2 Controllers Toasted in 2 Minutes?

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David LaFerney   10 mW

10 mW
Posts: 33
Joined: Aug 16 2016 7:31pm
Location: Cookeville, TN - Southeastern United States

2 Controllers Toasted in 2 Minutes?

Post by David LaFerney » Sep 17 2016 3:44pm

I just finished assembling 2 ebay* kits

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 5136905012

The homebuilt battery packs*** are 48v 20 amp and Should be about right for a 48V 1000W kit - I would think.

Anyway, both bikes fired up - all systems go according to the SW900 LCD and seemed to run quite nicely for a minute or so - then stopped. One gave error code 10 - "Communication Receiving problem." The other gave error code 6 - "Battery is undervoltage." Which is absolutely not correct - the battery was at 50 volts. I checked connections, disconnected and reconnected batteries - but still the same. The LCDs work but that is all - they still display the same error codes.

After sleeping on it, my unqualified guess is that the controllers are toast. I'm a big guy and the peak current may have just been too much for them. I reached out to the vendor - who in all fairness did respond right away with a form letter, and instructions to email a video so that they can try to help me. I'm guessing they need a video because their English is not much better than my Mandarin.

In any event, I'm willing to buy new controllers instead of installing OEM replacements if they're that lame anyway. Does anyone know if the Lyen controllers are still available? They seem to be highly regarded. I know I will lose the LCD bells and whistles, but I'm not fretting about that all that much. I want something that will be reliable even if it's just a motor, controller, and a throttle.

It would be awesome if it's actually something much simpler, but I'm not optimistic.

*I know (now) buying kits off of ebay was a mistake, but I started this before I even heard of endless sphere, and I read on a blog that it would be OK. I'm shocked to find that blogs publish things that may not be accurate. Live and learn.

**The batteries are 13s4p built out of Panasonic NCR18650 3400 MaH - according to the spec sheet delivers 4.875 amps continuous - so about 20 amps for the whole pack - about 1000 watts more or less.

***Since I have built what I believe are pretty decent batteries, If I get good controllers I'm only a hub motor away from making some pretty decent ebay kit bikes.
Last edited by David LaFerney on Sep 18 2016 10:47pm, edited 1 time in total.

SlowCo   100 kW

100 kW
Posts: 1192
Joined: Jan 05 2015 5:43pm
Location: The Netherlands

Re: 2 Controllers Toasted in 2 Minutes?

Post by SlowCo » Sep 17 2016 4:08pm

I'm no expert but as far as I know 48V 1000W ebay kits will have a controller that can have a peak battery current draw of 30A to 40A. And with 13s of nominal 3.6V cells you built a 46,8V battery. When trying to pull 30-40A from your battery the voltage sag will probably be so much that it will dive under the "low voltage cut-off" of the controller. So if i were you I'd build a 14s battery and more than 4p. Your controllers are probably fine.

David LaFerney   10 mW

10 mW
Posts: 33
Joined: Aug 16 2016 7:31pm
Location: Cookeville, TN - Southeastern United States

Re: 2 Controllers Toasted in 2 Minutes?

Post by David LaFerney » Sep 17 2016 5:38pm

Slow-Co,

You weren't wrong. The problem was low voltage, but not for the reason you guessed - but your reply put me on the right track to figure it out. The LCD interface has lots of configurable things, and despite being sold as "36-48 volt" and the controller actually being labeled as 48v - the (hidden) software setting was for a 60-volt battery. Changing that to 48 sorted it all out. This thing came with almost no useful instructions at all, but I found this PDF guide for the LCD which made it possible for me to do. So thanks.

http://www.boatstogo.com/images/Saturn- ... -SW900.pdf

I'm really glad I asked.

SlowCo   100 kW

100 kW
Posts: 1192
Joined: Jan 05 2015 5:43pm
Location: The Netherlands

Re: 2 Controllers Toasted in 2 Minutes?

Post by SlowCo » Sep 18 2016 3:08pm

That's good news!
Enjoy the ride.

David LaFerney   10 mW

10 mW
Posts: 33
Joined: Aug 16 2016 7:31pm
Location: Cookeville, TN - Southeastern United States

Re: 2 Controllers Toasted in 2 Minutes?

Post by David LaFerney » Sep 18 2016 10:46pm

We rode them about 10 miles today with no problems.

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