Ok thx… i will try to order it .
i will try something out… ill will try to put some batteries in by still using the old charger, http://www.aliexpress.com/w/wholesale-3.7v-10000mah-battery.html just need to finde some batteryes there can fit inside the olde case 
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Don’t mix the cells and I’m not sure the Yuneec BMS is flexible enough to be used with alternate battery cells. Have you built a battery pack before (I can give you some pointers)?
Hi, i have two yuneec boards but one has connection issues. Could i combine them to make a diagonal drive driven by the same battery? I figure that with the ESCs limited to 15 amp each I would not pull more than 30 from the battery. It would be a heavy board but may handle the 12 degree incline in my neighborhood more easily. No idea about top speed, but more than 11mph… Any thoughts?
@anon94428844 I’m thinking about doing this myself, but I did have a couple clarifying questions–
Was the top speed changed at all with the VESC or is that still limited by the E-Go’s battery voltage?
The 26 miles you mentioned I imagine has to be with charging (you say “2x 15 minutes wall plugs around 25v”). Did you really only charge for ~30 minutes to go the 26 miles or am I completely reading that wrong? Even though the E-Go battery is pretty big, that still seems like a lot of distance w/o at least one complete charge…
Also, regarding braking with FOC-- is it noticeably different than the power of the stock E-Go brakes? I was doing some reading and it seemed like w/o the Hall sensor working, only the regenerative braking works.
And one last one-- the BMS is connected to the E-Go battery, right? If that’s true, then would this mean that you can still use the existing power switch and wall plug?
Thanks in advance.
Sorry, I didn’t see this reply. The original cells in the 7s3p battery have a max contjnous discharge port cell of 20amps. That said, I rode single at 30Amps without issues - but check your motor for cooling issues. The voltage will affect top speed, but these motors are wound with a low kV (which means that your top speed can be influenced also by the current you pump through them).
When I burned out my original Yuneec ESC, I was going close to 30mph up hills with this battery. With the VESC limited to 70Amp from my custom battery (cont.disch of 70, pulse 120) and 20Amp motor for 10s, my max speed is something like 14-18 mph. If I push my motor current to 30Amp I get more speed but I stress the motor more.
No, that’s accurate. The original ESC battery cut offs might be higher that mine. My VESC cut offs are based on Cells @ 3.5V and 3.3V. Additionally I was riding in DC with flats and hills (easy regeneration, my Nisan leaf (poor 70 mile battery) doesn’t lose much battery in town except via climate control). I also am light enough that I d get about 18miles with the original ESC.
I’m using sensorless FOC quite successfully and more smoothly than the stock ESC. I will say my settings confuse me. My regen starts at -160Amps and that give me a smooth, gentle stop at any speed (my custom batteries are LiFePo4 which can take a lot of abuse if the regeneration is ever that much). I can’t get the hall sensors to work (I’ve tried wiring them in different configurations all to the same effect. If you get it right, lmk?) But they have no effect on the performance it would seem. Smooth. And quiet at low speeds, same at 19mph.
That is correct. I hope to but a 10s2p setup in this space as well.
Boards - Stock + Modded (VESC + Wattmeter + 10s4p custom)
Yuneec Original Battery
Yuneec Battery Cells - NCR18650PF, 2Amp Cont.Disch
Yuneec Battery Cells - BMS + Balance
Anyway, you can also see the placement of the thermal sensor in the photos (middle black blob).
If y’all want more pictures of either boards parts, let me know. I can’t open the damaged motor I have caused the grub screw is stuck, but I’m cutting the shaft soon.
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The cells are rated 10Amp max discharge. So 3 parallel cells should be able to provide 30 amps. Here are some specs I found on these cells : http://www.rc-electronic.com/downloads/pdf/infos/datasheet_LiIo_Panasonic.pdf
Whoops. I gave the amps for the VTC4s I just ordered.
Huh, very interesting. I may just try it out then. I just was going around a trail around here (perfectly flat, around a lake) and got ~11 miles before I had to leave, but if I remember correctly I got the low battery controller vibration around then, so I only get around ~12 miles total. I’m pretty light, so I’m a little surprised I don’t get a little more range.
Even if there’s a marginal improvement using the VESC and stock battery to bump up the range to their old 18 mile claim, it’d be worth it to me to perform the mod. Later down the line I might swap out the battery too but at least this would get me half way there for now.
Thanks for posting those photos, and I’ll let you know if I can get the hall sensors working. I’ve seen at least one person claim he was able to get it to work (on EndlessSphere), so it might be possible.
Yep, Jacob worked on these a while back and said that it just work with the VESC.
I ordered a spare cable for the Yuneec motor. They’re expensive (i paid like $36 shipping included for the pair) and I can send a JST set to you for $15. Are you in the USA or elsewhere?
Yeah, I’m in Washington state. Is that the 9 pin waterproof cable you linked to above, or is it the JST cable for the Hall sensor?
I would send you both.
That would be fantastic! Do you have an email address or something I can contact you at? As far as I can tell this forum doesn’t have any sort of PM functionality, but I might just be missing it…
K********@***. edu
I usually reply within a day or so. I’ve been busy at the office. I’ll get back to you tonight.
Great, no problem. I really appreciate your help.
I recently purchased two yuneec e-go from ebay. One was in perfect working order and the other one had “connectivity issues” according to the ebay listing. Well I finally had a chance to open up the defective e-go to see what was the issue.
The connectivity issue was actually a defective battery. The board didn’t turn on. The remote control that came with the board worked perfectly with my first board.
I opened up the battery and here is what I found. The BMS had some of the FETs (or diodes?) melted of from the solder from their base. They had also melted off the blue plastic shrink wrap that held the battery together. I soldered the FETs back on but that did not fix the battery. Next I tried to charge the battery but it had no effect.
I checked the battery voltage and it was 6.2 volts on the blue EC3 connector. This is waaaaay too low for a 7S lipo, it comes out at less than 1V per cell. This means that the cells themselves are completely discharged and, I’m afraid, beyond salvageable (I think?).
I also checked the fuse in the battery. Its a 30Amp fuse. The fuse was in good condition and had continuity as confirmed by the cell voltages. The 30 Amps was as high as Yuneec designed the battery to output and I can assume the ESC should be capable up to 30 Amps.
I checked the ESC and motor by unplugging the battery from the working unit and they work perfectly.
Therefore, I’m left with a Yuneec E-GO that only had a bad battery/BMS.
I’m thinking of getting three (3) lipos with 3000mah to 5000 mah and a cheap lipo balancer to function as my bms. That way I can build a lightweight 9S1P battery and be over the original 7S but below the 10S people say burns the ESC. Hobby king sells a balancer board where you can plug in up to 6 batteries and they will all charge while balanced. I plan on getting a super cheap balance charger from turnigy for battery management.
I’m planning on using the original switch and the VDC input jack to power the lipo balancer to charge the battery. I’d need a new 12 VDC wall adapter as the cheap turnigy balancer will not take the 29 volts coming from the original yuneec wall adapter.
Also, the drive wheel is overmolded onto the gear itself so there is no way of removing it. The wheels themselves are not particularly heavy or bad. I may end up keeping them.
I may change the bearings for biltins.
The deck is actually flexible once the battery is removed. It is also not particularly heavy. I think I can reuse it, but I would attach the batteries and cover in a way that does not hinder the flex. Otherwise I may get a Never Summer Heist board which is super flexible and really light.
Any ideas suggestions are welcome.
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Hiya!
Did you notice how the Yuneec BMS has an open balance port on the BMS? I’m building a BMS based on their slim, pretty board using the higher voltage version of the Texas Instruments; BQ77908A Multi-Cell Lithium-Ion/Polymer Precision Protector (http://www.ti.com/lit/ds/slusav5a/slusav5a.pdf). To be honest, 7-8s is the safe range to keep using your Yuneec hardware.
To reuse the battery pack case (power switch and jack), you should make sure to really fill in the area around the switches/ports with hot glue or waterproof kitchen caulk (to prevent water damage). The switch CANNOT BE USED DIRECTLY TO CONTROL POWERFLOW. To use it, you connect it to an antispark switch/circuit that acts as a relay (otherwise your switch will be a instant flash fire hazard). You can disassemble a LiPo pack and fit it into the Yunneec’s cabin, but you’ll have to make sure its safe from puncture and water and that all of the parts fit.
In your position, I would suggest you ask someone to vacuum form you a box for just the batteries and antispark switch and run battery wires over/under the board. I have one working yunnec battery, a battery shell, and a 10S I’m using with my fully modded Yuneec. If you end up deciding you don’t want the Yuneec battery shell, I’d be happy to take it off your hands - they’re flexy enough to fit some firmer boards.
Swapping the bearings is a good idea - but you should remember that some cheap bearings can be pretty effective.
While you have the yuneecs as they are, put ducttape under the ESC and cover up points where water can leak in (Bottom, LED side, and switch side). Yuneec should not be able to say that you can ride through puddles/rain.
Hi, I’m a bit confused here sorry!
What kind of speed were you able to achieve with the stock battery + a VESC?
Thanks!
I weigh 128-130 lbs, so my speeds were more or less 15mph.
With the VESC using FOC Sensorless I could power the motor up to 20Amp (which is 2/3rd the Batteries 30Amp fuse). That took me like more or less 17-18 mph and infinitely better hill climbing.
With VESC using BLDC sensorless I would power the motor up to 30Amp (100% of the 30Amp battery) and that still only got me to about 18mph (hill climbing was killer).
Increased amperage helps if you need more torque, however it’s not going to increase your speed as much as increased voltage would.
