Hi Julian - I have a Bantam eStation 902 charger (two actually because I blew up the first one) - it is built in exactly the same manner, and the bar pressing against the MOSFETs was bent on that one too. I replaced the MOSFETs on the broken one, but it still needs me to replace some op-amps too - I've yet to upgrade my electronics tooling to handle doing surface mount packages, so it's been sitting on a shelf for nearly 4 years now waiting for me to finish the repair. Thanks for another interesting vid. Cheers!!
I wonder if that bar was also drawing some of the heat away from those devices, which it surely isn't doing any more with the addition of those rubber feet.
If you want to add a temp sensor, the receptacle looks the same as my imax b8+. With the thermal sensing, it has worked great detecting overheating Li-Ion batteries and halting the charge before it went critical. "TS-474002/11777 Temperature Sensor w/ Futaba plug" was what I got. It's got a curved magnetic side that's perfect for Li-Ion's. I'm still searching for how to reduce the LiPo maximum charge voltage because 4.2V is actually hastening death of the cells. 4.1V gives longer life. It could be accomplished through the secret calibration mode but that affect all the battery voltage readings.
Thanks for the partnumber. In my country I couldn't find it with that partnumber, bu I could with this one: Futaba SBS01T. It's also an 3-pin temperature sensor (White/Red/Black or vice versa). For anyone reading, all you need is a generic 3-pin sensor, 2 pins for supply, one for readout. My guess is it runs on 12V but I don't yet have a sensor, nor have I tested it.
Thank you for the inside look, especially on how to get the buttons out. My buttons are sort of malfunctioning...they work intermittently and I'd like to replace them. Any idea on how best to go about it? I find that if I apply extra-firm pressure to the buttons they work, but "regular" pressing doesn't really work.
Nice video Julian. Welcome to the wonderful world of HK. there's a reason this stuff is so cheap and you always stand a 50/50 chance of getting stuffed when you use them.
Destroyed a tact button pulling off the buttons that way, but lacking any other alternatives, you might as well plan on replacing all 4 buttons with a breakout board.
So you've made it better while voiding the warranty. :) I wonder if those rubber/plastic feet will hold their compliance or cold-flow over time and reduce the pressure they apply to the to-220 packages?
I just bought two of these off Hobbyking and would you believe, the bars are also bent on mine as well. They must churn these things out by the thousand and not care about thermal efficiency. I'll have to rip mine open to bend the bars back into shape at some point.
Hey there, thought I would open up my Accucell-6 as a comparison. Pretty similar construction although the mosfets are on the bottom, certainly close enough that you could call them siblings. But the thing I thought you might like to know is that there are no manufacturer name markings on the PCB of mine either, so that too is consistent at least & I'm pretty sure mine is genuine. I would say that your one simply passed through a Quality Controller who had a rather liberal interpretation of their own job title/description :)
The only hint i had that it may be authentic was the fact that the LCD can be detached thu a plug , usually for cheapness they wouldent do that and solder it directly to the board. You may want to monitor it using a alternative multi meter device to see if its safe during charge.
Julian Ilett hi, i was slightly worried when you put thee rubber feet on, i know from experience that the charger can get rather warm, and i am worried the rubber would melt and maybe cause a fire hazard... whats your thoughts on this?
Is there any reason you can't drill and tap mounting holes for each semi on the heatsink doing away with the bar totally? It would be a bit of work but would be a lot more robust both thermally and mechanically.
It occurs to me that and an angle extrusion rather than flat bar might have been a better idea for the MOSFET clamp - more resistant to bending. Turnigy's bodgery on the mechanicals is world-class on this one!
Marcus Jenkins I used this method a while back in my grid tie inverter. That did have a U-shaped bar (quite a shallow U) across all the MOSFETs and diodes. But it was susceptible to bending just the same.
Hi Julian. I'm new to your channel and loving it.. Going by the bodgery in your charger, have you thought about getting one of the knock-offs to see if they're really that bad?
The To220 package is cooled by heat transfer through the metal tab at the back. Sure, a small amount will also pass through to the front, but I reckon the improved thermal coupling between the component tabs and the heatsink extrusion, far outweighs the loss of the metal bar at the front.
i've had 2 imax B6 chargers so far and people are always debating in the comment section weather they are fake or not, it doesnt really matter. first off even the "fake" ones are still pieces of equipment that work, by "fake" it sounds like they mean its just carved out of a block of wood and doesnt do anything. also the "real" imax b6 chargers are made in china and are shitty just like the fake ones. if somebody really wants quality they need to build it themselves instead of paying 30$ on ebay.
Hmmm. Seen as they've likely had the case profile made, a small detail would have allowed the use of those snap-in clips to hold the devices on to the heatsink. Better performance and faster assembly too. I've seen u-section strip used with this screw arrangement, but also with a screw in between each device. Someone clearly doesn't have a clue. Maybe that's the same person saying that the failing units are fakes? Let's face it, not everyone will be running the unit at the limit of it's claimed spec. So their units will survive a little longer.
Julian Ilett Costs a lot more to produce as each device would require a screw, sil-pad (placed accurately on hole), top hat and testing of continuity to chassis.
Note to self The pinout of the Power Supply side is shown here: 5:10 Flip the board over, Mosfet side to self where the supply holes should be at the bottom right. Top hole is positive, bottom is negative.
Hi! I just recently bough IMAX B8+ from hobbyking and it has that same bending bar inside. Tought it would have had a little bit better quality than turnigy but it seems to be almost the same inside.
I like your videos a lot but rubber thingies there on the components, is this really a good idea? Those can prolly get pretty hot on that side too, also there's no way for that flat bar to keep them pressed against the radiator without bending. Even after your mod there is a slight bend to that bar. I'd get a piece of thick square/rectangular alum tube cut it to properly fit(kind of an u shape) and use that for support..., and lose the rubber thingies :) surely more work but it will be more rigid
Great vid Julian, although on seeing the heatsink, I kinda wanted someone to shout "YOU GOTTA BE SH*TT*N' ME!" in an Australian accent for some reason...
The charger will shut down before anything melts. There is a NTC-resistor on the heatsink that controls fan speed, and shuts down the unit if it gets too hot.
The mosfets still get quite hot when charging a 5A + charge rates on these chargers, so I also be concerned the rubber feet melting... they're not exactly meant for high temperature situations! That being said, i have a hobbyking 4 way charger, a genuine iMax B6 + plus several turnigy accucell 6s - none have failed yet. Worst thing that's happened is failing buttons that have needed cleaning.
Peter Feerick Julian Ilett I believe rubber melts between 150 C and 300 C depending on the rubber so well above what those MOSFETs should safely operate at. However, some plastics have a melting point of as low as 70 C which is a bit worrying. So as long as this is a good quality rubber, it should be OK.
The bar needs to be reverse curved, so that by the time there is enough screw force to straighten it out, it is applying uniform pressure across all the devices.
What's odd about the USB socket pads, is that only two of the pads appear to be connected up. I can only assume that these are Tx and Gnd, and that it's not really USB at all. It must be a serial data stream and require a FTDI-type USB/serial converter cable. I guess I could put my scope on the data pin and see if it's squirting out data bytes.
John Knutsson It looks to me like pin5 is grounded, and pin3 goes off to the microcontroller - no other pin is connected. I'm using this as a reference: forum.sparkfun.com/viewtopic.php?f=19&t=33227
Not to related to the video. But I'm looking for the cheapest way to go about setting up a battery backup. Doesn't need to be super reliable . I'm thinking about getting a couple 50 watt solar panels and a few of those cheap eBay charge controllers. With a 500 - 700 watt inverter. I'd probably only ever use 200 watts for more than 15 or 20 minutes . I just want it to have the capability of running my mini fridge if I have to use it for that. The hardest part is finding cheap batteries. I want it to have a battery bank with a decent capacity
Julian Ilett The USB is for a Temperature Probe I got one from china but someone in china wired it up the wrong way around I reversed the wires and it works before it was reading 70C in a 20c room lol I refer to the 3 pin terminal on the left.
the only possibly looking genuine IR mosfet in that pack is maybe the one next to the 5v reg, it has the usual half round ears cut into the tab, Most IR fets have a cut that from the top down goes in at a sharp angle and then curves back out, like a semicircular cut with a flattened top Getting genuine mosfets is hard, I even had some from an ebay seller who was getting them off one of the UK main component houses, but I Really Shouldn't name them..... Your 'spacer fet' looks genuine IR any views on rubber mat insulation/thermal performance over old mica insulating with thermal compounds ? I've never liked rubber, to me its an insulation....
I recently bought an IMAX was very unhappy with it as it was a FAKE and the voltages where off by about 700mv that might not seem a lot but when charging LION cells it can be dangerous, I complained to the Ebay seller and got a full refund, plus I pointed out to the seller that selling counterfeit goods is a crime in the UK and even distributing them is a crime, as a result I was not asked to return the item, so got money back and got to keep the IMAX.. I later bought a TURNIGY ACCUCELL 6 with my refunded money from Hobby King and it is much better, but never got a user manual or pretty box was bare cardboard :p
My trunigy 8150 charger goes off after couple of minutes.. does any one have any clue what to go check. the power adapter is fine and it works well with my other charger
I have a question not regarding to this charger: I got a couple of LEDs from a friend wich he doesnt need any more. They look similar to this: s1309.photobucket.com/user/99freezone/media/ebay%20%20pictures/FZ0340-03_zpsf27beb98.jpg.html Now how can I tell if they are 1W or 3W LEDs? (he can't tell either) I mean I could apply 700mA to one, an when it blows up, then its an 1W LED, but are there better ways to find out?
Seeing that, how much worse can it really get with a "fake" one? Since the board is totally unmarked, I think it's the typical "one product, hundred labels" item.
Julian Ilett Yeah, please do, because I'm planning to get me all that is needed for a quadcopter ;) , when the weather here stops my projects around the garden (it's weird enough for Austria with random 20°C in November). I've looked around to see other teardowns/photos of the 8-cell version to compare, but didn't find anything useful. 8-cell "fakes" seem to be a lot rarer. The 6-cell versions look completely different on the inside, even those from Turnigy. I guess the only thing that can easily be compared are the soldering quality and component markings of the "fake" ones.
Julian Ilett Getting a fake one is easy I could give you the seller I got my fake one from lol the seller was www.ebay.co.uk/usr/bgood2010 I see their ratings have gone to the sea bed oO but maybe they not selling them now ?
Actually it looks really good. Only few things that are not ok but well i suppose cheap solutions are good also :). resistor network is there instead of one good resisistor .but this one is ok also. cheap solution and easy ..What i don't like is ..instead of flat metal support bar for transistors they could spend few cent more and use I_I this shape so there would be no way to bed it at all..another thing is that coil and those two capacitors are not glued to board and that is not good at all...I think i don't have to say this was made in China because no oficial trademark like CE or what ever ..boad should be date coded as well. but even if it was in China or taiwan..quality is really good ..compared to some CH crap we have on market..Nice teardown
![Quando Rondo - Life Goes On [Official Music Video]](http://i.ytimg.com/vi/eIf3fhMXAow/mqdefault.jpg)
Hi Julian - I have a Bantam eStation 902 charger (two actually because I blew up the first one) - it is built in exactly the same manner, and the bar pressing against the MOSFETs was bent on that one too. I replaced the MOSFETs on the broken one, but it still needs me to replace some op-amps too - I've yet to upgrade my electronics tooling to handle doing surface mount packages, so it's been sitting on a shelf for nearly 4 years now waiting for me to finish the repair. Thanks for another interesting vid. Cheers!!
As always, something I probably would not do, but always enjoy your thoughts and thinking
Thank you kind sir.
I wonder if that bar was also drawing some of the heat away from those devices, which it surely isn't doing any more with the addition of those rubber feet.
Your practical mind always impresses me. Rare for an typical engineer
If you want to add a temp sensor, the receptacle looks the same as my imax b8+. With the thermal sensing, it has worked great detecting overheating Li-Ion batteries and halting the charge before it went critical. "TS-474002/11777 Temperature Sensor w/ Futaba plug" was what I got. It's got a curved magnetic side that's perfect for Li-Ion's. I'm still searching for how to reduce the LiPo maximum charge voltage because 4.2V is actually hastening death of the cells. 4.1V gives longer life. It could be accomplished through the secret calibration mode but that affect all the battery voltage readings.
Thanks for the partnumber. In my country I couldn't find it with that partnumber, bu I could with this one: Futaba SBS01T.
It's also an 3-pin temperature sensor (White/Red/Black or vice versa).
For anyone reading, all you need is a generic 3-pin sensor, 2 pins for supply, one for readout. My guess is it runs on 12V but I don't yet have a sensor, nor have I tested it.
Wow, good thing there was the warning, otherwise might have never found out about this shoddy heatsinking!
Thank you for the inside look, especially on how to get the buttons out. My buttons are sort of malfunctioning...they work intermittently and I'd like to replace them. Any idea on how best to go about it? I find that if I apply extra-firm pressure to the buttons they work, but "regular" pressing doesn't really work.
dequinox they're just pcb-mount tactile buttons, if you desolder the 4 pins it should come out.
I had the same thought. It seems this would actually insulate (keep in) the heat in the front side.
Nice video Julian. Welcome to the wonderful world of HK. there's a reason this stuff is so cheap and you always stand a 50/50 chance of getting stuffed when you use them.
Quick bit of info, the large array of resistors on the right is for balancing
Destroyed a tact button pulling off the buttons that way, but lacking any other alternatives, you might as well plan on replacing all 4 buttons with a breakout board.
So you've made it better while voiding the warranty. :) I wonder if those rubber/plastic feet will hold their compliance or cold-flow over time and reduce the pressure they apply to the to-220 packages?
I just bought two of these off Hobbyking and would you believe, the bars are also bent on mine as well. They must churn these things out by the thousand and not care about thermal efficiency. I'll have to rip mine open to bend the bars back into shape at some point.
Hey there, thought I would open up my Accucell-6 as a comparison. Pretty similar construction although the mosfets are on the bottom, certainly close enough that you could call them siblings. But the thing I thought you might like to know is that there are no manufacturer name markings on the PCB of mine either, so that too is consistent at least & I'm pretty sure mine is genuine. I would say that your one simply passed through a Quality Controller who had a rather liberal interpretation of their own job title/description :)
The only hint i had that it may be authentic was the fact that the LCD can be detached thu a plug , usually for cheapness they wouldent do that and solder it directly to the board. You may want to monitor it using a alternative multi meter device to see if its safe during charge.
Genuine IRF mosfets usually have a mark on the inside of that circular "stamp" on top of the plastic case. So these look like fakes to me.
Julian Ilett hi, i was slightly worried when you put thee rubber feet on, i know from experience that the charger can get rather warm, and i am worried the rubber would melt and maybe cause a fire hazard...
whats your thoughts on this?
Is there any reason you can't drill and tap mounting holes for each semi on the heatsink doing away with the bar totally? It would be a bit of work but would be a lot more robust both thermally and mechanically.
It occurs to me that and an angle extrusion rather than flat bar might have been a better idea for the MOSFET clamp - more resistant to bending. Turnigy's bodgery on the mechanicals is world-class on this one!
Marcus Jenkins I used this method a while back in my grid tie inverter. That did have a U-shaped bar (quite a shallow U) across all the MOSFETs and diodes. But it was susceptible to bending just the same.
Hi Julian.
I'm new to your channel and loving it..
Going by the bodgery in your charger, have you thought about getting one of the knock-offs to see if they're really that bad?
breaksbassbleeps Yes, definitely. I mean, how much worse can they be?
I hope those mosfet pads will hold up to heat, as you said, heatsink gets hot, mosfets even hotter. What do you think, will you check?
First2ner I'll keep an eye on it - particularly when I start charging at high power levels.
Discharging actually makes them get the hottest compared to charging.
By adding the feet to the metal bar. aren't you now preventing (to some degree) additional heatsinking the bar may have provided ?
The To220 package is cooled by heat transfer through the metal tab at the back. Sure, a small amount will also pass through to the front, but I reckon the improved thermal coupling between the component tabs and the heatsink extrusion, far outweighs the loss of the metal bar at the front.
i've had 2 imax B6 chargers so far and people are always debating in the comment section weather they are fake or not, it doesnt really matter. first off even the "fake" ones are still pieces of equipment that work, by "fake" it sounds like they mean its just carved out of a block of wood and doesnt do anything. also the "real" imax b6 chargers are made in china and are shitty just like the fake ones. if somebody really wants quality they need to build it themselves instead of paying 30$ on ebay.
yeah unfortunatly its the way the world works these days. recapping cheap shit with rubycon caps always helps and putting better mosfets in works too.
Hmmm. Seen as they've likely had the case profile made, a small detail would have allowed the use of those snap-in clips to hold the devices on to the heatsink. Better performance and faster assembly too.
I've seen u-section strip used with this screw arrangement, but also with a screw in between each device. Someone clearly doesn't have a clue.
Maybe that's the same person saying that the failing units are fakes?
Let's face it, not everyone will be running the unit at the limit of it's claimed spec. So their units will survive a little longer.
Simon Parkinson I think a screw between each semiconductor would be the best arrangement.
Julian Ilett Costs a lot more to produce as each device would require a screw, sil-pad (placed accurately on hole), top hat and testing of continuity to chassis.
Note to self
The pinout of the Power Supply side is shown here: 5:10
Flip the board over, Mosfet side to self where the supply holes should be at the bottom right. Top hole is positive, bottom is negative.
Hi! I just recently bough IMAX B8+ from hobbyking and it has that same bending bar inside. Tought it would have had a little bit better quality than turnigy but it seems to be almost the same inside.
lookingHK That's actually a really good idea. Might try that!
I like your videos a lot but rubber thingies there on the components, is this really a good idea? Those can prolly get pretty hot on that side too, also there's no way for that flat bar to keep them pressed against the radiator without bending. Even after your mod there is a slight bend to that bar. I'd get a piece of thick square/rectangular alum tube cut it to properly fit(kind of an u shape) and use that for support..., and lose the rubber thingies :) surely more work but it will be more rigid
Great vid Julian, although on seeing the heatsink, I kinda wanted someone to shout "YOU GOTTA BE SH*TT*N' ME!" in an Australian accent for some reason...
Hi Julian, I do not know how warm the MOSFETs of this charger get, are you sure that those are rubber feet and not plastic feet that will melt?
I hope they don't melt. Now that the MOSFETs are properly thermally bonded to the heatsink, they should run cooler.
The charger will shut down before anything melts. There is a NTC-resistor on the heatsink that controls fan speed, and shuts down the unit if it gets too hot.
***** Good point!
The mosfets still get quite hot when charging a 5A + charge rates on these chargers, so I also be concerned the rubber feet melting... they're not exactly meant for high temperature situations! That being said, i have a hobbyking 4 way charger, a genuine iMax B6 + plus several turnigy accucell 6s - none have failed yet. Worst thing that's happened is failing buttons that have needed cleaning.
Peter Feerick Julian Ilett I believe rubber melts between 150 C and 300 C depending on the rubber so well above what those MOSFETs should safely operate at. However, some plastics have a melting point of as low as 70 C which is a bit worrying. So as long as this is a good quality rubber, it should be OK.
The bar needs to be reverse curved, so that by the time there is enough screw force to straighten it out, it is applying uniform pressure across all the devices.
jpopelish That would certainly help. But to work reliably, it needs to be thicker. Component clearances would start to become an issue then though.
Julian Ilett
And it would help if it was made from a springy material, instead of aluminum.
Julian Ilett You should have been changing the capacitors
I noticed the unpopulated usb mini pads on the right. Maybe the usb functions are already there, but only the socket is missing?
What's odd about the USB socket pads, is that only two of the pads appear to be connected up. I can only assume that these are Tx and Gnd, and that it's not really USB at all. It must be a serial data stream and require a FTDI-type USB/serial converter cable. I guess I could put my scope on the data pin and see if it's squirting out data bytes.
Do they have any 27ohm-ish resistors on D+ or D- ?
John Knutsson It looks to me like pin5 is grounded, and pin3 goes off to the microcontroller - no other pin is connected. I'm using this as a reference: forum.sparkfun.com/viewtopic.php?f=19&t=33227
Julian Ilett
That is pretty strange. It will probaly be serial then. It would be interesting to know what it puts out.
Julian Ilett Exactly. It's quite common for these chargers to use TTL Serial over USB, requiring a special cable.
Those rubber gasket heat transmissive pads as you call them are called Sil pads just FYI
Great video
Not to related to the video. But I'm looking for the cheapest way to go about setting up a battery backup. Doesn't need to be super reliable . I'm thinking about getting a couple 50 watt solar panels and a few of those cheap eBay charge controllers. With a 500 - 700 watt inverter. I'd probably only ever use 200 watts for more than 15 or 20 minutes . I just want it to have the capability of running my mini fridge if I have to use it for that. The hardest part is finding cheap batteries. I want it to have a battery bank with a decent capacity
YEEEEEESSSSSS!!!!!!!!
I also noticed the usb. you should solder on a usb and test it on an old laptop, something that isnt really worth much.
***** I might solder on a small bit of wire and scope for a serial data stream.
Julian Ilett good idea. It is entirely possible that everything is there. It looks like the jumpers for the power are there.
Julian Ilett The USB is for a Temperature Probe I got one from china but someone in china wired it up the wrong way around I reversed the wires and it works before it was reading 70C in a 20c room lol I refer to the 3 pin terminal on the left.
send this video to hobbyking and show them what they're actually selling.
the only possibly looking genuine IR mosfet in that pack is maybe the one next to the 5v reg, it has the usual half round ears cut into the tab,
Most IR fets have a cut that from the top down goes in at a sharp angle and then curves back out, like a semicircular cut with a flattened top
Getting genuine mosfets is hard, I even had some from an ebay seller who was getting them off one of the UK main component houses, but I Really Shouldn't name them.....
Your 'spacer fet' looks genuine IR
any views on rubber mat insulation/thermal performance over old mica insulating with thermal compounds ?
I've never liked rubber, to me its an insulation....
I recently bought an IMAX was very unhappy with it as it was a FAKE and the voltages where off by about 700mv that might not seem a lot but when charging LION cells it can be dangerous, I complained to the Ebay seller and got a full refund, plus I pointed out to the seller that selling counterfeit goods is a crime in the UK and even distributing them is a crime, as a result I was not asked to return the item, so got money back and got to keep the IMAX..
I later bought a TURNIGY ACCUCELL 6 with my refunded money from Hobby King and it is much better, but never got a user manual or pretty box was bare cardboard :p
My trunigy 8150 charger goes off after couple of minutes.. does any one have any clue what to go check. the power adapter is fine and it works well with my other charger
I have a question not regarding to this charger:
I got a couple of LEDs from a friend wich he doesnt need any more. They look similar to this: s1309.photobucket.com/user/99freezone/media/ebay%20%20pictures/FZ0340-03_zpsf27beb98.jpg.html
Now how can I tell if they are 1W or 3W LEDs? (he can't tell either)
I mean I could apply 700mA to one, an when it blows up, then its an 1W LED, but are there better ways to find out?
Seeing that, how much worse can it really get with a "fake" one? Since the board is totally unmarked, I think it's the typical "one product, hundred labels" item.
superdau I'm keen to get a 'fake' one now, to compare.
Julian Ilett
Yeah, please do, because I'm planning to get me all that is needed for a quadcopter ;) , when the weather here stops my projects around the garden (it's weird enough for Austria with random 20°C in November). I've looked around to see other teardowns/photos of the 8-cell version to compare, but didn't find anything useful. 8-cell "fakes" seem to be a lot rarer. The 6-cell versions look completely different on the inside, even those from Turnigy. I guess the only thing that can easily be compared are the soldering quality and component markings of the "fake" ones.
Julian Ilett Getting a fake one is easy I could give you the seller I got my fake one from lol the seller was www.ebay.co.uk/usr/bgood2010
I see their ratings have gone to the sea bed oO but maybe they not selling them now ?
That "component with leads clipped off as spacer" is what china did for our solar grid tie inverters.
Actually it looks really good. Only few things that are not ok but well i suppose cheap solutions are good also :). resistor network is there instead of one good resisistor .but this one is ok also. cheap solution and easy ..What i don't like is ..instead of flat metal support bar for transistors they could spend few cent more and use I_I this shape so there would be no way to bed it at all..another thing is that coil and those two capacitors are not glued to board and that is not good at all...I think i don't have to say this was made in China because no oficial trademark like CE or what ever ..boad should be date coded as well. but even if it was in China or taiwan..quality is really good ..compared to some CH crap we have on market..Nice teardown
SylwerDragon I'm wondering whether the resistor matrix might actually provide more accurate resistances, from a statistical point of view.
ofc it does. That is why all modern multimeters use one resistor instead of so many cheap ones...But that one resist network cost much more..ofc.
Love your vid
After your magical touch and BSI Quality Assurance, is it still not genuine. Because you have forgotten to write your own Serial No. hahaha.......
It is so stupid. One hot mosfet makes hot all the other ones.