Big regrets buying the 1500w Voilamart rear hub conversion kit

Fort Ord

Fort Ord

Member
My situation: last year, August, I bought a Voilamart 1500 watt rear hub conversion kit. I have two 48 - 52 V batteries on a bike pannier rack, long story behind that one, suffice it to say it got me to/from on a 25 mile commute. In December, weird things started: the throttle battery power indicator would drain from full charge to empty in less than five miles, at which point I'd stop, connect the 2nd battery and go another 5. When I'd get home, the batteries would fully recharge in 2 hours. This alone tells me the LED battery indicator on the throttle is inaccurate. So: I have tried new (three of the Voilamart ) controllers, 3 new throttles, and nothing works now. When the controller connected to the battery the bike won't start . Is there a way you'd recommend where I could take the controller off the bike and test it with a multimeter? The batteries test fully charged, and I am getting to the point where I throw the Voilamart components out and buy new conversion kit. Your input here would be greatly appreciated!
 
tomjasz said:
cheap and inaccurate voltage readings.

Tested with a multimeter?
Click to expand...
Hi, yah. Tested the batteries with a multimeter, 54V and 52.5V respectively. I should frame my question differently: How can I test the new voilamart controller( #3 thus far )presently assigned to the bike - if I try to test while the controller is attached to the power source, I cannot get any kind of reading because the new throttle won't light up and I get no response when I turn throttle-on button on.
 
If you've got 2 batteries that worked before, and 2 controllers that behaved the same, I'd suspect something wrong with the motor. Get an amp clamp meter, put it around the phase wires one at a time, and ride. Flat level ground, normal sized tires, 5 mph, the motor should be drawing 2 to 5 amps on each phase. 10 or more, you have a motor problem. Could be shorted turn. Hint, meters with a pointer are easier to read from a distance than digital numbers. https://www.newark.com/multicomp-pro/mp760606/clamp-multimeter-4000-count-400a/dp/13AJ0604
You can test the batteries on the back step with a DVM a 10 ohm >400 w resistor and some aliigator clip leads. Charge the batteries, put the DVM on volts across the resistor, attach the load. Battery should put out ~5 amps for however many hours that divides into the watthours. 53.6 v / 10 ohms is 5.36 amps. More than an hour you don't have a bad weld in the battery problem. If resistor doesn't stay warm you do have a problem. If you have a 10 ADC scale, you can put the meter in series with the current and measure the amps directly.
My 1000 W DD hub motor was fine. Just ate beaucoup electricity climbing hills slowly, which is what I do a lot to and from my summer camp. Dragged unpowered like being in two higher sprockets than I was. I ride unpowered a lot too, for my health. I don't regret the $189 I paid for it, a cheap throw away product.
 
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So, both batteries after a full charge are less than expected. 48V should be 54.6, 52V should be 58.8V.
But that wont prevent running.

I’m curious u, have you purchased all three new controllers and throttles?

Fort Ord said:
the throttle battery power indicator would drain from full charge to empty in less than five miles
Click to expand...
But we have no actual battery voltages when this happens?
Fort Ord said:
This alone tells me the LED battery indicator on the throttle is inaccurate.
Click to expand...
But no actual voltage reading?
 
tomjasz said:
So, both batteries after a full charge are less than expected. 48V should be 54.6, 52V should be 58.8V.
But that wont prevent running.

I’m curious u, have you purchased all three new controllers and throttles?


But we have no actual battery voltages when this happens?

But no actual voltage reading?
Click to expand...
Hi Tom,
1. Yes, I purchased three controllers, four, 6-pin throttles actually, 2. (red-faced) no, I didn't get actual voltage readings at the time. It's looking like I either replace the controller, throttle and display with KT components, or just buy a new, different conversion kit. The bike at present is unridable except by human propulsion. hence my question about how can I test the controller to see if it is the problem?
 
Unfortunately I'm weak as hub motor failures go. I've never had a failure. 99% of my trouble shooting skills are with Bafang mis drives.

BUT if it were my issue I'd Google my way to an answer.
I just searched this long phrase. Not an ideal search ebike hub motor how can I test the controller to see if it is the problem?

That found this too. I bought the pictured test tool, but haven't ever used it.

Hopefully, @harryS will chime in. He's likely the best budget kit sorter here. I'd poke him if I were you. I learn something form nearly every one of his posts.
 
Does putting the original controller on the bike make it run short distances? I'd try that.
New controllers come with two different types of brake hookup (NC or NO), pas pickup required or not, throttle required or not. Any of those wrong it will just sit there. With a display you can get an error code but nobody has a list of error codes to meaning. On mine I've found err02 means a phase wire is doconnected, and err07 means the pas pickup is not hooked up. You can change the configuration with the display & up down buttons on the level controller, but there are no instructions on this cheap ****. Parameter number meaning probably varies from month to month. Support & documentation are not part of the low price ebike parts market.
If the bike does run with original parts, I'd take the original controller apart to see if the main caps are leaky. Not physically, electrically. I'm still using a 2018 ebikeling controller because I changed the electrolytic caps from garbage to 5000 hour service life 105C rated ones from newark. I also installed a aluminum bar with heat sink compound from internal heat bar to pretty external ribbed aluminum case, which was too expensive for ebikeling's supplier to bother with. The advantage of the 2018 controller, it does match the display, original brake handles, & original pas pickup. Nothing else does.
If the caps don't leak, and it does run 5 miles, then I'd suspect the motor. batteryclearancehouse.com has used 36v motors in a 26" wheel for $45 and bare motors for $24. Mine works. I protected the 36 v motor from a 48 v battery by putting series 0.5 ohm 130 W resistors in each phase. Tested for 2 miles but not more, winter hit & I put the battery away. 0.5 ohm 20 watt resistors did not work, one burned out in the middle of a steep hill. Warning those 11 pin juli connector to 6 pin rectangular block adapter harnesses are hard to get. The first one I bought was the wrong sex. I found rectangular block connectors with bare pins on ebay & had the juli connector cut off & replaced before the adapter harness got here from *****. Phase wires are now .157" bullet crimp terminals from dorman (oreilly's).
 
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indianajo said:
Does putting the original controller on the bike make it run short distances? I'd try that.
New controllers come with two different types of brake hookup, pas pickup required or not, throttle required or not. Any of those wrong it will just sit there. With a display you can get an error code but nobody has a list of error codes to meaning. On mine I've found err02 means a phase wire is doconnected, and err07 means the pas pickup is not hooked up. You can change the configuration with the display & up down buttons on the level controller, but there are no instructions on this cheap ****. Parameter number meaning probably varies from month to month. Support & documentation are not part of the low price ebike parts market.
If the bike does run with original parts, I'd take the controller apart to see if the main caps are leaky. Not physically, electrically. I'm still using a 2017 ebikeling controller because I changed the electrolytic caps from garbage to 5000 hour service life rated ones from newark. I also installed a aluminum bar with heat sink compound from internal heat bar to pretty external ribbed aluminum case, which was too expensive for ebikeling's supplier to bother with. The advantage of the 2017 controller, it does match the display, original brake handles, & original pas pickup. Nothing else does.
If the caps don't leak, and it does run 5 miles, then I'd suspect the motor. batteryclearancehouse.com has used 36v motors in a 26" wheel for $45 and bare motors for $24. Mine works. I protected the 36 v motor from a 48 v battery by putting series 0.5 ohm 130 W resistors in each phase. Tested for 2 miles but not more, winter hit & I put the battery away. 0.5 20 watt resistors did not work, one burned out in the middle of a steep hill.
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You're definitely not the average kit builder. I'm afraid this is over most builders' heads and skill sets. Mine for sure.
 
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Hi, thanks all for your excellent tips and advice. I've ordered the tester (thanks Tom) and I'll go from there. Much obliged, rd
 
Fort Ord said:
Hi, thanks all for your excellent tips and advice. I've ordered the tester (thanks Tom) and I'll go from there. Much obliged, rd
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Over my 8 years of eBike kits, I've become a better "Googler". A well-thought-out search string with proper nomenclature can usually find answers for me faster than forum responses. YMMV

I'm sorry I can't be more helpful.
 
tomjasz said:
Over my 8 years of eBike kits, I've become a better "Googler". A well-thought-out search string with proper nomenclature can usually find answers for me faster than forum responses. YMMV

I'm sorry I can't be more helpful.
Click to expand...
Faster yes, but experience from the Forum is more helpful.
 
The way to tell if your controller main caps are garbage, unplug it from the battery. If in an hour you plug it back in again and there is a big spark, the caps are ****. If you wait 12 hours and plug it in with only a tiny spark, the controller has good main caps.
 
If you have three controllers, and the motor doesn't work, then it's a wiring problem or the motor is dead.

The quick way to test is to find someone with an ebike and plug the motor into the other bike, and vice versa. Should be a DIY club or network for that, but there aint.

The original problem sounds like unbalanced batteries. They are going dead, and it only takes about 4AH to recharge them. Typical of inexpensive batteries to do that, They don't have consistent cell quality.

The motor tester can tell you if the Hall Sensors are working. If you hook it up to a properly wired controller, you should see this pattern when the throttle is opened. It only "spins" once, but you can make it loop by blipping the throttle.

 
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