MJ1 vs 30Q for my needs?

[Rizeblader]

Hey guys,

Been reading and trying to figure out which would serve my purposes better? Have a 1000W Bafang geated rear hub motor. I've ordered a Sabvoton 45amp controller, hoping to test and see how it goes but would like to pull 25 to 40 continuous amps, pulling 50 perhaps max.

Controller for reference
https://hallomotor.com/collections/hallomotor-ebike-controller-ecu/products/hallomotor-sine-wave-36v-48v-60v-72v-1100w-2200w-45a-ebike-programmable-intelligent-controller

It seems with some cells, they have less voltage sag and even though they might be overall less ah, they might be the same as a battery with more ah due to how they provide power at higher draw?

With that said, which one would you recommend?
https://bicyclemotorworks.com/product/52v-17-5ah-lg-mj1-lithium-ion-e-bike-battery/

Vs

https://bicyclemotorworks.com/product/52v-15ah-samsung-30q-lithium-ion-e-bike-battery/


My bike currently has a Reention Dorado 48V, 19ah battery. I will probably leave the battery disconnected and use it as my backup battery since it's part of the frame and tune down controller amp draw to suit this battery.

 

[spinningmagnets]

$500 52V (5P, 10A X 5 = 50A) 17.5ah LG MJ1

$400 52V (5P, 15A X 5 = 75A) 15ah Samsung 30Q

Both packs will easily supply the 30A max that the stock BBSHD draws. They are both the same physical size. Personally I would get the cheaper pack (30Q), because I am surprised there is that big of a difference. If it was only $50 difference, I might get the other pack with the longer range. The extra range is small, so no big deal, but...it's always good to have. One side benefit of the 30Q pack is that later it can be used for a hot-rod hubmotor, if you ever want that...75A peak is a lot...

 

[john61ct]

Not 30Q even if half the price


LG M36 aka MJ1 is top notch.

SONY VC7, Samsung 35E, both comparable, if either were available at say 20% lower delivered price per kWh

Note these are all top **energy** density, not highest C-rates

1C continuous, maybe 3C peaks for short bursts, will last a good long time if treated well.

old school Panasonic NCR18650B not quite as good but still better than most if you see them at say 30-40% lower per kWh than those above.

 

[goatman]

heres okashira doing a cycle test of 30Q at 7amps, from 4.05v to 2.5v which is kind of abusive once you discharge below 3.0v
id go 30Q. kind of matches up with your 5p at 35 to 50amp want

https://endless-sphere.com/forums/viewtopic.php?f=14&t=68556&hilit=okashira+30q&start=100#p1143649

 

[john61ct]

30Q are fine one at a time, but they are not consistent QA

over time a certain number out of a large pack goes bad

in a solderless no-weld where you are easily able to atomize and rebuild the packs replacing the "weak links", not so bad

but in a welded pack, what a PITA

 

[goatman]

i just think if you run the 30Q the way its made to be run, theres nothing wrong with them

take chicago eight months of the year its less than 20 celcius outside, if you run a 30Q between 5 to 10 amps it can get upto a temperature where it can provide its best performance. run a 30Q at a low amp in a cooler climate????????

anyone have a cycle test of the mj1 at 7 or 10 amp discharge?

 

[john61ct]

No, 30Q's poor QC and inconsistent longevity has nothing to do with any treatment factors like temperature, it's a faulty manufacturing process.

As stated, if your use case can handle such inconsistency then maybe it's not a dealbreaker, but

a welded pack of 50 cells or more, 30Q would be a stupid choice.

These facts have been laid out across many threads, documented by trusted and skilled members in several forums.

And no, I'm not wasting time finding the threads for you, plenty of solid testing threads out there too, GIYF

 

[goatman]

in other words there isnt a 7amp cycle test of the mj1

 

[Rizeblader]

in other words there isnt a 7amp cycle test of the mj1

I'm not a battery expert, as you can tell. One of the sites I used during my research had this test shown.
https://lygte-info.dk/review/batteries2012/LG 18650 MJ1 3500mAh %28Green%29 UK.html

 

[goatman]

in other words there isnt a 7amp cycle test of the mj1

I'm not a battery expert, as you can tell. One of the sites I used during my research had this test shown.
https://lygte-info.dk/review/batteries2012/LG 18650 MJ1 3500mAh %28Green%29 UK.html

link didnt work, if its this one
https://lygte-info.dk/review/batteries2012/LG%2018650%20MJ1%203500mAh%20%28Green%29%20UK.html

youll see mah of about 2250 at 3.2v/7amp discharge. if you start going over 7amps with alot of batteries they dont fair well under life cycle testing

Andy kirby was playing with the bosch 36v 6ah batteries, theyre 30Q

https://www.youtube.com/watch?v=CmvZcRGhjZk

his atv electric quad

https://www.youtube.com/watch?v=w8A1vyM2-r4

if you are pulling 35 to 50 amps thats 7 to 10 amps/cell id go 30Q. i wouldnt run a 30Q at 5amp max in a cooler climate it needs to run warm and higher amps will get pack temps up. 25r and 40T like to run warm in the 30 to 40 celsius pack temperature, good power and good mah

 

[Pajda]

anyone have a cycle test of the mj1 at 7 or 10 amp discharge?

Of course we have :wink:

Those cells have quite different parameters and so their operational life depends on their usecase. Unfortunatelly Rizeblader (and many others) give us not enough informations. From the information about using 45A controller/ 1000W motor only we can say that both battery packs will not immediately burn. We definitelly need to know the average battery current/power draw in realworld use of your application. This value can be measured or at least simulated/calculated. The good guess for an ebike with 1000W motor is 200-400W (25-40km/h) average. If this is your case then you need 1C continuous discharge cells and MJ1 is your choice for a long service life. If you really need a 1000W (3C) continuous then MJ1 is not applicable. It will work but up to ca 300 full cycles only.

30Q can do 3-5C continuous, but personally I will not recomend this particular cell due to the above mentioned build quality and overal poor cycle life up to 500 full cycles.

 

[goatman]

anyone have a cycle test of the mj1 at 7 or 10 amp discharge?

Of course we have :wink:

Those cells have quite different parameters and so their operational life depends on their usecase. Unfortunatelly Rizeblader (and many others) give us not enough informations. From the information about using 45A controller/ 1000W motor only we can say that both battery packs will not immediately burn. We definitelly need to know the average battery current/power draw in realworld use of your application. This value can be measured or at least simulated/calculated. The good guess for an ebike with 1000W motor is 200-400W (25-40km/h) average. If this is your case then you need 1C continuous discharge cells and MJ1 is your choice for a long service life. If you really need a 1000W (3C) continuous then MJ1 is not applicable. It will work but up to ca 300 full cycles only.

30Q can do 3-5C continuous, but personally I will not recomend this particular cell due to the above mentioned build quality and overal poor cycle life up to 500 full cycles.

thats what im noticing is when you go over 7amps upto 10 to 15 amps/ cell you might want to go samsung, i kind of think of 2c as a cutoff for a cell like mj1 if im thinking of what cell to use

im going to do a 30Q test to see if its running a 30Q at 1c that kills it because it cant get upto temperature, i know what your saying, are people still reporting pack failures on 30Q? you would think samsung wouldve fixed the issue or stopped selling them.

 

[Pajda]

Samsung 30Q feature is that it wears fast with the very little impact of discharge(charge) rate or DoD. If I should be more specific the wear level when cycled at 1C or 3C at 100% DoD is practically the same. So with this behaviour it is suited for powertools but definitelly not the traction app (maybe extreme one).

I ran more than 4 generations of 30Q in time under the same "my standard" test 0.5-1C 100%DoD (just because I still do not get why this cell is so popular, because measured data shows that it is a piece of junk in comparison with other competitors) and there were significant inconsistency in the wear level and particularly DCIR rise. Selected LG cells retested after years shows almost the same results.

 

[Rizeblader]

Guys thank you very much for the education and informative replies!

After much more research, back and forth, I was hoping for a Luna battery but they are still out of stock.

I have decided on the EM3EV 52V (14S7P) Hard Case Ebike Battery Pack 20ah using PF cells.

I live in the actual city and need to store my batteries indoors unfortunately. Having dealt with 18650s, LiPos in RC vehicles, I wanted the most safety features. That lead me to EM3EV and Luna.

Unfortunately my calls and emails to the company in the original post went unanswered for quite a while ,(10 days). I understand the pandemic, but wondered as to who/where battery was being built by and any safety features.

I will say EM3EV has been phenomenal and quick with thier email answers and assistance. Luna was good too, but couldn't provide me a restocking date.

I will keep everyone posted how it works out. Thank you again for everyone's time and insight!

 

[eMark]

I have decided on the EM3EV 52V (14S7P) Hard Case Ebike Battery Pack 20ah using PF cells.

Apparently 40 amp Max Continuous Current and 55 amp Max Burst Current were three of the seven cell choices to attract Rizeblader's preferred EM3ev 14S7P use objective. These being: High Energy - Panasonic PF, High Power Samsung 25R and High Power Samsung 30Q. EM3ev rates PF at 40A Max Continuous Dicharge (MCD) and 55A Max Burst Discharge (MBD) in their 52V 14S7P chart of the seven cell choices.

• "[Continuous] Discharge Current, recommended 30A or less (22P), 35A (33G), 35A (MJ1) 40A+ (25R and 30Q)"

Neither Samsung 35E or Panasonic PF are mentioned in the above list ... so how in the world did EM3ev ever arrive at PF having a 40A max continuous discharge rating and a 55A max burst rating in their chart of the seven cell choices (22P, PF, 33G, Mj1, 25R, 30Q, 35E) for their 52V (14S7P) rectangular battery pack ... https://em3ev.com/shop/50v-14s7p-rectangle-battery-pack/

Scroll down to see chart comparison of the three cells that meet his 40A and 55A preference among the seven cell choices for the EM3ev 52V 14S7P rectangular pack. Price begins from $499 and presume PF pack is less than either MJ1 or 30Q. Possibly why he decided to go with PF for price and its [questionable] 40A & 55A rating. The following three cells with a 40A MCD and 55A MBD of the seven cell choices are also shown below for the EM3ev 14S7P pack ...

• High Energy ... PF 20.0Ah 1008Whrs ... 40A Max Continuous Discharge ... 55A Max Burst Discharge

• High Power .. 25R 17.2Ah 0864Whrs ... 40A Max Continuous Discharge ... 55A Max Burst Discharge

• High Power .. 30Q 20.7Ah 1041Whrs ... 40A Max Continuous Discharge ... 55A Max Burst Discharge

Question: How do they figure 40A Max Continuous Discharge and 55A Max Burst Discharge for Panasonic PF when PF's Max Continuous Discharge cell rating is 10 amp compared to 30Q's 15 amp Max Continuous Discharge rating and 25R's 20 amp Max Continuous Discharge cell rating. Even the safe pulse discharge (MBD) rating of 40 amps for 25R is "40A < 5 sec" and "30A < 6 sec. So, how can all three (PF, 25R, 30Q) have the same 40A MCD rating and 55A MBD rating ???

So, looks like it's back to either MJ1 or 30Q with preference toward MJ1. The previous 30Q 136 had problems with self-discharge. So far the newer 30Q 141 cell (2019) hasn't garnered any negative reports. Probably too early yet to know if the newer 141 cell is an improvement over the older 136 cell.

 

[Rizeblader]

I have decided on the EM3EV 52V (14S7P) Hard Case Ebike Battery Pack 20ah using PF cells.

Apparently 40 amp Max Continuous Current and 55 amp Max Burst Current were three of the seven cell choices to attract Rizeblader's preferred EM3ev 14S7P use objective. These being: High Energy - Panasonic PF, High Power Samsung 25R and High Power Samsung 30Q. EM3ev rates PF at 40A Max Continuous Dicharge (MCD) and 55A Max Burst Discharge (MBD) in their 52V 14S7P chart of the seven cell choices.

• "[Continuous] Discharge Current, recommended 30A or less (22P), 35A (33G), 35A (MJ1) 40A+ (25R and 30Q)"

Neither Samsung 35E or Panasonic PF are mentioned in the above list ... so how in the world did EM3ev ever arrive at PF having a 40A max continuous discharge rating and a 55A max burst rating in their chart of the seven cell choices (22P, PF, 33G, Mj1, 25R, 30Q, 35E) for their 52V (14S7P) rectangular battery pack ... https://em3ev.com/shop/50v-14s7p-rectangle-battery-pack/

Scroll down to see chart comparison of the three cells that meet his 40A and 55A preference among the seven cell choices for the EM3ev 52V 14S7P rectangular pack. Price begins from $499 and presume PF pack is less than either MJ1 or 30Q. Possibly why he decided to go with PF for price and its [questionable] 40A & 55A rating. The following three cells with a 40A MCD and 55A MBD of the seven cell choices are also shown below for the EM3ev 14S7P pack ...

• High Energy ... PF 20.0Ah 1008Whrs ... 40A Max Continuous Discharge ... 55A Max Burst Discharge

• High Power .. 25R 17.2Ah 0864Whrs ... 40A Max Continuous Discharge ... 55A Max Burst Discharge

• High Power .. 30Q 20.7Ah 1041Whrs ... 40A Max Continuous Discharge ... 55A Max Burst Discharge

Question: How do they figure 40A Max Continuous Discharge and 55A Max Burst Discharge for Panasonic PF when PF's Max Continuous Discharge cell rating is 10 amp compared to 30Q's 15 amp Max Continuous Discharge rating and 25R's 20 amp Max Continuous Discharge cell rating. Even the safe pulse discharge (MBD) rating of 40 amps for 25R is "40A < 5 sec" and "30A < 6 sec. So, how can all three (PF, 25R, 30Q) have the same 40A MCD rating and 55A MBD rating ???

So, looks like it's back to either MJ1 or 30Q with preference toward MJ1. The previous 30Q 136 had problems with self-discharge. So far the newer 30Q 141 cell (2019) hasn't garnered any negative reports. Probably too early yet to know if the newer 141 cell is an improvement over the older 136 cell.

Wow that threw a curveballs in my plans! I had reiterated my amp requirements to EM3EV and they said the PF cell would work. Now reading the specs your provided, doesn't seem feasible. I don't mind spending the money, as I understand a good battery is paramount. Moreso to me due to performance and safety.

If it were upto you, which battery and charger would you get that you trust?

I was planning on the Luna charger
https://lunacycle.com/luna-charger-52v-advanced-300w-ebike-charger/

 

[john61ct]

Panasonic PF is not really same category energy density as the MJ1, also not great lifespan.

for decent power density though, discharge current up to 3C continuous and 6C peak

Comparable but a bit better Samsung 29E / 29E7

LG M29 much better lifespan

SONY NC1?

 

[eMark]

Panasonic PF is not really same category energy density as the MJ1, also not great lifespan. for decent power density though, discharge current up to 3C continuous and 6C peak

Comparable but a bit better Samsung 29E / 29E7. LG M29 much better lifespan
SONY NC1?

Neither 29E/29E7, M29 nor NC1 are among the available seven cell choices for the EM3ev 14S7P battery pack ... https://em3ev.com/shop/50v-14s7p-rectangle-battery-pack/ (scroll down to see chart with misleading PF rating)

Your recent post is confusing as Rizeblader's apparent usage is more for maximum discharge current than longevity (e.g 29E). 29E is rated at only 2.75A for maximum cont. discharge. Both M29 and Mj1 are both rated at 10A. Are you now recommending M29 instead of MJ1 (or 25R one of the seven EM3ev 14S7P cell choices) for both maximum continuous discharge rating and longevity with max cont discharge apparently being his primary usage requirement.

If so, would be helpful to Rizeblader if you might provide a source for a 14S7P battery pack with LG Chem M29 cells assuming you'd still recommend M29 instead of MJ1 (or 25R) for his ($500) 14S7P pack. His usage requirement seems to be aimed more for Maximum Discharge Current rating. He was apparently misinformed by the midleading info provided by EM3ev that a 14S7P Panasonci PF battery pack would provide the same max cont discharge rating and max burst rating as 30Q and 25R ... https://em3ev.com/shop/50v-14s7p-rectangle-battery-pack/ (scroll down to see chart with misleading PF max cont discharge rating)

Of the EM3ev 14S7P seven cell choices would you recommend MJ1 or 25R for his assumed usage requirement being max cont discharge (as well as longevity) ... MJ1 (10A) or 25R (20A) ? Because MJ1 offers more capacity should we assume it has an advantage in longevity over that of 25R ? Inquiring minds would like to know

 

[john61ct]

I clearly stated those categorical differences, and

no I am not recommending any models in that post, nor any specific models really,

certainly never said anything about EM3EV's offerings,

was just addressing OP's questions (via PM) about PF.

I have no idea where you are getting your "ratings",

IMO that "C rate" aspect of the mfg data sheets are best ignored, and

there is also no generalization possible about longevity from those sources either.

The real-life test results and opinions, as published by Pajda and other trusted expert members are much more objective data.