Cansai 36v charger suggestions?

Oops, be careful. My first look at the board was hasty -- and I was not wearing my glasses. But there is a fine trace from the one pad that appears to be part of a control circuit. And I confess that I gave it that careful look only after removing the jumper and soldering in the diode. Putting the diode in the obvious place didn't work. Oops.

But here's what did work. I put the jumper back in place just like original, but removed the red power lead and put the diode in series at that point. That is equivalent to the circuit I'd been using with the clip leads. Only now it's all contained within the box. It's charging away as we speak at 1.987 amps constant current. Just got back from a ride.

But having said all that, thinking that Mr. Wakataka's solution makes good sense -- to put it in with the battery case. If nothing else, it might prevent someone from blowing up their audio player trying to plug into the RCA connector on the battery pack!

Wish I could figure out how to post a picture...

Hey! Did it.

Speeking of Cansi Chargers. I received by WE BD36 from Bernson a little over two months ago. I think it was from the last batch of hubs imported. Anyway, my kit had a Cansi CS3606SR charger. Looks the same as a 3604 but it's output is 3amps. My question is, IS THREE (3) AMPS A BIT MORE THAN SHOULD BE FED TO A WE36V BATTERY PACK WHEN CHARGING? Seems that you all received a 2 amp charger. I'm wondering if what we get is what's within easy reach when they make up a WE pack for shippment? I'm having a great time with this hub and have had no problems with it. Did fall off my bike kinda hard and at 76 I found that I don't bounce as well as I once did. I,m learning to be real careful. HA. Russ

Shucks! I already cut the jumper. Well I can just solder it back together again. Samspeed, can I just splice the diode into the red power line inside the case instead of soldering one end to the circuit board? I only suggest this in order to keep from removing the board from the case? Thanks for all the information. Tony

Wait, that can't be right. On first exam it looked like Samspeed removed the red power line and soldered the diode to it's (red line) original board location. After looking at his photo (and mine above) again it appears that he removed the red power line from it's original location and connected it to a diode that was soldered to the board at the 'pointy' end of the diode symbol. Is that right Sam?

Hi. Two things first is that it probly don't matter anymore. Wilderness has delivered to me a nice new Soneil charger (3605s). My old Cansai is gone already, back to wherever it came.

Three Cheers for Wilderness Energy! They came through with their promises.

But the other thing. Yeah, tdetevis, you got it right. And it worked for me. The diode could go anywhere in the line. Even in the battery back. It's just to prevent current from flowing the wrong direction.

Final note -- My vendor told me to contact Wilderness directly for warranty service. That's what I did and they were courteous and for me, this problem is solved. I only gotta couple hundred miles on this bl36 so I gotta get busy working on that. You know, wind in your hair and bugs in your teeth....

Well I'm not cheering for WE at the moment. After about 7 weeks waiting, they send me a Cansai charger with the same symptoms as the defective one I'm trying to return! Only this time they included a sheet of instructions telling me to ignore the instructions on the charger and plug it in first before the plugging in the battery and then unplug it when the light starts blinking, etc. Everything we've figured out on our own here! Heck, it might even be SamSpeeds old chager that they sent me! No, wait. Sam had fixed his by installing a diode so I would be better off with his old one than this new one! They sent a return shipping label but no instructions about returning the old charger. Just a label lying loose in the bottom of the box. So it looks like WE is trying to fob off these defective chargers on customers now. I guess I'll just send the new one back to them because my old one seems to be working now that I've installed a diode in it.

Dear Friends,

I have read your problems about the Cansai 36V, 2 Amps charger. I've purchased a BL-36 kit and mounted on my bike a few months ago. My Cansai charger broken down in just the second time that I've used it. After being sure about its operation in the first charging trial, I trusted in the charger and left in ON for 24 hours when I was not at home! When I came back it was broken down, no LED lighting. So I opened it up and saw that the fuse was blown, current sense resistor (0.33Ohm) was burned out, and the MOSFET was short circuited. Also the turn-on driving resistor (SMD resistor I guess it was 51 Ohms) was burned out. I think I should see my self lucky that the fuse worked and I did not burn down my home :@

I was unlucky in a way that I did not have an international guarantee because I live in Turkey. On the other hand, I was lucky that I am an electrical & electronics engineer :)

The problem seemed to be about the MOSFET. It, becoming short-circuit due to a reason, all the other mentioned components were burned out before the fuse blew out. But, why did the MOSFET broke down?

The answers is, my friends, found out after some investigation with a colleague of mine. It was due to the lack of use of an appropriate snubber diode for the MOSFET. The charger in our hands is an SMPS forward converter. And SMPS devices usually employ MOSFETs. Switching OFF of a semiconductor device results overvoltage spikes, especially if there is a series inductance with that device in the circuit. So, circuits damping the spikes, so called snubbers should be used.

Yeah, there exists an RCD snubber for the MOSFET in our chargers, as it should be, but the diode used is 1N4007. Please open your charger and verify this. 1N4007 is a rectifier diode rated at 1A and 1000V. However, its turn ON and turn OFF times, (recovery time shortly), are very large. (tens of microseconds) Such a diode can not function in a MOSFET snubber circuit. Because MOSFETs are very fast semiconductor devices. A fast or ultra-fast diode should be employed with recovery time shorter than 500nano seconds. Using 1N4007 means no snubber action in fact.

What I would like to suggest is that, everyone should change that 1N4007 with a fast diode such as BA159.

Otherwise your MOSFET may break down.
I have to point out something by the way:

We have 230Vac mains here, not 110Vac as you have. Therefore the voltage that your MOSFETs see is half of that mine sees. Therefore you MOSFETs may not break down so easily. Especially people having 230VAC should make this change, if any. Another thing is that, the peak value of 230Vac is 325Volts and the MOSFET sees the twice of this voltage during normal operation. The MOSFET used in the charger is 700V/6A. The voltage value is close to limits. A MOSFET with 900V rating should be used.

If you think of changing the MOSFET, please be informed that the old one is isolated. That means, when you touch the heatsink you do not get electrocuted. You must buy and use a isolated 900V/6A mosfet or you should isolate the MOSFET from the heatsink with pad and an isolated screw. I do not want anyone to get electrocuted because of me saying you to change the MOSFET, so please be careful.

I do not have a heating problem here because since the voltage is twice of yours, the current is halved in the MOSFET. The funny heatsink works well for me. However it may not be enough when the current is 2 times as in U.S. You may need to change the heatsink also.

So, as you see, there are too many problems to this charger. The charger is made in China, no matter it is seen as sold by a Canada company. And some of the Chinese products as you may well know are really design disasters. They use wrong components, or do not the needed component at all. They do not use a reverse current protection diode at all, as dear SAM found out. This is just to reduce their cost and due to their lack of honest professionalism.

Not all Chinese products are like these, but I really get distressed when I use a Chinese product.

Best Regards from Turkey,

I hope I could help and inform you.
Hoping to hear from any of you about your experiences with you charger and BL-36 kit also.