Maybe somebody else with a evolve GT can test and share the values with us. I really would be interested at which voltage under load the board switches automatically to ECO mode.
Honestly, this whole endeavor isn’t really worth it. The deck isn’t exactly flawless either. There have been multiple cases of random cracks in the carbon fiber.
The value on these things are quite high still. You could try selling it and going DIY to get exactly what you want. Modifying your expensive board with a bunch of issues will probably end in a money pit.
You’re probably right, but I will have to point out that they did a quick revision of the board after the first batch. The cracking is said to have been fixed. Maybe its the sentimental value since its my “real” first E-Board or that I spent so much time working for it, but I really love the board. I find it has plenty of power, the remote is awesome, and even for going distances, the board is fine until it reaches 50%. 12 miles is plenty. Granted, I don’t plan on doing any major modifications except making a 26T gear until maybe its truly necessary.
LiPos vs LiIons
If you go with LiPos, Pros You will have no power issues at all, the discharge curve for LiPos is very flat (4.15V at 95% and 3.5V at 15%) so your performance throughout most of your ride will not vary until your batteries are about 15% when the voltage drops extremely fast 3.5V to 3.0V empty). Since their internal resistance is low you also do not get a lot of voltage sag. Cons You have to get a new VESC and BMS. The BMS on the CGT is meant for Li-ions and if it’s really just a voltmeter measuring capacity, it will tell you you have 20% left when your LiPos are completely dead. You also have to make sure that whatever setup you get fits within the CGT compartments. Lastly, you won’t have as much endurance, a 10S 8Ah battery like @evoheyax suggested only has 288Wh.
If you go with LiIons, Pros You can keep your current BMS and VESC. The cells are very likely to be the same size as whatever is in the compartment already so no need to worry about a 10S4P pack fitting in. If you get a VTC6 pack like I suggested earlier, you will get more endurance as the pack has a total of 432Wh. Cons You will still have some power issues, not nearly as bad as you do now but basically the discharge curve for LiIons decreases linearly from about 4V to 3.2V from 95%-20% at which point the voltage drops fast (3.2V to 2.5V empty). The VTC6s are known not to sag much but they will still sag more than a LiPo.
Both options would be pretty expensive, ~$350-450
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Thanks for the comparison. I’m trying to keep my BMS+VESC because of its compatibility with the remote. The VTC6 seem to also be rated at 10a - wouldn’t that mean they would have the same issues?
VTC6 are rated up to 30A/cell as long as you keep them under 80C.
Here’s a graph of the voltage sag so you have an idea. The cells in the CGT are probably knock offs of the samsung 25R that a lot of people around here use.
In this graph, red is 25R and blue is VTC6. Top curve is 0.2A which is close enough to no load. The next one down is 1A, then 5A, then 10A and finally 20A continuous.
As you can see, VTC6 sag a little less when at 20A than the 25R at 10A, yours being knock offs are probably slightly worse.
You can also see that at 50% capacity (1.25Ah) 25R are at 3.7V pulling 0.2A and they sag down to 3.1V pulling 20A, which is probably what you’re seeing. VTC6 at 1.25Ah go from 3.8V pulling 0.2A to 3.4V pulling 20A.
In reality, motors are a power load and not a current load so the sag at equivalent power levels is slightly lower for the VTC6.
What you see is worst case scenario
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When did you get your CGT? I guess I am just lucky, living only a few hours from Evolve US, I was one of the first non beta testers with a CGT and I haven’t had any issues (minus the motor pulleys eventually wearing out). 1500 plus miles later and everything works flawlessly (I do live in a flat area tho).
I have never noticed the board going into eco mode on it’s own. Maybe it’s for newer batches of CGTs. On a few occasions, I rode the board till it was pretty much dead lol and I was in GT mode the whole time. Also, it didn’t just instantly go from 26mph to zero mph when it died. (Side note, I even use bigger motor pulleys so I go faster than 26mph and I still feel really safe at lower battery percentage)
Edit: off topic, but let me add, after riding my Trampa build from Bara, I feel way safer on the CGT lol. The Trampa build is not only powerful but riding on ESCs compared to a commercial board is a night and day difference . ESC acceleration and braking is scary.
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Don’t get me wrong. I love my CGT - not even remotely regretting purchasing it. From what I know, the voltage sag issue is widely accepted as being in all GT boards but it really only caused issues once the batteries drained to 50%.
When the first batch of GTs came out, there were two main issues everyone was talking about. Engaging reverse being too easy while riding and voltage sag to the point where the board shut off. The first issue was fixed by sending out remotes with new firmware (you can get yours updated if you send yours back as well) that required multiple clicks to switch to reverse - thus eliminating the problem.
Voltage sag has always been talked about as the battery percentage going down during hard acceleration confirmed this. The first batch had the board shut off when in GT mode and accelerating since the battery couldn’t handle it - I imagine this would just make the board coast to a stop but its still an issue. This was resolved in the same firmware update mentioned above by making the board switch to ECO mode when the battery sags below 20% to avoid shutting off or damage to the cells. This may also help with range when the battery genuinely falls below 20%.
I’ve never heard of a case like yours where everything is flawless. I’d love to find out what changed if yours is perfect. Also, about the motor pulleys, I’d like to increase the speed as well - could you help me out and tell me what you did and what kind of speeds you’re reaching? I wanted mine to hit 30mph, so I planned on making 26T gears for the wheels but I’d love to hear what you did.
Oh I love my CGT as well. I also love my Trampa build, it is a beast in every aspect. However, for daily use, I use the CGT for a few simple reasons, size and weight and I also don’t want to wear out my Trampa tires lol. Urethane wheels just seem to last forever.
Crap, forgot to add that the only other issue I had was a BMS issue only after a few days of owning my CGT, I sent it back and it has been working flawlessly since then. I would be pretty damn pissed if my board just shuts off from hard acceleration. I would think I would have experienced this by now as I ride my CGT very aggressively.
I haven’t had any issues with accidentally pressing buttons lol. I even wear gloves at times.
My main interest at this topic is the board switching to eco mode. I would totally hate this. Mine stays on GT mode even say at 20% battery life. I should take a video but I am too lazy on video editing and uploading lol.
You can probably find out more about the reasoning behind the update by talking to Evolve AU as they are the ones that issued it.
Could you tell me more about your gearing setup? I’d love to hear more about it as I really want to be able to go a bit faster on my board.
Its ridiculous how in-depth you guys go just to help a random dude on the internet like me. Seriously, thank you so much.
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Yes I know how it works, but from you post I thought you were connecting the same pair of batteries in parallel and in series. Now I understand there’s actually two pairs! 
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The Bamboo Enclosure fits 40cells, so assuming the Bamboo GT is 10S4P with 6,5Ah that would mean 1625mAh per cell but 25R is 2500mAh… If it’s a 10S3P, you could go up to 10S4P to decrease the sag.
Same with the Carbon GT, could be 10S5P or 10S6P.
http://i.imgur.com/d3AR7fV.jpg looks like 5P…
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What are the dimensions of the battery?
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@VikasG had stated it’s a 10S4P 360Wh pack. Each cell is 18.3mm diameter and 65.1mm long. Measure the pack and you can figure out how many cells are in there…
@E-Boarding Plus your numbers are not making any sense. 25R is 2500mAh not 2500Ah and I have no clue where you’re getting the 16250Ah number from
About the LiPo vs Li-ion topic, I created an informative thread about it already:
There was no interest in it tho…
I’m reading that there are 40 cells so it would be 366mm/36.6cm long for just the cells and no wires. Since 20*18.3 = 366.
Weird, I feel like that would one of the most debated topics. Maybe another thread regarding the same topic was created before?
To measure the physical size would be helpful.
That’s my photo from my tear down. This issue has literally been beat to death… I really feel like people don’t understand… I read your original post. Honestly, if you are smashing around full throttle on GT mode and you’ve already traveled 12 miles(like you said in your original post) you have to understand that your battery really isn’t at 50 “percent” charge.
I feel like that situations have less to do with Voltage sag, and more to due with people not understanding that you’ve probably depleted 80 percent of your battery capacity by that time. I can drain my battery on my CGT in 8 miles if i wanted to, or i can make it last 25 miles and take it easy. I can do the same thing in my car with gas… I could make this same argument with the gas gauge in a car. The same car can get 5 MPG, or 25 MPG, just depends how you drive.
Evolve is probably the only company that uses a battery percentage display(since they are the only company with an LCD remote out currently) and I feel like if other companies offered this, you’d see this complaint far more often with other brands and manufactures as well. Feeling like it really bit them in the butt, because some people just don’t understand how it works and calculates that percentage, I personally love the percentage display, and after having the board for less than a month i can actually use it to get a pretty good gauge of how much distance I have left.
The only real feasible thing you could do is research the HIGHEST QUALITY, HIGHEST CAPACITY, HIGHEST DISCHARGE RATING 18650 cells you can find and builds a custom pack to those dimensions. I believe you’d be surprised though…even if you did that you’d spend way more money than you’re expecting just to get a lackluster result that is MAYBE a little bit better. Just my two cents…