Making a homemade electric bike frame from scratch

[cribby546]

Okay I've spent the past 2 days trying to get my head around the battery charging thing. I am trying to find a way to wire my e-bike so that i don't have to remove the batteries from the frame and possibly reduce the amount of wires i have to remove to charge the bike. I am using 5s 5amp 18.5volt zippy lipo batteries, i was wondering how i could rig them up so that i didn't have to take them out of the frame and also what i would need to buy. Because i haven't bought all of the stuff yet, just 2 batteries atm and will get another 10, i was looking to either wire 2 groups in series to get 111volts or 3 groups of 4 to get 74volts. And i can't friend anything on the forum that is helpful/simplistic....

 

[2007blueprius]

I had an Izip trails, which had about 250wh in the downtube, and at the top had a charge plug and switch

http://www.eco-wheelz.com/catalog/images/izip-trailz-enlightened-electric-bike-2.jpg

here's a pic I dug up real quick, chargeplug is at the top by the headset, switch is on the other side, I still have the frame and the harness, I can get some closeups if you would like, pretty cool bike all wires ran inside the frame, battery could be removed by sliding it out the bottom, 20 large nimh cells 24v 9 ah, they are in my boys go kart now.

George

 

[cribby546]

Does anyone have any experience with wiring lipo batteries in e-bikes because i think I will need every bit of advice you can give me. And also would it be possible to discharge the batteries through a balance board assuming you disconnected the balance lead and connected the parallel batteries to the controller? And also how can i charge the 12 batteries at once without having to fully reconnect them to a charger/balancer? I would like to do something similar to the way the phasor guys have done it? :|

 

[2007blueprius]

I dont know much about this but I remember reading this thread a while back http://endless-sphere.com/forums/viewtopic.php?f=14&t=52240&hilit=lipo+charging+tutorial

should answer most you questions

 

[Tench]

Here is a thread explaining the solution I came up with for re-arranging the pack to parallel charge it.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=39489&hilit=series+parralel+changer

Full details of the bike it was on is in the second build link in my sig, there may be some details on the changer there too.

 

[2007blueprius]

Here is a thread explaining the solution I came up with for re-arranging the pack to parallel charge it.

http://endless-sphere.com/forums/viewtopic.php?f=2&t=39489&hilit=series+parralel+changer

Full details of the bike it was on is in the second build link in my sig, there may be some details on the changer there too.

that is cool, I always wondered why bother with all the balancing, and not do that series paralel plug for the entire pack, so you can have a 4v pack for charging balancing, or a 72v pack for running

 

[cribby546]

I have found that the frame is becoming really rigid, but I have decided to put some internal cross supports to really strengthen the frame against all of the possible stresses and forces the only problem is a small amount of weight is added to the frame. Here are some photos with a bit of heat warp from welding the head tube (which I've fixed)...

 

[cribby546]

Sorry for not posting any photos of the frame lately. I've been so busy with tests that I forgot about the posts. The frame is about 80% complete now, I have made most of the swing arm and frame is bout 90% welded up and looking great. So here are a few photos.....

 

[cribby546]

Here is the most recent photo of the frame with the 6 batteries that I have so far, their is so much more room left for about a total of at least 20 batteries but it all comes down to cost and weight. The frame itself weights about 1.5kg-2kg which is a lot lighter than i thought it would be.... here is the most recent photo.

 

[cribby546]

Here is the frame with the rear shock almost ready to be mounted. Not bad for a 17 year old with no previous experience in bike building.

 

[ARod1993]

Just out of curiosity, would it be possible for me to get the dimensions you're using for the frame?

 

[cribby546]

Here is the most recent photo I just tried thew wheels and forks on today.
If the bike works I might give the plans out but until then ill keep them a secret.
If you click on the photo it will flip itself around...

 

[crea2k]

Check out this guys channel, he seems to be pretty good and knowledgeable when it comes to welding , loads of tutorials on youtube : https://www.youtube.com/channel/UCJAFY2kKKb5sg79yld7T3hA

 

[cribby546]

Anyone know a good company in Australia or China that makes good cheap custom lipo or lifepo4 battery packs around ~72v 20ah ????

 

[cribby546]

The bike WORKS it is such a good feeling when a project that you have spent so much time on ends up working as you want it to, i have just sent the frame away to be powder coated, below is the photo of the frame on its first powered test run. I used 4 zippy 5s 5000mah batteries to test it and the top speed of the bike was around 60kph which was fast enough for me, the frames suspension works great, the reinforcements internally have made the frame significantly more rigid. I will update you when the bike is completely assembled and finished. Hope you like it..... The photo came out upside down click on it and it will flip.

 

[cribby546]

finally done just need the brake lines lengthened... has a max comfortable speed of 65kph with 4 5s lips in series temporarily until the pack arrives.

 

[cribby546]

Took a nice photo of the bike this morning works amazing just waiting for some new brake lines other than that it is by far the best dimensioned bike i have ever ridden on. Any feed back on or thoughts on my first bike build would be great.

 

[tahustvedt]

Looks great. I'm impressed.

 

[crea2k]

Sweeet

 

[cribby546]

Here is the inside of the frame I am running to bike at 10ah 5s zippy lipos at the moment and they seem to do the job really well but I will get more batteries to increase the range later.

 

[Drunkskunk]

Wow. Very nice.

 

[nicobie]

Good job!

 

[cribby546]

The bike couldn't be used for about 3months due to the controller breaking cuts it was a cheap one. I had a new 8kw peak 24fet controller made and it is amazing. I took the bike for a few test runs with some old lips i had and it worked great, then i decided to go all out and get 6+2 more later 6s 12ah packs and wired 4 of them in series to get 100volts which as you would expect was extremely fast got up to 92kph on the flat and the torque was insane. The bike is working amazingly and couldn't be happier.

I would even go as far to say it has beat phasor, but its not bad for a 18yr old who's never built any bike before let alone one that works as well as it does. Over all the total cost to make the bike stuffs and miss orders aside coat around $3500 for a full suspension 60km range 70kph+ speed isn't bad, defiantly more worth your money than a stealth bomber (which i beat in a drag race hands down). As for mass production UNI is my priority and after engineering who knows what could come next .

 

[cribby546]

Final product...