PowerPac Electric Bike Limp Mode Fault

Hi, I have been given my dads bike to look at, He bought it brand new from some german company on ebay a few years ago and the first time he went to use it the wire going to the front head lamp melted and shorted out and now the bike will only go at a very low speed. I have removed the control unit to check for damaged components and cant see anything viably damaged, Would anyone know how i'd go about repairing this?

You start by charging the battery. After it's charged, you measure the voltage at the bottom with a voltmeter. it should be about 41v to 42V.

 

If that's OK, you connect everything and switch on. Then you check the voltage between the red and black on the throttle or PAS connector by stuffing your probes up the back of the connector while connected, it should be 4v to 5v.

 

Please post those two results here, then we can guide you further. I've never heard of a limp mode, but some bikes will only go 6km/hr with the throttle. Some will go faster if you pedal. Did you try pedalling, and is the pedal sensor connected?

battery hasnt been charged since it went into storage about 3 years ago but still reads 39.84v, voltage on throttle connection is 5.21v...

You need to charge the battery and report the voltage.

41.6v fully charged

still 5.21v on the throttle switch

 

;-)

Your battery is OK and your controller is powered up correctly.

 

Now you have to check the throttle signal. Measure between the black and the signal wire while it's connected and powered up. It should change from about 1.2v to 3.8v as you open the throttle.

 

I just noticed that you mentioned German Ebay. They only have 6km/h throttles in Germany. Our type of throttles are not allowed. You can only get speed above that with the pedal sensor, so forget the throttle and concentrate on getting the pedal sensor working.

 

There may be two single wires from the controller that are joined in a loop that fixes the 6 km/h. Does the controller have anything like that? If not, you'll probably need a new controller to get the speed from the throttle.

Just asked my dad and he said he doesn't think there was a pedal sensor as it did go faster the first time he used it, also when he pedals it doesn't change the speed,

 

0.839v when throttle is off and 4.5v with throttle in full position

 

There is 2 blue wires coming from the controller both joined in a loop, when i disconnect these it does increase the speed but not by very much, i also see a little adjuster screw in the same loop,

I'm pretty sure that the adjuster screw adjusts the speed limit with the loop connected. There's no limit with the loop disconnected.

 

Look behind the chainwheel/s. Is there a black disc with a ring of shiny magnets in it?

Yes mate, I see the black disc with the magnets, I take it it has a pedal sensor then.. ;-) Also is it ok to leave the blue loop disconnected to get a bit more speed from the bike or should i keep it as stock so as not to damage anything,

Leave the blue loop disconnected.

 

Now you need to check the pedal sensor. It should have 5v on the red and black wires. Then you check between the black and signal wire. It should pulse 5v on/off as each magnet passes when you rotate the crank slowly.

Ok on the pedal sensor wire the black and red measure 5.27v but the black and green signal wire measures a constant 2.68v even when i'm turning the pedals.

Hmmm! Doesn't sound good. Is the connector one of those little black JST 2.5 SM 3-pin connectors?

Yes it is, Would it work if i connected the green to the red then that way it would have a constant 5v or does it need to pulse on and off??

No it counts the pulses to know how fast you're pedalling. You'll have to get a new one. If your search Ebay for "PAS sensor Pedelecs", there's one for about £12, which is ridiculously expensive considering that you could get the same one for 60 pence from China.

Here is a few pics of the PAS sensor

 

http://tinypic.com/r/24uwz87/8

http://tinypic.com/r/2sbok75/8

http://tinypic.com/r/2jctqur/8

http://tinypic.com/r/mjsifk/8

http://tinypic.com/r/fxa8h/8

http://tinypic.com/r/fxqr6g/8

http://tinypic.com/r/xc6592/8

 

5 magnets wheel, Would anyone know by looking which one this is I need,

Was in halfords earlier and got a crank extractor and bottom bracket tool though i don't think it is fitted with a shimano BB, I asked the guy in halfords for one but he didn't know much about bikes so couldn't help, told me to call back tomorrow.. :-o

Got it all off. ;-)

 

http://tinypic.com/r/16ifm08/8

This is the Halfords BB that fits to most bikes.

 

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_158268_langId_-1_categoryId_210159

 

Your one looks quite long. You need to measure the length of the shell on your frame. If it's 68mm, you can buy the Halfords one.

 

I've not seen a PAS like yours before. The magnet disk is standard, but the sensor might not be. Normal sensors are just a hall sensor that switches on and off as the magnet passes; however, there are some sensors that have electronics that convert the pulsing into an analogue signal to the controller like a throttle signal.

 

I think we need to sort out the BB first, and then try a standard Chinese PAS to see if it works. Send me your address, and I'll lend you one to try.

Found some specs:

 

http://www.greencarsite.co.uk/4sale/00124-mountain-bike.htm

 

or this look a like:

 

http://www.amazon.co.uk/Pro-Rider-Voyager-Electric-Mountain/dp/B00AE6GWNO/ref=aag_m_pw_dp?ie=UTF8&m=ASEO66V93LWQW

Edited March 31, 201412 yr by shemozzle999

Thanks d8veh, I got 90mm from on side of the bb housing to the other, Ive included a pic, Also 2 pics of the inside of the pas sensor if it helps, I removed and tested all 3 caps from it and they're ok, Think the component IC2 looks to be damaged,

 

http://tinypic.com/r/qstf8i/8

http://tinypic.com/r/xlba1c/8

http://tinypic.com/r/2csc3g9/8

 

And thanks for the specs shemozzle999... ;-)

Has the magnet disc been rubbing on the PAS module and worn through to IC2?

 

See if you can see any markings on IC2, 3 pin device, which would help identify it.

I had a feeling that yours would be like that. The 8 leg component could be a microprocessor that translates the hall signal to an analogue one or anything else. IC2 is the actual hall sensor. There's some info here to explain how it works:

http://www.bristolwatch.com/hall_effect/

 

The main point is that you should have 5v between pins 1 and 2, and pin 3 should go on and off when you bring a N and S pole magnet to it, Can you test that while it's powered up?

 

If it gets the 5v but doesn't switch, you can replace just the hall sensor, which costs pence. I can give you the spec later. If the hall sensor is OK, but the rest doesn't work, the easiest thing is to get a new KU65 controller plus throttle and PAS from BMSbattery, which should cost about £35. Then you'll have a conventional system that everybody understands.

 

I don't think you can get a cartridge BB in 90mm, so you should take your BB splined tool back to Halfords and get a couple of replacement caged ball races while you're there.

Magnet disc has been rubbing the PAS sensor but has not yet worn through, IC2 appears to slightly damaged looking, Here's a close up,

 

http://tinypic.com/r/k9f91f/8

It looks like it has been blown - replacement from here:

 

http://uk.mouser.com/ProductDetail/Diodes-Incorporated/AH173-PL-A-A/?qs=EJYhozv%252bYpyUN8vu3DMslQ==

You need to do the measurements above. it could be a different voltage to 5V too.

Enter Quantity: (Minimum: 2550) << I only need 1... :-)

Also I'm no expert but the numbers on my ic2 is 173 621v which is prety close to the 621-AH173-PL-A-A shemozzle999 posted and it says Operating Supply Voltage 3.3v or 5v or 9v,

 

I found this AH175-PL-A-B on Ebay

 

http://www.ebay.co.uk/itm/HALL-SENSOR-LATCH-GRADE-B-3SIP-Part-AH175-PL-A-B-/271226750516?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item3f265fc634

 

Does this look like the same component??