost count

1. No welding..easy connectivity in series from pack to pack. Copper crimping only for me
2. No issues with battery shipping. Hobbyking delivers to my door without many headaches
3. Mounting benefits. I am able to mount them in different areas of the bike.

Those same advantages can apply to both 18650 and 21700 Li-ion cells (e.g. NESE - No Solder/No Spot-Welding).

Also there are are plenty of ebikes using lipo bricks to power their motors. I linked some on youtube and there are members on here using Graphene etc.

Yes, but not your typical RC Lipos with inflated continuous discharge rates; 12C, 24C, 50C and 130C.

This forum does not explicitly say I cant talk about HK lipos. They are a battery and they are what im using.

No one ever said you couldn't. Some of your RC lipo MCD and amperage beliefs are unrealistic for the sake of ebike practicallity.

For someone who said they are leaving the thread, they sure do post lengthy replies :lol: :lol:

Doubt you can find that [supposed] quote or the other to copy and paste in your next reply
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Here are some of your quotes that could use some further explanation to help you reach your objective ...

At the moment my pack is 28s lipo 20Ah pack. Its connected to a 300A ANT BMS. I can monitor each cell because the BMS can handle 32s

Are you planning/hoping on being able to continuously discharge 240amps at 6C for at least 10 to 15 minutes (40Ah x 6C = 240A)?

If i run 20Ah x 12C rating then (240amps continuous)
But doubling the capacity would allow me to increase the controller to 480 battery amps

Your ANT BMS is only 300A. So, how long do you actually hope to supply 240amps continuous to "the qs273 is proven handle WAY over 8000w". Do you realize that (28s1p nominal voltage (103.6V) x 240amps (12C) continuous discharge = 28,224W, BUT for how long ? To achieve 8000watts figuring nominal voltage you only need a continuous discharge of 68amps (3.4C) for 8000watts (theoretically), but for how long?

I was assumption that Ah x C rating gives max. Current output. I thought ive read that many times.

That's only true if Ah rating is same as the cells' continuous discharge energy density rating. That Turnigy nano tech 8s 5000mAh 130C rating suggest that its continuous discharge energy density rating is 50A.

These packs have a 12c continuous and 20c 10 sec. burst

That's only true if the cells' continuous energy density discharge rating is 20 amps. A 20Ah rating is NOT the same as a cells' continuous discharge energy density rating. What data proof test exists to support 12c continuous and 20c 10 sec ??

Correct me if wrong, but your 28s2p (103.6V nominal charge x 40amps = 4,144watts or at most 4,704watts at FULL charge.

Ok well if you want to get picky about the wording then Ill change the sentence for you even though know you exactly know what i meant

"You STILL gloss over the reasons why Im using this "product"

Advantages, disadvanges or anything in between makes no difference to ME. Im using what I want to use and I dont care about other recommendations or alternative cell ATM

So for the 5th time...

1. No welding..easy connectivity in series from pack to pack. Copper crimping only for me
2. No issues with battery shipping. Hobbyking delivers to my door without many headaches.
3. Mounting benefits. I am able to mount them in different areas of the bike.

Thare are plenty of ebikers using "products" from HK that even have higher C rating than mine like the Graphenes

My practicality and realism is on me and nobody else. Maybe my goal is impracticality...my choice if it is
You said this forum is for members interested in cycle life longevity...are you sure? Did you ask EVERY member if their interest is cycle life???

My Ant BMS has the discharged side bypassed...no issues there FOR ME. Please dont reply about the dangers, the risks, the impracticallity etc. Ill skim past that part.

I originally asked a simple question in my first post about wiring in parallel. If the answer was yes or no then it would have been sufficient instead of essay posts. But its up to you if you want to spend your time typing so much. Its YOUR time so i couldnt care less. Have at it ))

 

[ebike11]

[/quote]
Amberwolf is more qualified to answer such questions. Wishing you good success in accomplishing your objectives ... so will bow out of this thread :thumb:
[/quote]

Here is your quote...i wouldnt have said it if i didnt read it from you...unless you were hacked

verb
bowed ​out; bow​ing ​out; bows ​out
Definition
intransitive ​verb
: RETIRE, WITHDRAW

 

[john61ct]

Yes OP your call, departures from "the norm" are just fine.

Running at true 10C continuous does mean 4-5min "flight time", if that's OK with you NP

25C peak is very rarely sustainable for more than a few seconds, and really these days HK / Turnigy / Panther graphene will reach EoL much quicker than the lines at the current top of MCSGUY's charts.

So when they reach EoL, maybe only 100-200 cycles, replace with better

Liperior us not more expensive, but much better value

SMC is pricey but at higher C-rates, even 30-40C bursts, will keep pushing amps longer, with lower V drops.

And another maybe dozen product lines are now better than anything HK delivers these days, they used to be top notch but sadly not anymore.

All this just offered to you, obviously do with it what you like.

 

[john61ct]

Above C-rates are real, based on observed and repeatable evidence.

Absolutely unrelated to vendor nameplate ratings, pure fiction.

 

[ebike11]

Yes OP your call, departures from "the norm" are just fine.

Running at true 10C continuous does mean 4-5min "flight time", if that's OK with you NP

25C peak is very rarely sustainable for more than a few seconds, and really these days HK / Turnigy / Panther graphene will reach EoL much quicker than the lines at the current top of MCSGUY's charts.

So when they reach EoL, maybe only 100-200 cycles, replace with better

Liperior us not more expensive, but much better value

SMC is pricey but at higher C-rates, even 30-40C bursts, will keep pushing amps longer, with lower V drops.

And another maybe dozen product lines are now better than anything HK delivers these days, they used to be top notch but sadly not anymore.

All this just offered to you, obviously do with it what you like.

Thx for the i fo..ill consider those for another pack. However does SMC and Liperior ship internationally? Im not in the US

 

[john61ct]

Start participating in the discussions over there, founders of both companies are active, and 99% of the other regular participants know more than I do.

The location of the company is usually unrelated to both where the cells are made, nor the markets they serve.

There are also shopping / shipping forwarding services.