Search found 96 matches

by avandalen
Apr 07 2012 4:51pm
Forum: Motor Technology
Topic: Smart EBike: Dashboard + Motor controller + Battery BMS
Replies: 166
Views: 50987

Re: EBike Smart Controller (OpenSource) -- let's make it

Hi Jorge, The KU63 costs only about $15 and is not bad, it is small and light and gets hardly warm under load. Building a motor controller is pretty much work, it must have a lot of meaningful extra opportunities, otherwise it makes less sense. -The following extras would be very welcome: -Sine wave...
by avandalen
Feb 21 2012 2:56pm
Forum: E-Bike Build Threads / Photos & Video
Topic: My solar bike
Replies: 56
Views: 9612

Re: My solar bike

hello The advantage I see using the Turnigy charger sans mppt is that it will run with voltages of 10-20V before shutdown. Very close to what I'd expect from the solar cells going from full sun/full or partial shade That is smart. But a MPPT calculates the maximum solar cell power point, the Turnig...
by avandalen
Nov 06 2011 1:32pm
Forum: Battery Technology
Topic: lipo bulk charging safety net
Replies: 12
Views: 1822

Re: lipo bulk charging safety net

What do you mean with bulk charging? Do you have a couple of 12s2p battery packs or one 12s2p battery pack? You need just need a charger and a reliable BMS that protects the cells. I will get a BMS with the BQ78PL114. The statistics can be read out for each cell individually etc. This BMS will becom...
by avandalen
Sep 27 2011 3:51pm
Forum: Battery Technology
Topic: Measuring A123 internal battery resistance again (=10mohm)
Replies: 18
Views: 3343

Measuring A123 internal battery resistance again (=10mohm)

Here is the old topic which is locked: http://endless-sphere.com/forums/viewtopic.php?f=14&t=32211 I measured the A123 ANR26650 LiFePO4 internal resistance again. When I take the temperature and the solder tabs into account, the internal resistance is 10mΩ which is equal to the value in the ANR26650...
by avandalen
Sep 07 2011 12:46pm
Forum: Battery Technology
Topic: Portable lightweight 360W LiFePO4 battery charger
Replies: 27
Views: 5684

Re: Portable lightweight 360W LiFePO4 battery charger

hi albert, Im planning on buying one of these chargers from BMSbattery, I wanted to ask if the Vout is adjustable? Im running 20s lipo now (~82V for 4.1 per cell) but im planning on switching to 24s in the near future. is it possible to adjust to ~98V output? thanks mate sc. Yes, you can adjust the...
by avandalen
Sep 07 2011 6:10am
Forum: Battery Technology
Topic: Portable lightweight 360W LiFePO4 battery charger
Replies: 27
Views: 5684

Re: Portable lightweight 360W LiFePO4 battery charger

Ooops. I made that mistake I orderd a 600w charger but got it initially set to suit my 16s LiFe pack, with the plans to adjust it when I go to a 24s LiFe pack, but it has a 63V cap @ C17 on your schematic. :( Damn. Can I just swap this cap then make the other mods you outlined? Or am I stuffed? Reg...
by avandalen
Sep 07 2011 5:44am
Forum: Battery Technology
Topic: Portable lightweight 360W LiFePO4 battery charger
Replies: 27
Views: 5684

Re: Portable lightweight 360W LiFePO4 battery charger

hi albert, Im planning on buying one of these chargers from BMSbattery, I wanted to ask if the Vout is adjustable? Im running 20s lipo now (~82V for 4.1 per cell) but im planning on switching to 24s in the near future. is it possible to adjust to ~98V output? thanks mate sc. Yes, you can adjust the...
by avandalen
Aug 21 2011 1:27pm
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 23
Views: 6445

Re: Automatic anti spark circuit

I wouldn't say that 50mV voltage drop at 10A is negligible, that's 5W 0.5W power dissipation on a non-heatsinked TO220. That's a lot of heat. But it is a very nice solution for lower power controller! update: corrected the power dissipation, it's 0.5W and not 5W Use the PSMN2R0-60PS (2.2mohm). The ...
by avandalen
Aug 21 2011 1:21pm
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 23
Views: 6445

Re: Automatic anti spark circuit

ambroseliao wrote:Very nice. Can this circuit work for 72v and How much current can it handle? Do you plan on making the pcb and parts available as a kit?

Thanks,
Ambrose
Yes, see my website for the 72V schematic:
Image
by avandalen
Aug 09 2011 2:15pm
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 23
Views: 6445

Re: Automatic anti spark circuit

Forgive my electronics ignorance, but is stuff like the pathway from battery + through R1 and R5 to battery - a common thing for you guys? I realize that it's still only less than .5W for my typical pack charge of 80V when I'm parked, but I only disconnect a few times a year, so a parasitic loss li...
by avandalen
Aug 09 2011 2:13pm
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 23
Views: 6445

Re: Automatic anti spark circuit

I wouldn't say that 50mV voltage drop at 10A is negligible, that's 5W power dissipation on a non-heatsinked TO220. That's a lot of heat. But it is a very nice solution for lower power controller! Yes I know, 10A gives 0.5W power loss (not 5W). Here in the Netherlands the maximum motor power is just...
by avandalen
Aug 09 2011 2:05pm
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 23
Views: 6445

Re: Automatic anti spark circuit

Very nice. Can this circuit work for 72v and How much current can it handle? Do you plan on making the pcb and parts available as a kit? Thanks, Ambrose You can use another power Mosfet for higher voltages. No PCB is required, see image. For currents above 10A it is better to use more power MOSFETS...
by avandalen
Aug 08 2011 6:28am
Forum: E-Bike Technical
Topic: Automatic anti spark circuit
Replies: 23
Views: 6445

Automatic anti spark circuit

Here is an anti spark circuit which works automatically. Just simply insert the connector, no sparks will occur. The anti spark circuit can be built into the battery pack or into the motor controller. http://www.avdweb.nl/Article_files/Solarbike/Motor-controller/Automatic-spark-eliminator-circuit-to...
by avandalen
Jul 03 2011 5:26pm
Forum: E-Bike Technical
Topic: pre-charge resistor on charger?
Replies: 14
Views: 1099

Re: pre-charge resistor on charger?

I have made a lightweight battery charger with a built in anti spark circuit, maybe you can use this? http://www.avdweb.nl/solar-bike/electronics/portable-lightweight-lifepo4-ebike-battery-charger-800g.html Albert Albert, What about cutoff voltage? It would be very nice to have a range there too, f...
by avandalen
Jul 01 2011 2:42am
Forum: E-Bike Technical
Topic: Chinese balancing BMS tested
Replies: 2
Views: 768

Chinese balancing BMS tested

For my solar bike I will use the Capacity cell balancing BMS "AE-LMD17 REV A1" from China. See here for a complete test: http://www.avdweb.nl/solar-bike/electronics/bms-ae-lmd17-rev-a1.html http://www.avdweb.nl/Article_files/Solarbike/BMS/Capacity-balancing-BMS.JPG http://www.avdweb.nl/Article_files...
by avandalen
Jun 19 2011 2:01pm
Forum: E-Bike Technical
Topic: Calculation of front fork stress due to hub motor
Replies: 28
Views: 6008

Re: Calculation of front fork stress due to hub motor

I made a prototype of a strong torque arm for the carbon front fork. The strength was tested on an old carbon front fork and with a weight on a long lever. I was not able to damage the torque arm or the front fork. http://www.avdweb.nl/Article_files/Solarbike/Images-mechanical-issues/Hub-motor-torqu...
by avandalen
Jun 06 2011 3:12am
Forum: Battery Technology
Topic: Encapsulated capacitive balancing BMS inside view
Replies: 0
Views: 420

Encapsulated capacitive balancing BMS inside view

The electronic of my LiFePO4 capacitive balancing BMS was encapsulated, so I wanted to figure out what's in it. By heating the epoxy it will be soft and can be removed, though with great difficulty. Unfortunately, the IC markings are gone. It seems that the BMS is built with conventional ICs and is ...
by avandalen
May 16 2011 9:54am
Forum: Battery Technology
Topic: Portable lightweight 360W LiFePO4 battery charger
Replies: 27
Views: 5684

Re: Portable lightweight 360W LiFePO4 battery charger

I have the 900W version that am going to use for a 30S Lipo bulk charging. I got the 120V version but would like to be able to trim the voltage to better suit. 125V would be preferred. Also like to be able to bulk charge 24S so a voltage of close to 100V would be great also. There are 7 pots in thi...
by avandalen
May 15 2011 3:02am
Forum: E-Bike Technical
Topic: Calculation of front fork stress due to hub motor
Replies: 28
Views: 6008

Re: Calculation of front fork stress due to hub motor

(...) With a hubmotor, there is rotational force between the motor and the fork at the axle. Even if you have two very stout torque arms, the motor is still trying very hard to twist the fork. What do you think of this argument? It is clear that a hub motor generates a torque at the front fork. Dur...
by avandalen
May 14 2011 5:33am
Forum: E-Bike Technical
Topic: Calculation of front fork stress due to hub motor
Replies: 28
Views: 6008

Re: Calculation of front fork stress due to hub motor

I have heard many discussions where everyone has said that this is a really bad idea. A front fork breakage will send you flying over the handlebars, and that happens on aluminum and steel forks. Have you taken that into consideration? I can't help you with the calculations but i wanted to pitch in...
by avandalen
May 11 2011 3:57pm
Forum: E-Bike Technical
Topic: Calculation of front fork stress due to hub motor
Replies: 28
Views: 6008

Calculation of front fork stress due to hub motor

My bicycle has a carbon front fork, at which I will mount a hub motor. At first sight, a carbon front fork appears too weak to handle the forces of a hub motor. I wanted to solve this problem mathematically. I have done calculations which show that it is in principle safe to mount a hub motor in eve...
by avandalen
May 11 2011 3:36am
Forum: E-Bike Technical
Topic: Dropout Failure Experiments, and a call for Fork Donations
Replies: 184
Views: 45165

Is a carbon fork is strong enough for a hub motor?

See here for a new topic about the calculation of front fork stress due to hub motor
http://endless-sphere.com/forums/viewto ... 33#p403233
by avandalen
Apr 18 2011 4:15am
Forum: Battery Technology
Topic: Portable lightweight 360W LiFePO4 battery charger
Replies: 27
Views: 5684

Re: Portable lightweight 360W LiFePO4 battery charger

Very nice work, excellent design goals. A couple of questions: 1. Will this charge work with North American 110V 60Hz AC; 2. Will the voltage be adjustable for SLA, LiFe, and LiPo chemistry? Cheers! Hi The AC Input Voltage is 90Volts~132Volts or 200Volts~264Volts. Order the E400 charger with the ri...
by avandalen
Apr 17 2011 11:04am
Forum: E-Bike Technical
Topic: pre-charge resistor on charger?
Replies: 14
Views: 1099

Re: pre-charge resistor on charger?

I have made a lightweight battery charger with a built in anti spark circuit, maybe you can use this?
http://www.avdweb.nl/solar-bike/electro ... -800g.html
Albert
by avandalen
Apr 10 2011 5:09pm
Forum: Battery Technology
Topic: Portable lightweight 360W LiFePO4 battery charger
Replies: 27
Views: 5684

Portable lightweight 360W LiFePO4 battery charger

Because I want to fast recharge the LiFePO batteries during a trip, I need a lightweight mobile charger. Special lightweight battery chargers for ebikes don't exist. So I made one myself. I used the battery charger E-400 from BMSbattery in China. I have done modifications to the housing and the elec...