Jump to content
elementary

NEW Banggood 264wh TG-F3...handlebars & shunting?

Recommended Posts

The TG-F3 264wh seems to be a great purchase and I am please with it

Because I am 70 years old, you might expect me to be using training wheels, and you are correct.  

They got me up and riding in 15 minutes and I have been able to waddling riding around a parking lot using them

Without a doubt, I think the training wheels will be are necessary for several weeks as they allow me to lean on them for backing, turning and catching my balance.

My concern is shunting, it has not happen to me, but for safety reason I would like to know which leads to shunt ...  yikes falling with 70 year old bones could be a problem !!!

Based on postings, should I assume it is the right three and I shorting the middle pin to the right pin of each is the correct procedure?

Thanks

TG-F3264wh.jpg

Edited by elementary
Added to title

Share this post


Link to post
Share on other sites

I have the same unicycle and the same question. If anyone could confirm which transistors shoud be shunted it would be great.

Share this post


Link to post
Share on other sites

I thought about solder, but the terminals are too small to heat so I order Silver Electrical Epoxy which should work....  I checked with a meter and it looks like the right two on the three MOSFETS but have not done it yet

Here is the latest mods to the excellent TG-F3 264w from Banggood

 

IMG_20150823_093005574.jpg

IMG_20150823_093018954.jpg

Share this post


Link to post
Share on other sites

I thought about solder, but the terminals are too small to heat so I order Silver Electrical Epoxy which should work....  I checked with a meter and it looks like the right two on the three MOSFETS but have not done it yet

 

I would be very careful about using conductive epoxy or similar. The currents flowing thru those wires are pretty big. The conductive inks/epoxies tend to have pretty high resistance, compared to a wire. Not only you will have a small voltage drop (probably too small to notice), but you will have a resistor in series on a high current load. Let's say you have a 15A spike (not unlikely in a EUC like yours). The power dissipated by a resistor is p=I^2 * R. If your connection is 0.5 ohm (not unlikely with a conductive ink, given that there is the solder joint/epoxy interface), that means that the conductive ink has to dissipate 112.5W. Most of the heat generated as a result will be in the part with the highest resistivity, usually the interface between the solder joint and the epoxy. That will cause thermal stress and debonding over time (helped by the vibrations).

I know that silver epoxy is supposed to have a 0.03 ohm/cm resistivity, but unless you have a milliohmeter and can measure the actual resistance of the resulting joint, I would assume that the less than perfect contact between solder joint and epoxy will give you worse real life performance than the theoretical specs from the manufacturer

A solder joint, while maybe harder to make, is much safer. Also, given that you have a "generic EUC" with unknown batteries, I would caution about shunting without also monitoring the cells for overcurrent (the mosfets protect both against over-discharge and over-current... the over-discharge can be handled more gracefully by the control board, but the over current might not). I would suggest you read my posts in the shunting thread, just to at least be aware of that theoretical possibility (and a potential workaround I posted today)

Share this post


Link to post
Share on other sites

Thanks, I decided not to shunt... I think my Banggood TG-F3 264W motor is almost dead as only goes slow...

yep... All voltages look good and nothing is burned up.

But I weigh 230 and although it is rated for 264 pounds I don't believe it can handle it.

 Now I need to figure out how to trash a DEFECTIVE two week old EUC.

$$$ down the drain

 

Share this post


Link to post
Share on other sites

Ouch... did you measure the voltages good under load, though? Chinese specs are always optimistic, so a EUC rated for 264 is actually probably good only for 150 pounds or so, so you might have overloaded the cells (an EUC motor has to work extra hard to keep the balance, the power spikes can be pretty significant, especially considering that the center of gravity of the weight is well above the motor).

A battery pack with a damaged battery will measure 100% when unloaded, but you will see one of the batteries drop fast when loaded (and hard to measure if you measure the pack: a fully charged 16 battery pack with a battery dropping to half the voltage under load, will show 65V instead of 67V, and that can be interpreted as normal voltage sag, when in reality one battery is completely dead at 2.2V, and the pack is providing only half or less of the rated A) . You could create a dummy load capable of drawing enough A to load the pack, then measure the individual cells voltage (can easily be done with a voltmeter piercing thru the heat shrink). You could use 5 automotive lamps (the powerful ones, high beams) in series. If you use 55W high beam lamps (5 in series, so none burns due to over-voltage), you will get ~4.2A sustained across the pack, and that would load each cell close to 2C, when the voltage drop will be very obvious if a battery is even marginally damaged.

If you determine the pack to be faulty (and not the motor or controller board), you could resell your EUC for a good price (disclosing the problem), and the new owner will only have to replace one battery and have a good children unicycle)... chances are, the battery is the one that dies well before the motor or controller

Edited by robca

Share this post


Link to post
Share on other sites

Hello Elementary. I am 76, you'r rather young ! I bought a TG F3 too, 3 months ago. I kept the training wheels a long time, a too long time I estimate now, I should have removed them earlier instead of loosing time. I have shunted my wheel after a sudden stop at  12 km/h and a forward fall, a bit shaked, but not really wounded. I shunted two of the 3 similar transistors to avoid that ! I also removed the beeper which is no use (just annoying), the pedals lift up far (at 13 km/h) from the maximum speed announced (18 km/h), that you can never reach anyway. I think you MUST shunt it, especially if you run with that bar beetween your legs.

I complained to Banggood before and they sent me a new wheel card (not BMS), on which the cooler is no more just a massive bar but has winglets cut in it, probably much more cooling efficient.

I have bought also a "Charge Doctor" from a french wheeler. It indicates the load you take, and from zéro, mine took 285 Wh, better than the 264 that Banggood announces. Probably, if you had such a device, you could judge and proove if your battery is normal or not.

Edited by Maxime
forgot concerned guy

Share this post


Link to post
Share on other sites
Guest

[...] I have shunted my wheel after a sudden stop at  12 km/h and a forward fall, a bit shaked, but not really wounded. I shunted two of the 3 similar transistors to avoid that ! [...]

Hi Maxime, I am curious in what situation and why your TG-F3 stopped working. I have the same wheel (loove it) and go out for one and a half and two hour rides and definetely want to avoid such an accident. 

Share this post


Link to post
Share on other sites

Hello ScooterB. Wheel full, I rolled around 25 mn in roads slopy but not much (5 % ?), up and down. Then, I ran on an horizontal way for pedestrians beetween houses and had the bip several isolted times. I continued, but some time, I had the bip repeatedly so I braked more suddenly (not very strong, but I braked). The wheel stopped, but I continued ! I rolled forward on my shoulder, not really wounded, but mentally shocked.

I don't know if the repeated bip was due to excess speed or some failure (overheat ?).

I adressed to Banggood, read(ed) some forums and decided to shunt as indicated.

By the way, I installed the new card Banggood sent me and it works, and I shunted after. I have had no stop problem since that time.

Share this post


Link to post
Share on other sites

Hello ScooterB. Wheel full, I rolled around 25 mn in roads slopy but not much (5 % ?), up and down. Then, I ran on an horizontal way for pedestrians beetween houses and had the bip several isolted times. I continued, but some time, I had the bip repeatedly so I braked more suddenly (not very strong, but I braked). The wheel stopped, but I continued ! I rolled forward on my shoulder, not really wounded, but mentally shocked.

I don't know if the repeated bip was due to excess speed or some failure (overheat ?).

I adressed to Banggood, read(ed) some forums and decided to shunt as indicated.

By the way, I installed the new card Banggood sent me and it works, and I shunted after. I have had no stop problem since that time.

Did shunting your EUC fix the issue before you replaced the mainboard?

Edited by Tom

Share this post


Link to post
Share on other sites

I explained too quick : first I changed the card, then I shunted. My old card is as it was. I keep it in case a problem occurs.

Share this post


Link to post
Share on other sites

Hello, is there any tutorial/walkthrough on how to shunt the Tg F3? I too would NOT want to faceplant while riding it.. Any help is greatly appreciated :]

Share this post


Link to post
Share on other sites

Congratulations to both!  :D

@Maxime - very brave, and impressive!

@elementary - I think that is a pole for land boating isn't it?  Forgive, I don't know what it's called.  A tip - you won't know it in the beginning but the training wheels hamper learning to ride the single wheel - it should only be used for 15 mins.  But if the goal is something else then that is a different story.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...