BATTERY PROBLEMS

Sorry I don't know the current drawn from the battery. I haven't seen that info anywhere & it isn't in the A2B Metro print out. All I can tell you is that the standard battery used in the A2B Metro is 36V 10A but I've seen it listed as 36V 11.2A as well. I will draw power from the higher 4.1V cell but what about the cells that are 3.3V what will happen with them if I don't top them off separately. Someone suggested I should use A RC 4.2V charger. That's why I asked about any recommendations for buying a charger. MARK???.
 
Sorry if we are coming off a bit harsh here, but sometimes the truth is harsh. I really think you paid for a battery with some bad cells, live and learn. They sag under load, and the bms shuts off.

You don't have to go spend money on a charger, but I do recommend having one of the inexpensive 50w ones around if you are into EV's or other battery stuff. They can be damn handy.

You can help that battery balance faster, by simply rigging a car turn signal light bulb to two wires, and discharging the highest voltage cell down to the same level as the others. Then put it back on the charger, letting all cells get more charge. The one high cell turns off the bms charging for awhile. Or, just put it on the charger for a week or so. Less of course, if it's not so bad out of balance.

Nothing to lose by balancing it up, and seeing if that helps.

The other educational thing you can do, is go to You tube, and watch a vid on how to test cells for internal resistance. You'd need some tools for that, but nothing real expensive. The light bulb, or a small motor can be your discharger. Testing resistance may pinpoint a single cell that is much worse than the others.

My guess is that you will find that all the cells are toast, with no capacity and high resistance. :cry: 300 cycles is an old battery for that chemistry. Even lifepo4 can be killed with 250 cycles, I did it.
 
Mark??

Have you contacted the person you bought the battery from?? What do they say??

If they promised you 1000+ charges and you only got 300 then call them out on that!
 
Well fellow " Spheroids " after drawing down the power on the highest voltage cell and then re-charging the pack all the other cells are now at between 4.0 V > 4.02 V except for the original high cell that still has the highest charge of 4.12 V. Should I ( A ) keep on de-charging the high cell to try to increase the charge in the other 9 cells. Or ( B ) leave the pack on charge for a Week even though the green light is on. Or ( C ) buy a RC LiFe charger to see if the low cells can be charged up. Or forget it and call the whole thing off & by the way has anybody got some cheep LITHIUM ???. MARK???.
 
I'd do the easiest thing first. Leave it on the charger and check it every 24 hours for improvement. If you see improvement leave it on until it doesn't go any higher. and then test it.
 
MARK??? said:
but what about the cells that are 3.3V what will happen with them if I don't top them off separately.
Click to expand...

Where did they come from? Have I missed something like I normally do? In your second post you had nine in the 3.9s and one at 4.1v

MARK??? said:
.....which are in a 3 X 3 X 3 X 1 cell configuration. Going top to bottom per cell pack the left to right the voltage measured 3.98V - 3.92V - 4.10V X 3.97V - 3.96V - 3.97V X 3.97V - 3.93V - 3.96V X 3.93V cells.
Click to expand...
 
Now you've got me confused d8veh unless you actually found my lost post then I apologize. The one you mention listing the Voltage cell by cell do have the low value cells listed but I have the decimal point in the wrong places. It's possible that I made a reading whilst the charger was on, like I did this morning. Something interesting came from this because it showed me something new. When I checked the charges ( not whilst on the charger ) the High voltage cell had changed position in the battery pack. Probably because of a mistake I made with de-charging of the original high cell. I was using a Cree 5000 lumn light to bleed off the original cell but forgot to check it for too long & it had now become the lowest charged cell. Do the power supply for chargers make a whining noise ???. Now the highest cell is first in the pack instead of third cell & it is at 4.12V & the lowest charged cells are at 4.01V. MARK???.
 
If playing doctor with the pack and it's cells you have to sit and watch what is going on. Sit. If you go have a beer and turn on the T.V. ect. you will forget.How do we know ? Easy way to leave it on the charger. Next easy way bring down the high cell like you did but don't go far or go at all. Don't go over 4.2v per cell never ever. People have put a cell phone charger on one cell. But it will not stop at 4.2v and cook the cell. I know you will walk away. We have all done it. Maybe someone could chime in with the controller info about the amps it demands from the battery. Is your other battery on the bike charged ?
 
Can anyone tell me which type of cell these are please > See Pics. I've now bought a charger as recommended > See Pics < to top up the low cells & need to know what setting to use on recharge LiFe / LiPo Etc . I was sold this battery pack as a LiPo Golden Motor battery It's a 3 x 3 x 3 x 1 cell 36V 12A pack but other spheroids comments have given me doubts about these things. Also does anyone have any experience with & can make recommendations about using this charger ???. P.S. Does anyone know why I cant upload more than 3 photos & then to be able to change the ones that the software deleted ???. Thank You MARK???
 
i think your original charger was the correct one. this is a 10S limn2o4 pack and they are just more prone to having short life spans than the lifepo4 but it should still wok ok.

if you wanna use that balancing charger you can set it up for what they call lilo which is low voltage lipo charging where it charges to 4.15V/cell on each channel. or you can use the regular lipo 4.2V/cell program too.

the balancing charger is just like a regular charger with a BMS built in. but in a balancing charger the BMS and charging voltage is digitally controlled by a microprocessor inside the charger.

a regular BMS is set to a specific voltage, not resettable, and your original BMS did seem like it was effective in balancing the pack. the cell voltage will drop quickly on older cells like this as soon as it is off the charger so that is not a problem itself.

you do wanna keep the BMS on the pack since it protects the cells from being over discharged. there are a lotta people who are just opposed to using a BMS and so they try to talk people into following their own opinions.

it may be that the BMS is just cutting out for LVC low voltage cutoff because the internal resistance inside the cells has climbed high enough to make the cell appear over discharged to the BMS which shuts down the output mosfets and turns off when the drop in cell voltage down to 2.1V is detected.
 
I've just seen a video on you tube about altering the settings on a ( IMAX B6AC+ charger) specifically about the Capacity cut off settings. The default is 5000mAh My battery is supposed to be 37V 12A. Does this mean that the Capacity cut off should be re-set to 12000mAh. The demo also states that the re-charger should be reset for the Amperage of the battery cell. So should I have the charger set on LiPo 12A 3.7V. Thanks again MARK???.
 
Well it seems that you've all gotten bored with answering my posts or there's an unwritten rule about not going beyond 2 pages. I balanced all the cells to 4.08V & put the pack back on the A2B Metro. It took of really well, I turned right to go up the hill & it cut out F***. Since I still have charge in the main battery I used that to go up the hill. Once I had gotten to the flat section again I switched the B battery back on & away I went with no problem. I thought " it must be what I've been told about load on the battery " I kept thinking that until I kept going up the steepest hill near my home without a problem. Now I'm thinking WHY ???. I was stopped for 20 Min then headed home. At the top of the hill there's another flat section where on the way back I didn't think that that would be a problem I started back but it cut out again. I turned the bike to the A battery circuit till I got to the downhill again then went back to the B battery all the way back to & past my home to the bottom of the fist hill I told you about. I turned the bike around & it went up the hill again no problem. Interesting ( to me anyway ) I then decided to run the bike without a load to draw down the charge in the battery. So I did that for 1/2 an hour then recharged it using the original charger which turned itself off at 40.09 V. I took it out again turned to go up the hill & it cut out again. So for some reason it won't take a load on the battery unless it's been for a short run fist ????. I still need advice about what settings to use with the IMAX B6AC+ dual charger as it's instruction manual is mostly about RC charging. So if anyone knows someone else who does know their shit can you forward this post on to them. About the rest any ideas,thanks MARK???.
 
Intermittent problem suggest a loose or bad connection(s). That's assuming your BMS is rated for the max load you put on it, and that none of your 10 batteries are sagging to a point that the bms cuts it off.
 
Here they are 999zip999 . After I recharged the battery the reading was 41.26V. With the motor running in the stand the watt meters readings were 117Ah 5.1Wh 29.96Ap 38.80Vm & 901.2 WP if the readings are different under load will have to wait till I relocate the watt meter to the handle bars for me to see it whilst riding. Thanks MARK???.
 
38.8v seems like a lot of sag for a fresh battery and the motor at no load.

You'll learn a lot by watching it while riding up that hill.
 
to find the cell with high internal resistance you have to use a bulk charger and not the balancing charger.

use the balancing charger to charge them all up to the same voltage and then discharge the battery into a big load and compare cell voltages as it drains down.

you should see one cell drop more than the others in voltage under load. say instead of 3.21 under load like most of them there is one cell that reads 2.97V at the same time. or only 3.12V say. but you should be able to figure out which is filling up first and stopping the charging.

so to find the high resistance cell you can bulk charge the pack and the cell with high resistance will climb up in voltage to the HVC first and far ahead of the others. if you started from a balanced level.
 
My rc charger gives voltage of all cells any time it's connected with the balance leads. Charging, discharging, or just sitting there doing nothing.
 
I have the Thunder 1220 balance charger. It tells me voltage and ir at both the battery level and cell level when charging. I have to use the menu system, get to the right screen, and scroll through the cells. But it does it. Balance charging usually results in cells that are to within 0.005v of each other.
 
I can't do balanced charging because there are 10 cells in the battery pack & the charger only does 6 cells max + wrong connectors. The battery pack is a 36V 12A I think LiFe ??? What I don't know is how long to leave each cell on charge for & at what amps to set the charger to. I can alter the capacity cut off from the default 5000mAh & charge at a maximum setting of 5A . But do I need to change anything ???. The default LiPo charge setting is 1.8A at 3.7V. My original factory charger is 42V x 1.8 A. I know that I've got a problem with either a battery cell or the BMS. To stop it cutting out I either have to get up to speed then change to the spare battery or start of going down hill for it to keep running, then it will keep going up hill. The spare battery recharges to 41.04V but totally cuts out around 40V. I'll have to de-box the cells again & check the individual cells to see what's Watt. Thanks MARK???.
 
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