LI-ion NiCoMn Battery from BMSBattery

I just testeed charging from 44V(LVC) to 49.9V took 2hrs 45mins on a 4A charger before the charger cut off.

2h 45 mins on 4A means i only have 11AH of usable capacity on my 15AH battery. is this normal? On my kill-a-watt meter the charger is pulling 218W to 223W while charging the battery so i believe the charger is working correctly (218W / 4A = 54.5V)

Someone please tell me there's nothing wrong with my battery? :cry: Whats the next step?
 
Aaronlim, I don't think anyone can really tell you it your battery is truly okay or not, at least without looking at individual cell level voltages, etc.

If I were you, and you can live with the 11 or so AH for a while, I would just use it as is and make sure everything is consistent. I still believe some cells are probably out of balance, and until you open it up and manually charge or discharge the offending cells so that everything is balanced you will be stuck with just 11AH.

Did you ever find out if the BMSBattery BMS is supposed to balance? We know the Ping BMS balances the battery, but I suspect the BMSBattery one just does the LVC and HVC protection.
 
Starson said:
Mystery to be solved here, because the 48V 10ah battery has a 2c continuous rating http://www.bmsbattery.com/48v/166-48v-10ah-lithium-ion-electric-bicycle-battery-pack.html
Click to expand...

I like the price $239. What does "shrink tube" mean? Wondering how safe this chemistry (Li-Ion NiCoMn) is in comparison LiFePO4.

I notice they said it is "2p13s 5Ah polymer cells". I suppose that means with the put the p before the s, that it is indicating groups in parallel that are strung in series, as opposed to if they said 13s2p would indicate strings of 2 groups 13 cells in series connected together in parallel??
 
Rassy said:
Aaronlim, I don't think anyone can really tell you it your battery is truly okay or not, at least without looking at individual cell level voltages, etc.
Click to expand...

Ok opened up the shrink wrap and form and here are the results from left to right:

3.81 3.80 3.81 3.80 3.82 3.81 3.81 3.82 3.81 3.81 3.81 3.81 3.82 which makes it about 50V

All cells are well balanced. Qustion is the charger cutting off when its only 3.82V?
 
I'm assuming those are no-load voltages. What do they read when you put a load on teh battery? (say, a 100W incandescent light bulb, or a few of them in parallel)
 
Too bad you had to cut open the battery, but good news that it is well balanced. I don't remember the exact numbers but each cell of my battery was a little over 4 volts.

So my guess is the HVC was set too low when that BMS was programmed, since that was one of the things BMSBattery had to set on my replacement BMS.

At least now you know you won't be hurting the battery at all to use it.

Maybe there's an ES member that purchased the BMS programming kit that BMSBattery sells (fairly expensive, about $100 plus shipping) and you could reprogram your BMS. It would actually make more sense to buy the programming kit then to send your battery back to BMSBattery. I don't know how difficult the kit is to use, but I'd be glad to send you my old BMS to practice with. Of course a new BMS is only $20 plus shipping, but it's a pain to install.

http://www.bmsbattery.com/smart/135-smart-bms-usb-i2c-adapter-programmer-reader-writer-monitor.html
 
Rassy said:
So my guess is the HVC was set too low when that BMS was programmed, since that was one of the things BMSBattery had to set on my replacement BMS.
Click to expand...

If the HVC is set at 50V, then why did the battery come out of the box at 53.8V? I tested the voltage the moment i got it. I then played around with it a little but it was never able to start charging until it was below 50V.

BMSbattery is now telling me to try to reset the BMS by shorting the transistor thingy...I have no idea how to do this. I put a voltmeter on the reset transistor on the BMS and it measures 3.23V even when i have plugged out the battery. I tried using a jumper wire to short it but nothing seems to happen...am i doing it the wrong way?
 
dnmun said:
he is measuring the resting voltage of a fully charged pack it seems. i think i recommended he discharge the pack into a dummy load and find out which cell dies first and he can measure the capacity by running the discharge through an ammeter setting on his voltmeter if he doesn't have a wattmeter or cycle analyst.
Click to expand...

how would that help? it seems now at 3.82V for each of the cells, that there is no problem with them. BMSbaterry told me these cells are 2.75V to 4.2V range. Question is why can't it go past 3.82V when my charger is outputting 54.6V. It stops at 50V no matter what. It should become 4.15V each to make the fully charged battery at 53.8V which was what i got it out of the box. I believe at 53.8V I would be getting the full 15AH of the battery
 
dnmun said:
it would help to find the weak cell that triggers the LVC. i thought that was your problem, maybe you are a different problem, several limno4 battery pack threads floating around now.
Click to expand...

no i'm not having a LVC problem. Its the low HVC problem. I am now suspecting as rassy said i was given a BMS which was programmed for 12S (4.15x12 = 49.8V) which is what i'm getting before the charger cuts off. As to why i got 53.8V out of the box could be because these cells were already fully charged when they built the pack and they didn't bother to QC
 
dnmun said:
adjust the charger voltage up and see if it will give you the capacity you are missing then.
Click to expand...

I was messing around the BMS and connections and then a big spark. Now the output of the battery is 24.5V, I checked the individual cells again and thank god they are all ok at 3.82V.

Guess I have to change the BMS now :(
 
dnmun said:
can you be more specific about where the short occurred? is the BMS now shut down? what is the gate voltage on the output FETs? you may still be able to adjust the charger voltage up to see if that gives you the full capacity.
Click to expand...

I was soldering the positive end of the output (the 3 prong connector) and i think i shorted it accidentally. I think BMS is screwed now as its outputting only 24.5V while the individual cells are ok at 49.8V. I don't know what is a gate and FET?

I wish I had the chance now to adjust the voltage to charge the battery but it just seems too dangerous now with a dodgy BMS. I think i should just send the whole battery back to them and get it sorted. this has been such a bad experience
 
dnmun said:
you shorted the output of the charger or the output of the battery? i have no idea where the 3 prong connector is.

the gate on a mosfet is like the toggle on a light switch. when it is high then the mosfet conducts and when it is low then the mosfet is shut off and acts as an insulator.

do you have pictures?
Click to expand...

I shorted the battery. Now the cells are inputing 49.8V into the BMS, but the BMS is outputting 25V. I have been looking at the BMS for 5 minutes and cannot find any toggle switch.

 
I am considering purchasing a LiNiCoMn battery 36v 20ah

1)$320.00 includes charger, not shipping from BMS....http://www.bmsbattery.com/36v/445-36v-15ah-lithium-ion-electric-bicycle-battery-pack.html

or 2) from allcell for $940 includes shipping and charger with 2 year warranty.... http://www.allcelltech.com/products/ebike ...this is american made and price is almost 3 times as much

Any opinions? Oh yeah this is will power an eZee rear hub motor on my Rans recumbent.
 
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