Turnigy Multistar 10C 10AH versus Allcell pack comparison

I started yammering on about this on the endless sphere facebook page when the topic of the new turnigy multistar packs came up and I thought i'd go into detail here.. so here goes...

References:
http://hobbyking.com/hobbyking/stor...0mAh_Multi_Rotor_Lipo_Pack_US_Warehouse_.html
http://www.chicagoelectricbicycles.com/Batteries.html
http://www.ebikes.ca/shop/ebike-parts/batteries/b4820lim-kit.html

If my math is correct on calculating watt hours per KG, then..

The former gold standard: turnigy 20C 6S ( these tend to deliver a little more capacity than 5ah, but i'm going to say 5ah anyway. )

3.8v x 6S x 5AH = 114whrs
pack is 765g
114whrs / 0.765kg = 149whrs/kg

Turnigy Multistar packs: ( Christofer Parham/icecube57 has tested these to deliver a little more than stated capacity as well )
3.8v x 6S x 10AH = 228whrs
pack is 1189g
228whrs / 1.189kg = 191.75 whrs/kg

So the turnigy multistar 10C vs. the turnigy 20C means for a 22% increase in capacity per weight, which is pretty impressive.

Allcell 48v 13ah pack ( Nominal voltage is approximately 3.7 volts )
3.7v x 13S x 13AH = 625whrs
625 / 3.764g = 166whrs/kg

Alternate comparison

ebikes.ca has 48v 20AH allcell batteries for sale, so this can be a more straight comparison.

Allcell 48v 20AH = 962whrs ( 3.7v nominal ), 5.830kg / 12.85lbs. or 165whrs/kg
Turnigy multistar 12S 20AH = 912whrs (3.8v nominal ), 4.756kg / 10.5lbs or 191whrs/kg

Now, i am not certain if the charger weight is included into the allcell weight figures. This may skew the discussion.

As for economics..

A turnigy multistar 12S 30AH = 15.7lbs, $588.66 ( add 1lb for extra interconnections to be fair and you're at 16.7lbs ) and is rated to deliver 300 amps.

Allcell 48v 26AH pack is going to weigh 16.4lbs and will cost you $1499 and is probably limited to 25A or 40A output by the BMS.

Extra cost of RC charger and interconnections aside, i think we know the winner..

Notes on nominal voltage and performance

The allcell 48v pack is going to have a higher nominal voltage than a 12S Lipo at very low load levels, which frankly, are far below what we would ever use an allcell pack at. The RC lipo will come in at 45.6v nominal, the allcell should come in at 48.1v.
But consider this, under a typical ebike load, you are going to see the allcell battery give you significant voltage sag. This is going to mean that significantly less watt-hours are delivered as advertised. This brings the actual deliverable watt-hours of the allcell battery down even further for most eBikes.

More info about this devil in the details.



This is a discharge graph for the LG 18650 B3. You will notice a large spread in the nominal voltage in the discharge.

1/10C: approx 3.75v nominal.
1/5C: approx 3.7v nominal.
3/4C: approx. 3.575v nominal.

Ouch.
It would be fair to guess that at 1C usage, the allcell pack should give you around 3.5v nominal. This brings the nominal voltage for a 48v pack down to 45.5v, which is just about what voltage the 10C RC Lipo would be delivering at a 1C discharge.

So under a 1C continuous load for both batteries, we could assume that the all cell pack is delivering 910 watt hours, and the hobbyking lipo pack is probably 900-910 actual watt hours delivered as well, and that is being generous to the allcell pack because the LG 18650 B3 is probably losing some amp hours for certain under 1C continous load, where the hobbyking pack is very likely delivering the full amp hours rated.

If we look at what the LG 18650 B3 is doing at about 2C, it's not a pretty picture at all. You've got the cells at 3.4v nominal, and they are making tons of heat ( which is why these allcell packs come with the cells surrounded by a fancy wax - to soak up the heat and allow them to operate at this high rate.... but barely! )

Another note about weight

Comparing the weight of a battery pack with a BMS, interconnections, wax, and maybe even a charger figured into the weight figure is not fair. If you end up building a turnigy multistar pack with a few packs in parallel ( 20, 30, 40ah.. ), you may very well end up adding around a pound or so to the pack. What i can say for certain is that a turnigy multistar will equal or greater watt-hours per pound in the end.

In summary..

The new turnigy multistar packs have the best 'bang for the buck' ( in terms of weight, cost, and power output ) than the leading ebike battery pack. The cost is almost a third of that of an equivalent allcell pack would cost. Under a 1C load, a 12S hobbyking pack can quite possibly deliver the same nominal voltage as an allcell pack, despite having 1 less cell in series. For medium-high power builds looking to keep weight down, these are very ideal batteries. For low power builds, these are still excellent.

The downside is the usual safety concerns with RC Lipo, and a lower cycle life. You will also need to make interconnections and buy a balancing RC Charger on top of the prices quoted. Hobbyking continues to occasionally ship packs that are duds, and approximately 10% of what they ship out has a cell which is an underperformer or simply not matched to the pack and that will cause headaches. An allcell pack comes with support and warranty. If you are not a DIYer and you can afford an allcell pack, and want American support, it still may be your best choice at the moment if you are looking for low weight.

Your math is wrong. The RC lipos are rated 22.2V 6 cell makes 3.7V per cell. so the Multistar have 186,7whrs/kg.
And we don't know how Christofer Parham/icecube57 tested these ? what conditions and parameters. I can test a 25R 18650 from 4.2V down to 2.5V with 0.2A and i get >2550mAh.
Also we have no data for the cycle life from these new RC lipo.

The economics calculation don't includes cycle life, shipping cost and bits&peaces to connect the lipos into a real battery.

A Sammi 25R or Sunny VTC5 or LG HE2 build would crush them both in all category. The VTC5 even in max. Amp output.
They have 200whrs/kg VTC5 even a bit more 205whrs/kg
They have longer calendar and cycle life than RC lipos.
They are way more robust and don't burn your bike down if failure happens. (maybe also good for economics?)
They have quality control.

You are comparing a new semi DIY battery with a ready to use and tested factory battery with older technology cells that's not fair.

My conclusion is:
semi DIY RC lipo nay.
DIY 18650 yep.

The actual nominal discharge is more like 3.8v. Hobbyking quotes 3.7v because that is what you get under a very hard load ( typical for RC car/airplane use ), but the discharge curve tells you a different story.



^-- typical RC Lipo discharge curve. Notice that at 3.7v, you've drained about 70-80% of the capacity... would you call 70-80% the nominal point? i wouldn't.

The way i rate RC Lipo capacity is from the top ( 4.2v ) to where the cliff begins ( ~3.5v ). Around here, you typically get the full capacity stated. Below 3.5v is sketchy if you do not have a BMS, so i don't even tap into that extra capacity.

icecube57 tested his packs and got up to 10.5AH out of some of them. I did not include that into my calculations, so i was being sort of generous.
Some discussion is here: http://endless-sphere.com/forums/viewtopic.php?f=14&t=61672

We have a lot of cycle life data if you sift through the forum. Some people have gotten as much as 600 cycles out of RC Lipo, but typical is more like 300. I have never had to commute to work, so i have a 4 year old pack of turnigy 20C at ~200 cycles still going strong at 4 years now.

DIY 18650 can be excellent. But i'm comparing to what is commercially available and does not require buying a tab welder and all that business. RC Lipo and commercial packs are the most common because they are the easiest to build.

If you understand how to do a statistical analysis over a discharge curve, i'd love to have a proper 'nominal' calculation.

Attached is an image describing why i think that 3.8v nominal is a correct figure for RC Lipo. This pack was only charged up to 4.15v per cell.

3.0v is the stated cutoff point for RC Lipo, keep in mind.

http://lib.store.yahoo.net/lib/theshorelinemarket/LG-18650-2600.pdf
http://www.cnabattery.com/documents/18650b3.pdf

Note: here are two product spec sheets for the LG 18650B3. It states a 3.65v nominal voltage. If you do a proper statistical analysis on the hobbyking battery, you will find that it is at least 0.1V nominal higher.

*especially during high loads*

You can shift my watt hours per KG calculation for both batteries. But this does not change my conclusion. Especially under high load..

In regards to cycle life, LG states 300 cycles to 80% in both of these spec sheets.
Both of them say that 0.2C is the standard discharge rate.

It's possible that these are outdated spec sheets, but that would mean that they're probably on par with lipo.

My assumption is that the rated voltage is so chosen that the Wh can be calculated.
So i think the IR rises with the state of discharge and that's what shifts the rating to the lower than expected.

Yep full 300 cycles worst case. If you use them carefully than there should be 900-1100 cycles be possible.

\/ampa said:

. I can test a 25R 18650 from 4.2V down to 2.5V with 0.2A and i get >2550mAh.

A Sammi 25R or Sunny VTC5 or LG HE2 build would crush them both in all category. The VTC5 even in max. Amp output.
.

Click to expand...

The official Samsung 25R data sheet shows the average voltage at 10Amp discharge (4C) to be 3.4 volts.
At 20 A it's down to 3.2 volts... And the temperature hits 106 C in 5 mins !!
And.....various users have stated the Samsung to be a better "power" cell than the Sony .
http://endless-sphere.com/forums/download/file.php?id=130053

Some 18650 cells look really good on paper until you see a discharge graph and think about your use case. A cell that is rated for 10C is another matter. It's easy to give it a 2-4C load and get closer to the full watt hours claimed out of it with an ebike. A 10AH multistar pack delivering 2C (20 amps) is gonna perform pretty damn well.

That's why these kick butt.



Here's an extreme example of an 18650 cell. 3.4ah 18650... sounds badass, right?
Reality: you're going to get about 3.1ah out of those cells pushing them at a bit below 1C and they are now ~3.45v nominal.
They're also gonna be scalding hot from blowing 10% of their power to heat, and won't last long.

If you wanted to do a really monster size pack though and discharge it at practically a trickle, i'd go with a cell like that for sure. I'd be running it at 0.25C at most.. you'd just need a lot of space for 100 amp hours... hehe

\/ampa said:

My assumption is that the rated voltage is so chosen that the Wh can be calculated.
So i think the IR rises with the state of discharge and that's what shifts the rating to the lower than expected.

Yep full 300 cycles worst case. If you use them carefully than there should be 900-1100 cycles be possible.

Click to expand...

Again... The Samsung factory data shows that with a 4C cycle the capacity has dropped 30% to 1.8 Ahr, (5.5Whrs), after 250 cycles.!
These are "power" cells, so you are not going to pussy about at 0.2 C discharge just to extend cycle life.

Hillhater said:

\/ampa said:

My assumption is that the rated voltage is so chosen that the Wh can be calculated.
So i think the IR rises with the state of discharge and that's what shifts the rating to the lower than expected.

Yep full 300 cycles worst case. If you use them carefully than there should be 900-1100 cycles be possible.

Click to expand...

Again... The Samsung factory data shows that with a 4C cycle the capacity has dropped 30% to 1.8 Ahr, (5.5Whrs), after 250 cycles.!
These are "power" cells, so you are not going to pussy about at 0.2 C discharge just to extend cycle life.

Click to expand...

For full 4.2V to 2.5V. There is no way someone will use them like that in a EV.
Tesla gives 8 years warranty on there 18650 li-ion system.

If you have a hour spare time watch.
[youtube]pxP0Cu00sZs[/youtube]

\/ampa said:

For full 4.2V to 2.5V. There is no way someone will use them like that in a EV.
Tesla gives 8 years warranty on there 18650 li-ion system.

Click to expand...

No way you would use HK LiPo in an EV either !....but we are talking about practical Ebike sized packs..10Ahr, 36 V and such like where you do want to get most of the capacity used.......or you would choose a smaller lighter pack.
And with those cells you have to dip down to under 3 volts to use that capacity.
Oh, and those Tesla packs only ever see 3C max , and have a very complex cooling system to help cell life.

And on that other point of yours about assembly....

\/ampa said:

economics calculation don't includes cycle life, shipping cost and bits&peaces to connect the lipos into a real battery.

Click to expand...

...do you actually realise how simple it is to connect 2 or 4 packs of these LiPo together....compared to the similar efforts and resources needed for connecting the equivalent 48 or 96 individual cells ??

You don't have to dip down to 3v and you never should on a lipo pack, because the chances of you having a perfectly balanced pack that has all the cells rising and falling in sync is like 0.01% 3.5v average is where lipo starts to get real sketchy with voltages.

The turnigy packs often have more capacity than stated. The capacity that they advertise is more like a nominal capacity. Some people have seen all the way up to about 5.15ah on the 5ah packs.

I wish i could find the picture but i remember disassembling old turnigy packs and they had little stickers on the cells that said 5120, 5160, 5100, etc. Presumably markers of capacity for that cell.

It's the zippy packs that underperform both in C rate and capacity, and it's always been that way - always falling about ~5% short in capacity, and discharge rate is usually overstated by a factor of two. It was real disappointing when they came out with the 15C 5AH 6S zippy because i was getting about 4.7-4.8AH out of the things when they were brand new. The 8AH zippies were something like 7-7.5AH in reality as well.

I will get icecube57 to chime in here because he is one of the first testers of the multistar packs and posted a lot of graphs on the endless sphere facebook page.

Hillhater said:

\/ampa said:

For full 4.2V to 2.5V. There is no way someone will use them like that in a EV.
Tesla gives 8 years warranty on there 18650 li-ion system.

Click to expand...

No way you would use HK LiPo in an EV either !....but we are talking about practical Ebike sized packs..10Ahr, 36 V and such like where you do want to get most of the capacity used.......or you would choose a smaller lighter pack.
And with those cells you have to dip down to under 3 volts to use that capacity.
Oh, and those Tesla packs only ever see 3C max , and have a very complex cooling system to help cell life.

And on that other point of yours about assembly....

\/ampa said:

economics calculation don't includes cycle life, shipping cost and bits&peaces to connect the lipos into a real battery.

Click to expand...

...do you actually realise how simple it is to connect 2 or 4 packs of these LiPo together....compared to the similar efforts and resources needed for connecting the equivalent 48 or 96 individual cells ??

Click to expand...

Make advantage of the higher whrs/kg. Just get extra capacity and don't charge more than 4V. Small battery's don't life long when used always full. That is why i hate all these OEM ebikes with undersized battery's and too high charge voltage. Its just stupid.

Always when i see a RC lipo build i see a dangerous fragile bundle of chaotic connected sometimes puffy serial to parallel cell packs.
2or4 no here in the case of topic its 6pcs of 6s. How to balance them when connected?
I better sit some days to build a spot welder and a quality li-ion pack than mess with RC-lipo. Horses for courses.

You are comparing different purpose battery.

Allcell are used for low power reliable high cycles safe high cost scenarios.

Hobbyking is for relatively low cost, unsafe, compact, DIY, unreliable, low charge cycles scenarios.

What I would use HK lipo on? An experimental quick setup, potentially high power, low reliability, juryrig ebike with intention to change out the battery and other components quickly for either upgrades or broken parts.

Where would I use allcell? I would use it on reliable low power clean built commuter oriented safe ebike. It would be much closer to production ebike intended for long term uses.

So IMO, this is not a fair comparison without knowing what the use is for.

It would be fair if you are comparing HK multistar with the turnigy lipo or nanotech then it makes sense. Or if you compare allcell with the Nissan leaf battery or A123 cells then it would make sense.

Man I'm reading this and it's like people refuse to believe how awesome these packs are. I tested the multistar battery and found that they are very generous on caps capacity. I had one as high as 10.7ah. This was with the pack being taken from 4.2 down to 3v a cell. Compared to other large format lipo like the zippy 8ah they deliver all of their capacity with most if not all of it being delivered above 3.5v a cell. The ur actually gets better during the discharge vs getting worse. The pack actually delivers the same exact capacity whether it was discharging at 5a or 25a. I could test higher but I'm convinced that it can run most 50-60a builds in a 2p configuration. My last pack consisted of 9 zippy 8sh batteries for about 1.6kwh tested confirmed usable capacity. The pack weighted about 26-27lbs. My current pack consists of 8 10ah multistar batteries with a combined capacity of over 1.8kwh and the pack weighs 21lbs. This build is a bbs02 system for 48v 40ah in a Falcon EV Frame bag. Max load will be 25-30a ensuring the pack will never be stressed due to it being easy to have an oversized pack and my discharge rate never exceeding 0.6-0.7c. Even with age leading to capacity loss you are still well ahead of the game. The 8sh zippy I had so about 5-10%capacity loss after 1 year or 150-200 cycles and they were abused on a high amp setup. The packs never really gave full capacity even when new. Roughly 95% capacity and to get that they were struggling at 3v a cell. These multistar have a higher voltage and higher capacity and deliver it all within the adjusted conservative safe range of lipo.

That main point always comes up when RC lipos comes up and i sorta understand your position. With my first month of lipo usage i was in a position where i had to make a panicked phone call to a member here cuz i was a dumb newb and was scared of what happened if i made an error. I learned very quickly how to handle the stuff and then it became my mission to educate others on how to use it safely. Un-bmsed lithium cobalt packs are like a semi automatic rifle or high end sports car. With awesome power comes awesome responsibility and understanding of safety.

My main turnigy pack has only been in service for 4 years... i wouldn't call it unreliable. It's only unreliable if you don't test your packs for defects ( via cycle testing on a graphing charger ) as soon as you get them and then proceed to do something dumb like bulk charge it and never check the individual cell voltages.

Honestly i would graph the discharge of an 18650 pack as soon as it arrived as well, simply in order to know the truth about that pack before i was out of the warranty period.

We're generally DIYers so i'm speaking to you guys. Not the person who bought some 350w electric bike at a store for $3,000 and thinks it's so cool.. and wow, that allcell battery is 'so light'

Ever since I got out of my greenhorn stage I laugh and shake my head at lycra and I'll informed ebike adopters and bike shops. I show that my 2k dollar bike can go 120miles on a charge vs their 2-6k bike or ebike with underwhelming electric power and battery or ultra light carbon fiber frame and wheels. I'm happy you can go 40-60miles on your 18lb bike where does that leave you. After 5-10 bucks in energy drinks bars and supplements it's the bike that keeps on taking. I'd rather spend my 8 cents and get my exercise and feel refresh instead of exhausted and also not feel that range or power anxiety from crappy batteries and motor/controller combinations.

Changing the car's oil at home will always be cheaper compared getting it changed at the dealer. But it is not for everyone.

Just be open minded and know maintaining lipo is not for everyone. I am sure if someone who wanted these pack would've gotten them and there is no need dissing another type of battery just because of their high price. Different products for different markets.

It's all about capacity for me too. When i saw that you could stuff 40AH 12S of this new pack into a falcon EV / em3ev triangle bag, i was hooked and had to do the math to get an idea of exactly how much better those were than the typical 5AH Turnigy.

Look what sells in the EV market... it's the Model S with it's huge battery pack. You don't have to worry about range anxiety in a car with that size battery very often, whereas if you're driving a Nissan Leaf in the cold, you're probably planning your trips, ruling the car out for some, and doing things like driving at 65mph to get home from work in winter.

We do have to think about range anxiety in our bikes, because many bikes can't easily carry a lot of battery. Think about all the dual suspension guys who are duct-taping stuff to the sides of their bike, lol...

That's where the allcell and the turnigy multistar are comparable options to me. Where can i get the most capacity? what about price? what about power output, which is pretty much always something you have to compromise on..

I know that lipo is not for everyone. I did not write this thread just to thrash allcell in specific. I only wanted to compare it to the most popular high range option to show you that there is a better option for those who are willing to DIY. I've also put forth many efforts to popularize new ebike stuff whenever it was possible for me to do so. I've tried to be fair here and as scientific as possible in order to highlight something that i see as being evolutionary for ebikes - long range at a low cost. It's not written as an attack on allcell. But i knew i'd rustle some allcell fanboy jimmies.. such is life on ES...

neptronix said:

You don't have to dip down to 3v and you never should on a lipo pack, because the chances of you having a perfectly balanced pack that has all the cells rising and falling in sync is like 0.01% 3.5v average is where lipo starts to get real sketchy with voltages. .

Click to expand...

agreed.....but my comment about needing to dip below 3.0v to get the capacity out, was referring to the 18650 cells when loaded at more than 2C.
But... There are still likely to be issues with cell balance as you are working them way past their "linear" discharge voltage zone.

I don't doubt the multistar packs rock. But for sure, I wouldn't point any of the people I sell motor kits to, towards lipo. They aren't ready for the hazard. ES would bewilder them if they read here. They need a reliable pack, and hopefully the allcell setup will be that for them. If they balk at the cost, I still mention pingbattery.

I just bought an allcell pack to replace some of my 4 year old turnigy packs, and I can't wait to have a bike I can charge anywhere again. Employee discount really helped. They are expensive as hell.

I won't use this pack (48v 13ah) with a 40 amps controller, unless I parallel it with some lico, or limit amps to 25 or less. The cargo bike will still run on lico for the most part. But I needed something, easier, less hazard in the house for 50% of my riding. I definitely plan to seldom pull much more than 10 ah from it. Most of the rides it will do are not long enough to need 13 ah. 11 miles to walmart and back for example. That typically takes 8 ah. The flea market is only 3 ah, run the dog, 2 ah, and a long dirt ride about 10 ah.

The cargo bike will still do the longer runs, 30 miles to downtown and back, or long pleasure rides, and it will run on the 25 ah of lico I still have. On a really long ride, I'll load it all on, and have 30 ah of usable capacity. Enough to make it to the next town out here.

The allcell pack will not have the best ratio of c rate, and density of anything I've owned, but it should be a lot nicer than a 16 pound pingbattery was.

there is no reason even the most naive newbie could not use lipo if they are charging with your balancing charger or have a lipo pack with a BMS which i doubt they could build anyway which is why everyone here uses these balancing chargers because they don't have the ability to build a regular pack outa lipo. so naive newbies are no different from the beer swilling veteran boy racers featured here imo.

not only is the waxy matrix heavy to carry around, it still allows the cans to get hot, it just provides a direct thermal contact to a material with a higher heat transfer index than does air cooling around the lipo packs inside the shrink wrap and the cans have to get hot in order to transfer the heat to the wax. it would be better imo to keep the heat from being generated initially. looks like the multistar can do that. pushing more than 2C for long periods of time is kinda difficult anyway.

but conversely, the waxy buildup stores the heat that then continues to keep the can hot for a long period of time after the current surge that has heated up the waxy goop.

the fire risk is from shorted wires and not from overcharging in any case since it requires pushing the lipo up to 4.5V+ for long periods to make it ignite.

I get some awful naive noobies on that chat I work on now. You would not believe...

I do agree, if you are getting your battery all hot and bothered, you screwed up. I would never recommend the Allcell 13 ah pack for anything more than a 22 amps controller. I didn't buy the pack for the wax, I just got tired of watching lico charge in my fireplace because I went to the dollar store 2 miles away. Kind of a pain to do that for such a short ride.

My main point was that one type of battery in discussion (10c) can do a lot more than the other, while the other one might be a hell of a lot more convenient if all you need is 2c. If you need a 40 amps discharge rate, you'd need a big pack to pick the allcell. The 48v 20 ah pack is mighty damn pricy.

I do miss the plug and play of my cellman 20ah 48v amp20 pack but I sure dont miss the extra 4ish kgs now I have these multistars.

Pulling 40-45amps uphill on my headways saw them dive to under 3v a cell and never seem to give me more than 80% capacity. Im getting roughly 3.67v a cell on 10ah 12s or 3.78v on 20ah 12s@47amps (7in1 turnigy watt meter accuracy unknown).

Im a bit stressed about battery location at night and when I find what feels like bubbles on the edges of one of the packs. But im sure Il calm down and enjoy the cells soon with a bit of experience. I didnt go lipo before due to other peoples stories of headaches didnt outweigh the size/weight advantage for me until these cells came up and tipped the balance. Charging from storage voltage (3.79) to full takes me an hour, thats cool. So far Im glad Iv tried them.

You are pushing those cells mighty hard. They would prefer a 2p configuration for 40-50A builds.