LI-ion NiCoMn Battery from BMSBattery

[neptronix]

Yeah, but the BMS is on the NMC side.

Without BMC the NMC battery would have higher volumetric density. They're also cheaper.

I'm just wondering how that extra payment on the lipo worth it. They zippy compact haven't been tested by a members. Maybe it has very short cycle/calendar life.

Most BMSes are well under 1lb. When you're talking about a 20AH, 48V pack, the cells are the majority of the weight. Have you ever picked up a BMS before?

The cycle/calendar life of the NMC is also unproven. I think they claim 500 cycles, but with a BMS that kills 1-2 cells in a short period of time, and the fact that the pack comes with unmatched cells, how many cycles do you really think you're gonna get out the entire pack? not much... and when a cell dies, where are you going to get a replacement? I don't see replacement cells on BMSBattery's site.

You don't necessarily need zippy compact. Even Turnigy 20C is good in terms of density.
People have stretched the turnigy and zippy batteries to 600 cycles..

But if cycles are what you want, you want lifepo4. That's at the expense of your energy density, but it is a greater value, for sure!

 

[o00scorpion00o]

I would hope NMC lasts much longer than that is Nissan/Renault will be using it in 2015 ?

 

[neptronix]

scorpion.. i do doubt they're using bmsbattery's cells

If you ever read some NMC spec sheets... well, they vary widely in every way. There are the Dow Kokam, which will do thousands of cycles, and can come in lighter than RC Lipo with discharge rates that are halfway decent at 2-4C..

Then it goes all the way down to.. worse than RC Lipo in density.. under 1C discharge.. 500 cycles or lower.. and poor quality, even poor safety.

The cells BMSBattery are using are at the lower end of that spectrum.

 

[cwah]

Neophyte seems to have good results with these cells. 6 months without any capacity loss? That's very very good.

 

[o00scorpion00o]

scorpion.. i do doubt they're using bmsbattery's cells

If you ever read some NMC spec sheets... well, they vary widely in every way. There are the Dow Kokam, which will do thousands of cycles, and can come in lighter than RC Lipo with discharge rates that are halfway decent at 2-4C..

Then it goes all the way down to.. worse than RC Lipo in density.. under 1C discharge.. 500 cycles or lower.. and poor quality, even poor safety.

The cells BMSBattery are using are at the lower end of that spectrum.

Good job then Nissan and Renault will be making the cells themselves so!

Nissan will be making the batteries in the U.K in 2015.

 

[neptronix]

scorpion: cool.. your area could use that kind of work. Maybe one day we'll make a battery or two here in the US..

cwah: We'll see how it goes over the long term. Stuff from BMSBattery ( and many vendors like them ) is hit / miss. No quality control before they ship it out.. you are the QC

 

[Neophyte]

I have two kits currently.

An eZee and a BMC.

Both installed on a Giant platform.

Seen here...

http://www.giant-bicycles.com/en-ca/bikes/model/sedona/9786/49386/

My two NCM packs I switch from one bike to the other as needed. Until I buy two more packs which I'll do soon.

In use I fully drain the packs about 30 percent of the time [ distances approaching 200 km ]. Daily average is in the area of 30 Ah used. And I always recharge immediately upon arriving home and, again, there's never been a problem.

The longest the packs have remained unused following being fully recharged is three days. The CA voltage reading, thereafter, still at 53.8V. My rarely used eZee LiMn pack doesn't fair as well when left unused.

Pack seen here…

http://ebikes.ca/store/photos/B4810LiM-EZ_Kit.jpg

As for C rate?

I set the CA current limit to 20A to remain in line with the pack's continuous discharge spec...

[ Maximal Continuous Discharge Current: 20Amps. ]

Despite the maximal spec...

[ Maximal Discharge Current: 40Amps. ]

Note...

eZee kit controller [ 20A ]
BMC kit controller [ 25A]

48V and 20A at WOT under ideal riding conditions without pedalling...

eZee : 40 km/h

BMC : 48 km/h

Again, no issues with the packs. Having performed flawlessly. Well constructed complete with protective padding. The included chargers functioning 100 percent.

And no major issues with BMSBattery as a company nor with any of the staff.

Will definitely continue to give the company my custom.

And, hopefully, we'll soon be seeing on the market packs hosting some of these claimed anode/cathode, etc. advancements that will, supposedly, yield energy densities up to ten times what we're talking about herein.

You just never know!

 

[o00scorpion00o]

scorpion: cool.. your area could use that kind of work. Maybe one day we'll make a battery or two here in the US..

cwah: We'll see how it goes over the long term. Stuff from BMSBattery ( and many vendors like them ) is hit / miss. No quality control before they ship it out.. you are the QC

Good for the U.K al right, I thought I saw somewhere where they were to build the leaf in the U.S ?

 

[cwah]

I have two kits currently.

An eZee and a BMC.

Both installed on a Giant platform.

Seen here...

http://www.giant-bicycles.com/en-ca/bikes/model/sedona/9786/49386/

My two NCM packs I switch from one bike to the other as needed. Until I buy two more packs which I'll do soon.

In use I fully drain the packs about 30 percent of the time [ distances approaching 200 km ]. Daily average is in the area of 30 Ah used. And I always recharge immediately upon arriving home and, again, there's never been a problem.

The longest the packs have remained unused following being fully recharged is three days. The CA voltage reading, thereafter, still at 53.8V. My rarely used eZee LiMn pack doesn't fair as well when left unused.

Pack seen here…

http://ebikes.ca/store/photos/B4810LiM-EZ_Kit.jpg

As for C rate?

I set the CA current limit to 20A to remain in line with the pack's continuous discharge spec...

[ Maximal Continuous Discharge Current: 20Amps. ]

Despite the maximal spec...

[ Maximal Discharge Current: 40Amps. ]

Note...

eZee kit controller [ 20A ]
BMC kit controller [ 25A]

48V and 20A at WOT under ideal riding conditions without pedalling...

eZee : 40 km/h

BMC : 48 km/h

Again, no issues with the packs. Having performed flawlessly. Well constructed complete with protective padding. The included chargers functioning 100 percent.

And no major issues with BMSBattery as a company nor with any of the staff.

Will definitely continue to give the company my custom.

And, hopefully, we'll soon be seeing on the market packs hosting some of these claimed anode/cathode, etc. advancements that will, supposedly, yield energy densities up to ten times what we're talking about herein.

You just never know!

Thanks for this feedback. Now with Neptronix comments, I don't know anymore toward which battery I should go :lol:

 

[neptronix]

Some people actually have good luck with BMSBattery and their products.

I've heard too many horror stories about that company on my time in this forum to recommend them.
Do your own research and decide whether or not you want to make a transaction with that company.

 

[aaronlim]

I just received my 48V15AH battery. It came 53.8V fully charged.

I have one problem with it. After riding around for about 15km, i measured the voltage and its 49.4V, i charge it up again but this time it charges for only 5 minutes and cuts off at 49.7V

Do I have a faulty cell in the pack? Or is the BMS cutting off too early? The charger voltage is 54.6V, will i damage the battery if i carry on charging it to try to balance it? Can I discharge the battery completely and charge again to get it back to 53.8V?

 

[Racer_X]

aaronlim, I would play with the charge connectors, I have had experience that sometimes it is does not make a solid connection then it stops charging. Your pack should charge up to 54V+. Since it is new I doubt very much it has anything to do with the BMS or out of Balance issue.
Good luck and let us know how it went.

 

[dnmun]

.

 

[Racer_X]

dnmun, I believe It is LI-ion NiCoMn NOT LifePo4. My 48v BMSbattery LI-ion NiCoMn battery charger is set at 58.4V. When my pack is fully charged it reaches 58.4V then goes down to around 58,2V.

 

[Rassy]

That is similar to my experience. The battery arrived fully charged and seemed to be fine for a couple of cycles. Then the battery quit charging. I eventually opened it up to see what was happening, since the charger output was normal. It appeared that the charging "fet" on the BMS was either stuck open or not getting a signal to close. I just purchased a new BMS and everything has been fine since. BMSBattery should have replaced the BMS for free, but some time had passed and I didn't want to get into the hassle of returns etc.

At first I had the same thought you expressed, and ran it down further to see if it would then charge. Didn't help. I did make a temporary pigtail so the charger could be hooked up to the discharge wires with the proper polarity. That allowed me to "bulk" charge the battery, but there was no way to get at the 13 individual cell wires to check the balance without opening up the shrink wrap.

Good luck Aaronlim. Let us know what you do.

 

[aaronlim]

dnmun, it is a 48V15AH LI-ion NiCoMn Battery.

racerX, I played around with the connectors and confirm its not the problem.

Rassy, my case is different because mine will charge, but yours won't, just that it will cut off too early. After several times of using a little of the battery, i plug it the charger it charges, but when it reaches 49.7V it will cut off no matter what. Does this mean by battery is now a 9AH(Assuming i used up 6AH from 53.8v) battery instead of 15AH? This is so frustrating.

 

[Rassy]

Here's one wild guess, but you will need to remove some of the shrink wrap to verify it. One of the cells may be reaching HVC too early, i.e. badly out of balance.

Of course if something is wrong with the BMS you will need to get access to it anyway.

On my 20AH battery the BMS is in the upper corner where the wires all come out. If I was to do it again, I would just make an access flap in that area instead of removing all the shrink wrap.

Good luck.

By the way, those BMS's are programmable, and maybe they set something wrong. Have you tried to check out the problem with BMSBattery?

 

[aaronlim]

Here's one wild guess, but you will need to remove some of the shrink wrap to verify it. One of the cells may be reaching HVC too early, i.e. badly out of balance.

Of course if something is wrong with the BMS you will need to get access to it anyway.

On my 20AH battery the BMS is in the upper corner where the wires all come out. If I was to do it again, I would just make an access flap in that area instead of removing all the shrink wrap.

Good luck.

By the way, those BMS's are programmable, and maybe they set something wrong. Have you tried to check out the problem with BMSBattery?

If that's the case, if i used the battery to LVC, it will all charge back up to 53.8V again?

I'm in the process of asking BMSbattery but they seem clueless, Jack liu says he will check with the manager whats wrong because he is not sure either.

 

[Rassy]

If that's the case, if i used the battery to LVC, it will all charge back up to 53.8V again?

I don't think so. at LVC the high cell would still be much higher than the one that tripped LVC, and would again reach HVC ahead of the others. Remember, this is all just speculation.

As far as I can tell, the BMS on these batteries does not balance the pack like the Ping BMS does, so if it is out of balance you would have to manually balance the 13 sub cells (parallel groups). BMSBattery should be able to explain how their BMS works in regards to balancing.

I'll give my opinion of my battery again:

The price and weight were good, but the BMS seems to be a poor design and unreliable. I also don't like how the voltage drops (like SLA) throughout the discharge cycle unlike LiFeP04 that holds at a fairly constant voltage until near the end.

 

[aaronlim]

Judy from BMSbattery told me there is a reset on the BMS that I can try.



Is that a button that I can press? What she didnt say is what would resetting the BMS do...will all the HVC LVC settings be blank?

I haven't cut open the battery yet i want to try one discharge to LVC before i am sure there is a problem with the battery

 

[dnmun]

.

 

[Rassy]

Dnmun, I agree on the charger voltage for these batteries. The charger that came with mine goes to about 54 1/2 volts, same as Aaronlim said his does. Maybe some of these batteries have 14S instead of 13S?

Aaronlim, I don't have a clue what "resetting" the BMS would do, but suspect you are right that it would then have to be reprogrammed which takes special hardware and/or software to do. Don't think going to LVC will help, but it shouldn't hurt either.

 

[dnmun]

.

 

[Rassy]

did aaron ever list the cell voltages on any of these threads?

dnmun, that's what aaron is preparing to do next. The problem with these batteries is the BMS is completely wrapped inside the shrink wrap, unlike the Ping batteries where the BMS is external to the shrink wrap. Just like aaron, I really hesitated to start cutting into the pack when I had my BMS problem, but there is no other way to figure out what is wrong.

 

[aaronlim]

i have run the battery on my free standing magicpie 3 for almost 5 hours for it to reach 44V before either the controller LVC cut off or the BMS LVC.

On the BMSbattery website it is listed the LVC to be 35.75V. Isn't that too low? That would mean 2.75V per cell before the BMS cuts off.