Thanks for the compliment. About the loop key, To cut power from the Vesc and receiver while charging? Sounds like a good idea. I mentioned in another post that I believe this BMS keeps the pack balanced during discharge as well as charge. I want to test the theory before claiming it as fact and will be doing that shortly. That would be a huge benefit if it does, especially for Lipos.
That is my understanding too. I believe it does keep the cells balanced during discharge. The loop key was needed to isolate the battery and bms, from the vesc. I didn’t like how everything was active while charging.
About balanced discharge: We put 17miles on this build (8s5p) and we still had 42% left. Also, No voltage sag the whole ride. Sensored FOC might be the ticket!!!
The voltage being accurate isn’t the only calculation to get accurate state of charge readings. It is fine for DIY but different batteries have different voltage curves. These volt meters read battery capacity as a linear line. It will be a little off from the curve that batteries discharge at.
http://batteryuniversity.com/learn/article/how_to_measure_state_of_charge
I agree with you that these meters are not accurate at calculating percentage of charge. Thats why I modified mine to read total pack voltage instead. Now I can monitor my pack to make sure it doesn’t dip below 32v under load. And thanks for the link, I bookmarked it.
Outstanding post/project! Now that you can see voltage in real time, how much sag are you getting on the 2p Basen set-up?
The voltage sag on the basen 10s2p was too much for my tastes. Since I do lots of hills. going up this a 10% grade, it would sag 30-40%. Didn’t have the meter mod then. It was ok on flat ground with excellent range. Just no bueno for hills. So now i’m back to Lipos. Check out my 10s1p Lipo build capable of 300a continuous. Voltage sag with this pack on the same hill is only around 10% or less ½-1v This Lipo build was so much easier to do than Li-ions and because of the reduced voltage drop, less amps are pulled from the battery making it go farther with less mah. I haven’t done a full on flat ground distance test yet but I will soon and I’m expecting to be impressed.
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Hi Namasaki ,i’v got 14 volts 00473mah 3s 16p lith ion running on my board but am really dissapointed with the results maybe i’m asking too much and this is on fairly flat ground.whats the minimum capacity that i should be looking for to get best results?if you could help this would be great.
Are you stating this right? 14v? That’s crap voltage…good if you’re a 10 year old
Hi paul, first of all I need you to recheck your specs. 14v 3s 16p 473mah doesn’t really work out . The minimum for esk8 is gonna be 6s (22v-25v) 5000mah
How far you recon the range? Lol to the mail box?
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i’m still on the learning curve for elec skateboards and trying out different voltages etc. me thinking that i could use 14 volts as a base cos this seems to work.but if you say 22 volts minimum then i’m gonna go for that i’ve got two 11volt lipos 3s 10c discharge that i’l lstick in series and see how many miles i get out of it maybe even get to the mailbox AND back if the winds in the right direction.
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at least to the mailbox and back
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Paul, you previously mentioned that your battery’s capacity is 473mah. Is that correct ? If it is then you will need new batteries. At 6s or 22v, you will need at least 5000mah and 20c To get 5 miles range.
Take a picture of the batteries that you are using
This is very much in line with my experience; I get 10-12 miles from 4,900 mah at 12S.
You’ll see a vast improvement in the board at 22v the minimum I would suggest is a 4s setup…it still gives the board some pep
3s is way too low not enough power to the motor to get you going unless you go with a DC motor
i will try it as is and see if i get any more range with it if not i’ll order some more batteries and try and set them on the board so they fit .also i’m using a 270kv alien power system motor is there a problem with the high kv?
No I have that on two builds totally fine for flats a low grade inclines…
At 6s you should be seeing abt a mile per 1000mah
So a simple 6s 5000mah should get you over 5miles and at 270kv you should be able to hit 20mph
I’m not even sure those batteries will work given, they’re fakes. Recycled laptop batteries would probably be a better idea, but even then would require a huge parallel pack.
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