Search found 2639 matches
- Aug 25 2013 2:21pm
- Forum: EBike Technical
- Topic: "LiPO", another "be careful" warning...
- Replies: 54
- Views: 5067
Re: "LiPO", another "be careful" warning...
No matter if you have a BMS or not, it won't save you from unbalanced cells during a charge. The BMS is similar to an external battery balancer. Some are better than others, but the basic bms that comes with a high voltage 48v pack is a battery balancer. It can only re-balance your cells at a certa...
- Aug 23 2013 12:59pm
- Forum: EBike Build Threads
- Topic: Monzilla - BURNED IN LIPO FIRE AUGUST 11
- Replies: 136
- Views: 20973
Re: Monzilla - BURNED IN LIPO FIRE AUGUST 11
This is not the thread for BMS. That said, YOU ARE STUPID for using BMSes that don't work. How many times do you need to be insulted?dnmun wrote: there are a lot of self righteous people on this board who make it a point to say that using a BMS is stupid.
- Aug 20 2013 1:39pm
- Forum: EBike General Discussion
- Topic: Is there a curse on white bikes ?
- Replies: 19
- Views: 1281
Re: Is there a curse on white bikes ?
Never had a white bike but I'm superstitious. I never leave home without my wallet.
- Aug 15 2013 10:55am
- Forum: EBike General Discussion
- Topic: Amazing Patent 2,5kg 1000watt e-bike conversion kit !
- Replies: 23
- Views: 2651
Re: Amazing Patent 2,5kg 1000watt e-bike conversion kit !
Why bother with the patent application in the first place? If friction drive is truly useful then the 60 years old Velo Solex would still be very popular today.
- Aug 09 2013 3:21pm
- Forum: EBike Technical
- Topic: "LiPO", another "be careful" warning...
- Replies: 54
- Views: 5067
Re: "LiPO", another "be careful" warning...
Just to clarify, I had no intention of using this pack for any other purpose than testing. I was not riding it to get anywhere but just to test the capacity. I wanted to know if it could be recovered by balance charging. It could not. I could, I am sure, have removed the cells that went below, say,...
- Aug 09 2013 1:56pm
- Forum: EBike Technical
- Topic: "LiPO", another "be careful" warning...
- Replies: 54
- Views: 5067
Re: "LiPO", another "be careful" warning...
...the battery capacity was probably a third or less of what it was originally (not surprisingly). I noted with the balance charger that the cells that had the extremely low voltages would very quickly charge up to close that of the "stronger" cells. I placed the pack in a safe location a...
- Aug 09 2013 1:28pm
- Forum: EBike Technical
- Topic: "LiPO", another "be careful" warning...
- Replies: 54
- Views: 5067
Re: "LiPO", another "be careful" warning...
I do not want to start an argument here, but i want to clarify something. I have intentionally tested t he scenario you described with LiFePO4 and consumer LiCo laptop battery. I have built small capacity packs and let them slowly discharged to zero. No dramas at all. In the rare few cases, a few c...
- Aug 09 2013 12:23pm
- Forum: EBike Technical
- Topic: "LiPO", another "be careful" warning...
- Replies: 54
- Views: 5067
Re: "LiPO", another "be careful" warning...
just because you have not personally had a fire, does not mean it's not possible. That's not true. I have had many fires with RC LiCo under controlled testing environment. I have never had any fire with consumer LiCo and LiFePO4. And I have NEVER said that fire is impossible. I always says that all...
- Aug 09 2013 11:45am
- Forum: EBike Technical
- Topic: "LiPO", another "be careful" warning...
- Replies: 54
- Views: 5067
Re: "LiPO", another "be careful" warning...
Just trying to add to the cumulative experience of this community. Certainly, it was not the fault of the battery, ... I have to disagree with you. I have intentionally tested the scenario you described with LiFePO4 and consumer LiCo laptop battery. I have built small capacity packs and let them sl...
- Aug 06 2013 7:50pm
- Forum: EBike Technical
- Topic: What is your watthours per mile?
- Replies: 26
- Views: 3775
Re: What is your watthours per mile?
... At laguna seca we were averaging about 280 wh/mi. What were your average speed? 50mph only requires about 3,500W. At 50% efficiency, that's still only 7,000W or 140Wh/mi. Using the same calculation, 62mph only requires 12,400W OR 200Wh/mi. 4,000+ lb electric cars consume less than 280Wh/mi on f...
- Aug 06 2013 9:08am
- Forum: EBike General Discussion
- Topic: Bicycle headlight with 6x CREE XM-L T6 LED 7800LM
- Replies: 44
- Views: 4005
Re: Bicycle headlight with 6x CREE XM-L T6 LED 7800LM
I experimented with the benchtop DC power supply some more and found that amperage stayed stable near 2.1 amps even when the volts where raised significantly (my PS can go up to 3A). I got up to 17 volts before chickening out. The light did get brighter as the volts went up. I don't think it was tw...
- Aug 05 2013 12:48pm
- Forum: EBike Build Threads
- Topic: Just an odd "bike" seen while riding
- Replies: 11
- Views: 2251
Re: Just an odd "bike" seen while riding
Sounds good. Thanks for sharing.
I spent a few days in Guangzhou in the mid 90's. I was an experience I don't want to repeat again. Macau and Hong Kong were much better for me.
I spent a few days in Guangzhou in the mid 90's. I was an experience I don't want to repeat again. Macau and Hong Kong were much better for me.
- Aug 05 2013 8:50am
- Forum: Battery Technology
- Topic: 18650 cell test: Panasonic vs. LG
- Replies: 53
- Views: 32129
Re: 18650 cell test: Panasonic vs. LG
OK, will do 50 cycles at 1C discharge and 0.5C charge. That's great. I look forward to seeing the results. Just a thought here, not trying change your mind or convince you of anything: Why not do the test at the actual anticipated charge/discharge rate? After all the actual charge/discharge rate is...
- Aug 05 2013 3:45am
- Forum: Battery Technology
- Topic: 18650 cell test: Panasonic vs. LG
- Replies: 53
- Views: 32129
Re: 18650 cell test: Panasonic vs. LG
It says "charging current 1325 mA" which is 0.5C. That's what I expected. 1325/3400 = 0.39C I really hope that Panasonic cell failed due to too high charging current. I do have one more cell, so will repeat the tests some day. I hope so too. Panasonic has a reputation to keep. I would lov...
- Aug 05 2013 3:20am
- Forum: Battery Technology
- Topic: 18650 cell test: Panasonic vs. LG
- Replies: 53
- Views: 32129
Re: 18650 cell test: Panasonic vs. LG
Very interesting data. You're the first individual I know that does a life cycle test. Wow! I have always been interested in the Panasonic NCR18650B cell, but I have also had doubt in mind about this chemistry. Looks like my doubts are valid, based on the result of your test here. Question: Why did ...
- Aug 05 2013 3:02am
- Forum: EBike Build Threads
- Topic: Just an odd "bike" seen while riding
- Replies: 11
- Views: 2251
Re: Just an odd "bike" seen while riding
I figured just as much. How do you get by over there? Are you fluent in the language?
- Aug 05 2013 12:11am
- Forum: Battery Technology
- Topic: Nissan Leaf Cells Test Data
- Replies: 386
- Views: 86080
Re: Nissan Leaf Cells Test Data
The two red voltage curves. With sense wire the voltage is always about 0.10V higher from begin to end of discharge.
- Aug 04 2013 11:40pm
- Forum: EBike General Discussion
- Topic: hypothetical range question..
- Replies: 89
- Views: 4385
Re: hypothetical range question..
swbluto wrote: If he does a lot of long distance trips, I'd imagine he'd develop the stamina to do 15 mph continuous under his own power, thus capable of tripling distance at 30 kph.
- Aug 04 2013 11:34pm
- Forum: EBike General Discussion
- Topic: hypothetical range question..
- Replies: 89
- Views: 4385
Re: hypothetical range question..
That's what everybody says. Most of them can't even do 14mph for 2 hours and that includes young people. Grandma would be lucky if she can finish 10 miles, regardless of hours.swbluto wrote: 30 kph is only 18 mph. My grandma can pedal that fast.
- Aug 04 2013 11:30pm
- Forum: EBike General Discussion
- Topic: hypothetical range question..
- Replies: 89
- Views: 4385
Re: hypothetical range question..
Looks like 1kwh at 30 kph would propel you about 63 miles or 101 km. (48v, 20ah LiFePO4) If you pedal along, you can easily double or triple that, depending on how much you want to work. Double, yes. Triple, no way, not at 30kph. The OP strength (according to him) is 20kph for at least 2 hrs. Meani...
- Aug 04 2013 10:58pm
- Forum: EBike General Discussion
- Topic: hypothetical range question..
- Replies: 89
- Views: 4385
Re: hypothetical range question..
Hmm... Going for speed? Forget all the previous estimates. They were based on 30kph and you doing real pedaling.
The energy needed will at least triple to 1,500Whr at 40kph and NO pedaling for 90kms. Good luck carrying that much low-density LiFePO4 battery.
The energy needed will at least triple to 1,500Whr at 40kph and NO pedaling for 90kms. Good luck carrying that much low-density LiFePO4 battery.
- Aug 04 2013 9:45pm
- Forum: EBike Build Threads
- Topic: Just an odd "bike" seen while riding
- Replies: 11
- Views: 2251
Re: Just an odd "bike" seen while riding
Thanks. So is that portion of China bicycle friendly? Are you on a regular bicycle ride, or an ebike ride?
- Aug 04 2013 9:13pm
- Forum: EBike Build Threads
- Topic: Just an odd "bike" seen while riding
- Replies: 11
- Views: 2251
Re: Just an odd "bike" seen while riding
Interesting. Do you actually see the pedals? What city is that?
- Aug 04 2013 6:03pm
- Forum: Battery Technology
- Topic: Nissan Leaf Cells Test Data
- Replies: 386
- Views: 86080
Re: Nissan Leaf Cells Test Data
That's exactly what I expected to see. What a difference in sag!
That said, I'm still disappointed. I expected this chemistry to hold voltage much better under discharge.- Aug 04 2013 4:56pm
- Forum: EBike General Discussion
- Topic: Electric Bike lawnmower still needs refinement
- Replies: 16
- Views: 1703
Re: Electric Bike lawnmower still needs refinement
What a cool toy!