New Cyclone LiFePO4 cells

[mrbill]

Has anyone used or tested the new LiFePO4 cells Cyclone is now selling? These are apparently made for Cyclone. Claimed maximum discharge is 10C, max charge is 3C. Cells are same diameter but 8mm shorter than the PSI cells. 330g each. Price is $27 US.

http://cyclone-tw.com/order.htm (Scroll down the page...)

 

[wildnrg]

Yes, I have one 24V 10AH and I've ordered a second one.

They work fine. My motor controller is rated for 24A and I'm using 30A electrical wiring and 45A Anderson connectors.

The Cycle Analyst says that my peak A is 60.1 A which is lower than the 100A claimed by the battery, but I think having a 24A controller might have something to do with the lower peak.

I'm drawing 29A+ on taking off at the lights without pedaling.

 

[mrbill]

Yes, I have one 24V 10AH and I've ordered a second one.

They work fine. My motor controller is rated for 24A and I'm using 30A electrical wiring and 45A Anderson connectors.

The Cycle Analyst says that my peak A is 60.1 A which is lower than the 100A claimed by the battery, but I think having a 24A controller might have something to do with the lower peak.

I'm drawing 29A+ on taking off at the lights without pedaling.

What kind of voltage do you see while you draw 29A from this pack? Is the voltage staying above 24 volts?

 

[wildnrg]

Yes, I have one 24V 10AH and I've ordered a second one.

They work fine. My motor controller is rated for 24A and I'm using 30A electrical wiring and 45A Anderson connectors.

The Cycle Analyst says that my peak A is 60.1 A which is lower than the 100A claimed by the battery, but I think having a 24A controller might have something to do with the lower peak.

I'm drawing 29A+ on taking off at the lights without pedaling.

What kind of voltage do you see while you draw 29A from this pack? Is the voltage staying above 24 volts?

When the battery is more than 50% full I don't see the voltage dropping below 25V even when I'm drawing 500W+ up a hill or taking off. The only time I've seen my voltage go below 24V is after I've used about 7ah of the 10ah battery and even then its only 23.4V. I believe the safe cut off voltage of my batteries is 19V.

According to my Cycle Analyst on today's ride to work, max A was 40A min voltage was 24.5V

 

[fabola]

i ordered a 500W motor kit with this 24V 10Ah battery in the end of November 2009. At the fist time charging, after about 3.5 hours charging the battery start to beep very loudly!! What the heck is going on!?? And it did not stop!! I had to disassemble it and remove the damn buzzer. I contacted the Cyclone sales department to ask if it should work like that? They replied quite fast that if the buzzer starts to beep I should just remove battery from charger, connect it to the bike and run the motor for a while. I tried that, and it worked. I thought what a stupid system! It is very annoying to have to do that all the time, but that is what I have been doing everyday for the last two months.

The bike and kit works just fine, but quite soon I discovered another stupid thing. Then you go to far and battery voltage drops to much the damn battery starts to beep loudly again!! And it does not stop, even if I switch of the power, or remove the cable from the battery!!

Lately I have start realising that the range has been less and less, and now the stupid battery starts to beep almost everyday (at only 8km)!

So I measured the capacity of the battery using and ampere meter and two 12V 20W halogen lamps in series as a load. The result - only 5.9Ah!! That after only two month of use! I start thinking what could be wrong? So I measured the individual cell voltage during charge and discharge. I realized that when charging, two of the cells reach 3.7V much faster than the others that stayed at 3.4V! When one of the two cells reached 3.9V, the beep started. When discharging ,two of the other cells reached a lower voltage much faster the the others. At the time the buzzer starts beeping the voltage of one off these cells was 2.6V,the another one 3.0V and the rest of the cells about 3.25V! So I realised that the cells had become badly unbalanced! Could the BMS-circuit be wrong?? How is it supposed to work?? I found this very good post here http://endless-sphere.com/forums/viewtopic.php?f=14&t=15450 I slowly start to realize what was wrong with my battery. The BMS-circuit in the cyclone battery was just not good enough to balance the battery the first time I charged it. So instead one of the cells reached to high voltage and therefore the buzzer starts beeping. Why? The answer is because the way the BMS is designed. There is only a 20 Ohms resistors for each cell. These resistors is supposed to shunt the cells if cell voltage is above 3.6V. Was they wrong? No they really start shunting, but 3.6V/20 Ohms is only 0.18A and at the same time the charging current is 2A! So what I think have happen is that if the cells where to much different from start, the BMS can not be able to balance the cells, instead it start beeping because of overvoltage on one of the cells. When it starts to beep I was told should remove the charger. Then charger is removed the BMS circuit does not work in balancing the cells, it only works during charging.

So what to do now? I will try to balance the cells myself and hope I can get back the capacity. First I charg the pack until the two cells with higher voltage reached 3.6V. All the other cells are still at 3.4V. Now I remove the charger. Then I charge each of those cells having 3.4V up to 3.6V , one at the time, using a laboratory power supply set to 3.6V and limited current 2A until the current drops below 0.18A. This takes a long time, I'm actually I'm doing it right now!

I really hope this will work the way I expect?? Maybe I will have to to this several times?? Another way could be to manually put a 2ohms 10W resistor to each of the cells that reaches 3.6V during charging.

Another note about the cyclone kit was that the included charger (230V for Europe) was a charger for Li-Ion batteries, not LiFEPO4! But when I measured the voltage is was 28.8V that is the standard voltage for 8 LiFePO4 cells, so they just modified a Li-ion charger without any notes. The charge is marked 24V!

I be back to let you know my result.
Best regards,
Jan

 

[BiGH]

Hi. I'd say get in touch with cyclone again re low capacity. I'd also suggest that balancing the cells yourself might help. But ask their tech department first. They might offer u a solution sorryto hear this. It really sux when batteries don't work well.

i ordered a 500W motor kit with this 24V 10Ah battery in the end of November 2009. At the fist time charging, after about 3.5 hours charging the battery start to beep very loudly!! What the heck is going on!?? And it did not stop!! I had to disassemble it and remove the damn buzzer. I contacted the Cyclone sales department to ask if it should work like that? They replied quite fast that if the buzzer starts to beep I should just remove battery from charger, connect it to the bike and run the motor for a while. I tried that, and it worked. I thought what a stupid system! It is very annoying to have to do that all the time, but that is what I have been doing everyday for the last two months.

The bike and kit works just fine, but quite soon I discovered another stupid thing. Then you go to far and battery voltage drops to much the damn battery starts to beep loudly again!! And it does not stop, even if I switch of the power, or remove the cable from the battery!!

Lately I have start realising that the range has been less and less, and now the stupid battery starts to beep almost everyday (at only 8km)!

So I measured the capacity of the battery using and ampere meter and two 12V 20W halogen lamps in series as a load. The result - only 5.9Ah!! That after only two month of use! I start thinking what could be wrong? So I measured the individual cell voltage during charge and discharge. I realized that when charging, two of the cells reach 3.7V much faster than the others that stayed at 3.4V! When one of the two cells reached 3.9V, the beep started. When discharging ,two of the other cells reached a lower voltage much faster the the others. At the time the buzzer starts beeping the voltage of one off these cells was 2.6V,the another one 3.0V and the rest of the cells about 3.25V! So I realised that the cells had become badly unbalanced! Could the BMS-circuit be wrong?? How is it supposed to work?? I found this very good post here http://endless-sphere.com/forums/viewtopic.php?f=14&t=15450 I slowly start to realize what was wrong with my battery. The BMS-circuit in the cyclone battery was just not good enough to balance the battery the first time I charged it. So instead one of the cells reached to high voltage and therefore the buzzer starts beeping. Why? The answer is because the way the BMS is designed. There is only a 20 Ohms resistors for each cell. These resistors is supposed to shunt the cells if cell voltage is above 3.6V. Was they wrong? No they really start shunting, but 3.6V/20 Ohms is only 0.18A and at the same time the charging current is 2A! So what I think have happen is that if the cells where to much different from start, the BMS can not be able to balance the cells, instead it start beeping because of overvoltage on one of the cells. When it starts to beep I was told should remove the charger. Then charger is removed the BMS circuit does not work in balancing the cells, it only works during charging.

So what to do now? I will try to balance the cells myself and hope I can get back the capacity. First I charg the pack until the two cells with higher voltage reached 3.6V. All the other cells are still at 3.4V. Now I remove the charger. Then I charge each of those cells having 3.4V up to 3.6V , one at the time, using a laboratory power supply set to 3.6V and limited current 2A until the current drops below 0.18A. This takes a long time, I'm actually I'm doing it right now!

I really hope this will work the way I expect?? Maybe I will have to to this several times?? Another way could be to manually put a 2ohms 10W resistor to each of the cells that reaches 3.6V during charging.

Another note about the cyclone kit was that the included charger (230V for Europe) was a charger for Li-Ion batteries, not LiFEPO4! But when I measured the voltage is was 28.8V that is the standard voltage for 8 LiFePO4 cells, so they just modified a Li-ion charger without any notes. The charge is marked 24V!

I be back to let you know my result.
Best regards,
Jan

 

[TPA]

why, when headway cells are $17 each?

http://www.evcomponents.com/ProductDetails.asp?ProductCode=38120S

 

[boostjuice]

These cells Cyclone are selling ARE Headway cells. They even recently changed their description on the website from "Cyclone battery" to "HW battery". Hmm, wonder what "HW" stands for.......

 

[fabola]

So what to do now? I will try to balance the cells myself and hope I can get back the capacity. First I charg the pack until the two cells with higher voltage reached 3.6V. All the other cells are still at 3.4V. Now I remove the charger. Then I charge each of those cells having 3.4V up to 3.6V , one at the time, using a laboratory power supply set to 3.6V and limited current 2A until the current drops below 0.18A. This takes a long time, I'm actually I'm doing it right now!

I really hope this will work the way I expect??

It worked really nice to to do this way!! Some of the cells really needed a lot of extra individual charge - more than 2 hours before the current started to drop. After all cells was charged to 3.6 -3.7V this way I connected the laboratory power supply to the hole pack again. While having the current limit set to 0.2A and maximum voltage to 29.2V and let it be this way over the night for the cell voltages to stabilize. The next day I used the bike for another 8km trip to work and back followed by an charge with the laboratory power supply limited to 2A and 29.2V. I monitor the pack voltage and individual cell voltage very closely. In the beginning the individual cell voltage was very even between the cells, that is good. When some of the cells start reaching 3.55V things happening very fast- now some cells increase there voltage very rapidly until the pack voltage reached 29.2V When this happened the current starts to drop rapidly down to 0.2A in only 5 minutes!! Some of the cells now was as high as 3.74V, but most was around 3.65V. The cell with the least voltage was 3.58V. So I "filled up" this cell to 3.7V by charging it individually with 2A. It took only some minutes until current dropped to 0.2A . This means all the cells and the BMS is working as expected, and the cells seems to have a good balance.

Now I started the capacity test by discharging with the two 20W lamps. I monitor the current and individual cell voltages every half hour. It was again very even voltage between the cells. Then some cells went down to 3.1V I start to measure the cell voltage more often, and stopped discharging at 2.7V.
Capacity now has become 9.53Ah!!! Very good! I'm very happy to the pack working as it should !!

Maybee this is not the ideal way of balancing a pack, but because I monitored it so closely and used a good laboratory power supply I felt I have everything under control even when things start to happening fast at the end of the charge and at the end of discharging.