AVIAN featherweight mid drive

SlowCo said:
:shock: Wow. Fantastic workmanship!
Now waiting for a ride review and video 8)
Not so fast eager beaver. I still need to wire a BMS, a fuse and a power switch. :D
 
I took the bike on a single track around Lake Miramar. I was very happy with everything, but had one little problem. Under heavy load, I was getting a hick-up. It was hard to tell what was going on, but once I put the bike on the hydraulic trainer and applied the rear brake, I realized that under heavy load my motor chain tensioner was going a little out of alignment, and the chain was not perfectly in line with the chainring. Under normal circumstances, this wouldn't be a problem, but I had very little space between the chainring and tensioner, which it turned out that this was not good.
I decided to reverse the tensioner and the problem is gone.
At this point, the total weight of the bike, including the battery, is 46 lb. My goal was to be under 50 lb. so I'm happy with that.
I will play with the bike for now, and install a bigger motor later. It is actually amazing how well this little motor is running.
Avian with reversed chain tensioner.JPG
 
All aluminum parts for the battery case and the controller case are at anodizing process.
I switched my focus to the battery system. I'm going to install a 16A BMS just for charging and two battery testers for monitoring battery voltage. This way I will be able to keep track of battery group health individually. VESC will control low voltage of the pack. With VESC you can program both soft and hard battery cut-off voltage.
 
Parts are back from anodizing and the battery pack is back together. I installed the anti spark connector and two battery testers. Unfortunately, the cheap BMS was not working as it should, so I ordered a new one, and I will plug it in once it comes.
I still need to install the meter switch and total voltage meter. This is going to be my fuel gauge.
The pack with testers..JPG
 
Ecyclist said:
Parts are back from anodizing and the battery pack is back together. I installed the anti spark connector and two battery testers. Unfortunately, the cheap BMS was not working as it should, so I ordered a new one, and I will plug it in once it comes.
I still need to install the meter switch and total voltage meter. This is going to be my fuel gauge.
The pack with testers..JPG

Just an FYI, I went through a similar process in monitoring/controlling power but ended up simply installing a Cycle Analyst (CA3) to do it all and more (I.e.: adding Pedal Assist mode).
 
Mongo1 said:
Ecyclist said:
Parts are back from anodizing and the battery pack is back together. I installed the anti spark connector and two battery testers. Unfortunately, the cheap BMS was not working as it should, so I ordered a new one, and I will plug it in once it comes.
I still need to install the meter switch and total voltage meter. This is going to be my fuel gauge.
The pack with testers..JPG

Just an FYI, I went through a similar process in monitoring/controlling power but ended up simply installing a Cycle Analyst (CA3) to do it all and more (I.e.: adding Pedal Assist mode).
Thanks for the tip.
I have CA3 on my first build and I like it for smoothing out power delivery, but that's about it.
I can use VESC for that and everything else I need (probably not Pedal Assist mode, but then again, maybe someone already figured that out).
I like to have battery meter and testers, so that I can monitor battery charging process indoors and away from the bike.
I don't trust BMS, and with testers I have full control over what is going on with the battery. You can call me a control freak. :D
Are you sure that you can monitor individual battery groups with CA3?
I probably should revisit CA as a possible option. Last time I looked into it was about a year ago.
 
Ecyclist said:
Mongo1 said:
Ecyclist said:
Parts are back from anodizing and the battery pack is back together. I installed the anti spark connector and two battery testers. Unfortunately, the cheap BMS was not working as it should, so I ordered a new one, and I will plug it in once it comes.
I still need to install the meter switch and total voltage meter. This is going to be my fuel gauge.
The pack with testers..JPG

Just an FYI, I went through a similar process in monitoring/controlling power but ended up simply installing a Cycle Analyst (CA3) to do it all and more (I.e.: adding Pedal Assist mode).
Thanks for the tip.
I have CA3 on my first build and I like it for smoothing out power delivery, but that's about it.
I can use VESC for that and everything else I need (probably not Pedal Assist mode, but then again, maybe someone already figured that out).
I like to have battery meter and testers, so that I can monitor battery charging process indoors and away from the bike.
I don't trust BMS, and with testers I have full control over what is going on with the battery. You can call me a control freak. :D
Are you sure that you can monitor individual battery groups with CA3?
I probably should revisit CA as a possible option. Last time I looked into it was about a year ago.


Sorry, no provision to monitor separate battery groups (only different/switchable battery packs, I.e.: 36V, 48V, etc.)
 
I can't wait to see the follow up with 80mm motor :D
 
At this point, the bike is running on 6374 3200W Alien motor and is a real joy to ride. I have an 80 mm 6000w Alien motor that I'm going to use.
http://alienpowersystem.com/shop/brushless-motors/aps8072s-sensored-bldc-motor-165kv-6000w/
The problem is that I had the flu and was in bed for 5 weeks, and now I have to play catch-up game with my regular work and make-up game because I will be going for a 4 weeks vacation. So, the the bike build is on hold. Life is rough. :D
 
Ecyclist said:
Unorthodox way of the balancing battery pack.
looks like you did connect all groups in parallel. why not :) , but why you don't add a BMS?
 
madin88 said:
Ecyclist said:
Unorthodox way of the balancing battery pack.
looks like you did connect all groups in parallel. why not :) , but why you don't add a BMS?
This is my second pack. My first pack had a BMS, but it was doing bad job balancing the pack so at this point I'm using battery testers.
I'm still wired for a BMS.
I took a look at your build and I'm very impressed. Can you recommend a BMS for 10S and 60 maybe 90 Amps?
What BMS are you using now?
Thanks!
 
notger said:
Ecyclist said:
Can you recommend a BMS for 10S and 60 maybe 90 Amps?

As Examples

http://www.chargery.com/BMS16.asp

https://bmsbattery.com/bmspcm/833-smart-bms-10s13s-60a-with-blue-tooth-android-or-ios-app.html

or from the E-skate community

https://www.electric-skateboard.builders/t/diy-6s-to-12s-bms-with-can/2639

and probably there are more interesting opensource BMS project out there

greets Notger
Thank you Notger!
That esk8 BMS looks great. I will give it a try.
 
I put myself on the list to buy one or two of these esk8 DieBieMS BMS. It looks like it will take a while to get commitment for 50 units to manufacture the next batch.
I was very excited about getting those puppies, but all that evaporated by now. So far, they sold in the past about three dozen of these units, and users who own them are having all kinds of questions (read problems). Builder and seller (two different guys) are not willing to come up with clear instructions. It is a cool project, but it can be PITA in real life situation. Other 60A and up BMS boards are too wide for my case.
I decided to electrically split my battery pack. Now I can charge it bulk with 42V charger, or I can balance charge it with SKYRC iMAX B6AC hobby charger. I need to do it about every 30 charges, and with this set-up I can go up to 12S, if I want to. I can control amps. with VESC and I monitor cells with small volt meter and two battery testers / loggers. All cheap and bomb proof stuff.
I use XT-90 Anti-Spark Connector for bulk charging and power delivery and two XT-60 connectors for balance charging.
From my perspective, this is the best set-up.
 
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