LI-ion NiCoMn Battery from BMSBattery

[neptronix]

It is supposed to have better energy density, but quality varies widely.

It ranges from 150wHr/kg all the way up to 250wHr/kg.. cells can be anywhere from 0.5C rated to 10C rated.
These are some of the least impressive cells i've seen. What i wanna do is get my hands on what allcell is using.. minus the massive markup.

 

[o00scorpion00o]

Hi Dave,

Maybe the good stuff is being kept for E.V use ?

 

[cwah]

hello, any update on this battery? Is it still performing well?

 

[Rassy]

Haven't had a chance to collect any more meaningful data. Between the winter weather and installing the NuVinci on the trike I've not pushed the battery yet.

When I do use the battery it is consistent with what I reported earlier. Took a nice ride with friends on Sunday and used 8AH and got cold too. Now the wind and rain is back.

 

[cwah]

I also have a NiCoMn battery from Conhismotor. Li(NiCoMn)O2 is their exact description. Since this winter it has lost 1/3 of its capacity. The problem is that I don't know if its a permanent lost or if the capacity will come back when the weather will be better.

I'm also wondering about these batteries calendar life. If they don't loose too much of their capacity over time, it's conceivable to invest in these batteries and sell them back later without too much loss.

 

[neptronix]

I also have a NiCoMn battery from Conhismotor. Li(NiCoMn)O2 is their exact description. Since this winter it has lost 1/3 of its capacity. The problem is that I don't know if its a permanent lost or if the capacity will come back when the weather will be better.

I'm also wondering about these batteries calendar life. If they don't loose too much of their capacity over time, it's conceivable to invest in these batteries and sell them back later without too much loss.

How long have you had it, and how cold is it out there?
How many amp hours is it & what's the max amps of your controller?

Often times the internal resistance of a battery will rise to the point where it will sag a lot, then trip the BMS as a result, when it is very cold. Maybe when the winter clears up you will get your capacity back, unless it has been abused.

 

[cwah]

I had it since 3.5 month (so it's still quite new) and it's around 10 degree celcius outside. It's quite cold, but not that cold.

This is a 36V10Ah battery and usually I draw around 12-13 amps with short burst around 15. But most of the time I'm around 1.2C. The battery however starts to sag at 13 amps when it's half empty. (I have frequent disconnect). But I changed the cables recently (it wasn't doing that initially) so it's maybe bad connections.

This is a small motor at 250W anyway (23 mph max speed), so I don't have much chance to abuse it. :lol:

 

[auraslip]

Actually their discharge specs are all over the place for those packs. I think they don't even know what the real discharge specs are.

As with all discharge/charge rating on batteries, take it with a grain of salt and assume that you'll have to run it at half that.

Nailed it.

 

[tsakis]

Hello there, I have a Problem with this kind of batteries.. I was fool enough not to charge a 48v/12ah one for 2-3 months because of a really important personal issue.. Is my battery ruined? How can I charge it now? 2 weeks ago one friend of mine tested it and it has juice to move the bike (it was fairly charged when I left it).. I assume it does not charge now, only the 1 red led turns on in the charger when plugged.. Please help, it was really expensive to get one here, and I so pissed with myself for forgetting conditioning it while away...

 

[amigafan2003]

@ tsakis

It's more than likely the charger is faulty rather than the battery pack.

What voltage is it putting out?

And what's the voltage of the pack when you're trying to charge it?

 

[neptronix]

Hello there, I have a Problem with this kind of batteries.. I was fool enough not to charge a 48v/12ah one for 2-3 months because of a really important personal issue.. Is my battery ruined? How can I charge it now? 2 weeks ago one friend of mine tested it and it has juice to move the bike (it was fairly charged when I left it).. I assume it does not charge now, only the 1 red led turns on in the charger when plugged.. Please help, it was really expensive to get one here, and I so pissed with myself for forgetting conditioning it while away...

My guess: 1 cell is overdischarged due to a battery "management" system that drains from 1 cell...

Take it apart and test the voltages of each parallel cell group to confirm.
If you have a RC lipo style connector to the BMS, this is easy, you can use a cellLog 8s, cellmeter, etc.

Otherwise you have to take a multimeter to each cell on the balance connector to check..

What your charger is probably doing is refusing to charge starting at a low voltage, OR the BMS is refusing to take power in to protect the pack ( some types of battery chemistry can catch fire if overdischarged and then charged ).

It's possible that you just need a few cells to patch this pack up. Do the test i recommended and see what the result is.

 

[motomech]

Hello there, I have a Problem with this kind of batteries.. I was fool enough not to charge a 48v/12ah one for 2-3 months because of a really important personal issue.. Is my battery ruined? How can I charge it now? 2 weeks ago one friend of mine tested it and it has juice to move the bike (it was fairly charged when I left it).. I assume it does not charge now, only the 1 red led turns on in the charger when plugged.. Please help, it was really expensive to get one here, and I so pissed with myself for forgetting conditioning it while away...

My 48V, 8Ah Li-ion from Ebike C.A. is now R.I.P.
I was shipping the bike home from from a sm. island in the Caribbean where is was working and although I knew it would sit for a while, it actually sat at the origin warehouse for 3 months. I had discharged to about 50% for storage[i probably should have taken it up to 100%, although I doubt it would have helped]and i think the heat, as much as the time period, killed it[bike in box, box in warehouse on tropical island].
Upon arrival, it tested 0 Volts. I dis-assembled it and ck'ed at the parrallel/ cell level, 0 Volts. Dead as a door nail.
In retrospect, I should have sent it Air Freight. The problem with sending it on the "slow boat", is that one can't carry these batteries on an airplane, so the batt. cond. is going to be out of your hands for a while. Or better yet, don't ship Ebikes overseas.

I was more than happy with the Mxus mini-motor on 48V, so I'm interested in how this pack performs for Rassy. My FS bike has an open triangle and the Falcon EV bag fits nicely. I also have one of Johnrobholmes's Mini Stealth[25A version] controllers to try out.

 

[Rassy]

I was more than happy with the Mxus mini-motor on 48V, so I'm interested in how this pack performs for Rassy.

I haven't reported much on the battery since I've not only been restricted by weather but I also rotate my Ping's on what short rides I take.

The battery seems to be doing fine, and I keep it charged, but there are a couple of things that make me wary. The battery voltage seems to hold very steady when not being used for several days. Since it is so well shrink wrapped with whatever BMS it has inside the shrink wrap, I have no way of checking on the condition of the 13 sub packs. After short rides, if the battery is still sitting over 52 volts the charger doesn't even respond. There isn't even a "higher" trickle voltage being applied so obviously no "balancing" is going on. As far as I know there isn't any real balance feature in the BMS. I'm spoiled with the Ping's with the BMS with LED's which give you a great indication that the cells are staying balanced.

Anyway, I'll keep using the battery and report any good or bad issues that develop.

 

[SamTexas]

..., I have no way of checking on the condition of the 13 sub packs. After short rides, if the battery is still sitting over 52 volts the charger doesn't even respond...

That's too bad. That's defective in my view. Have you tried to obtain technical support from the vendor?

 

[Rassy]

Sam asked:

Have you tried to obtain technical support from the vendor?

Sam, the battery is still functioning properly so until it fails I don't think the vendor would consider it faulty. But I agree it may be indicative of a problem. I hope to get a chance to pull 5 or 10 AH out of it in the next couple of days and then see what the charger does. I'll put the Kill-A-Watt ahead of the charger, but unless it doesn't take a charge at all, it will still be impossible to determine the balance.

If it wasn't wrapped so nice I wouldn't mind opening it up to see what's inside. Has anyone here opened one of these up yet to see what the BMS looks like?

 

[Rassy]

Well, here goes again. I lost what I just typed when selecting a picture.

The battery would not take a charge, so first I confirmed the charger was working properly, then cut off the nice shrink wrap. Inside was a neatly done wrap using a sticky on one side foam. The wires were neat and the BMS had a hard piece of material on each side. The wires and BMS were all glued together and took some work with a knife and a plastic scrapper to get it all separated.

The good news, each sub-pack was within 0.01V of 3.91V. Now, after several more weeks, the first sub-pack on the positive end is about 0.04V lower than the others.

I purchased a new BMS that arrived yesterday. The battery now charges properly, but I need to wrap it up to keep some pressure on the cells, since I've heard that under some conditions they may try to expand. I'll be out of town for a couple of days, so more playing next week.

I am concerned that the BMS may have failed because it was so well wrapped within the total battery pack. I plan to create a hole so that I can access the sub-pack voltages where the sense wires attach. Will probably add a hole at the other end of the BMS so air can circulate.

 

[dnmun]

.

 

[Bazaki]

These shrink wrap battery packs are 100% safe ? Ofcourse much better than RC lipo's but safe enough to build an ebike for my family ? Or should I stay with Lifepo4 ?

 

[amberwolf]

These shrink wrap battery packs are 100% safe ?

No such thing; all chemistries could fail catastrophically under one set of conditions or another, almost always requiring a fairly extreme failure of a charger or something to cause the failure...but not impossible, so no such thing as 100% safe.

 

[Bazaki]

I see, but building an Ebike for family without worries to burn down their house......go for LifePO4 ? Still not 100% safe but better then this NiCoMn, or same story ?

 

[Rassy]

Dnmun wrote:

did you measure the cell voltage while you still had the previous BMS installed while it was actually on the charger? is there a charging mosfet and did you check to see if the gate for that mosfet was turned on? the cell that dropped fast was #13, at the top?

I did check the voltage on each side of the charging mosfet, and the voltage was different, charger voltage on the charger side and the lower battery voltage on the battery side. I don't know any electronics stuff, but when I connected one of the mosfet legs to the positive battery voltage via my volt meter, the charger would cycle on and start charging the battery.

Oops, when you said "dropped fast", I double checked, and there was a typo that I corrected. The difference between #13 (I called it the first sub-pack on the positive end), and each of the other 12 was only 0.04V.

@Bazaki: I have read somewhere, probably a vendor's site, that this chemistry is about as "safe" as LiFePO4. And as was mentioned above, any chemistry can fail under the "right" conditions. A friend I was talking to today mentioned how a flooded lead acid battery on his pick-up truck had exploded about 10 years ago.

 

[fgiroult]

I would like to share my experience as well ...after i read & read & read again on this great forum to understand how to build a decent ebike! Now i can tell that i managed to make one So i feel like i need to add my 2 cents.
I bought the same battery from BMSbattery (10 AH version). I read Rassy's review and an other good review from pedelecs.co.uk and i decided to give it a try!
I originally came from a 36v LifePo4 battery from the same vendor but it was incredibly heavy : ~ 7kg on the rear rack is way too much for the balance of the bike, especially with a rear motor setup (9C RH205). So i sold it
This one is 48V 10Ah and it is really small and light : ~3kg - I carry it on the rear rack, i almost forget it. So far i'm quite happy with its performance : according to my wattmeter i can pull 29.5 Amps (no cuts out so far, i'm using a tweeked 27A controller). Starting voltage is 54.37, and resting Voltage after 4.5 Ah used is 48.3V. My daily ride is max 25km so i don't use more than 5Ah per cycle.
So far i have around 30 cycles on it, I'll report back in few months but i hope the performance will last for a few more hundreds of charges !

Fred

 

[999zip999]

What 48v10ah battery ?

 

[Rassy]

I would think that fgiroult is using this battery:
http://www.bmsbattery.com/48v/166-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html
That's a pretty high discharge for a 10ah battery. Will be interested how it holds up. My max discharge on the 20ah battery is just over 20 amps, so a little over 1c. I do use my 10ah Pings on the same trike, so they see a little over 2c discharge.

 

[fgiroult]

I would think that fgiroult is using this battery:
http://www.bmsbattery.com/48v/166-48v-1 ... -pack.html

Yes that one precisely. I hope it will keep on performing well (around 2 C constant & 3C burst)... the pack is not getting warm but these last weeks were very cold here and heat was not an issue !
I found out that 30 amps max is what i need for my daily rides in the city, fast enough to ride safe but not reaching dangerous speeds (over 40/45 km/h).

For my next mountain bike project, i'll need more current to get something fun to ride so i might have to deal with lipos
Fred