My first ebike battery build, 12p10s for A2B Metro

[grifftek]

After lurking here for well over a year now I have built my first e-bike battery pack.

The pack is made up of 120 Sony 18650 G5 2200 mAh cells in a 12p10s arrangement.

There are many more pictures of my battery build here, please check it out: http://tinyurl.com/4mzz5jm
You can also see my other a2b metro projects (cruise control, cadence magnet holder, chain guide etc) at http://tinyurl.com/4bnz6kq

the bike is a well used a2b metro I purchased from a member here a few weeks ago that had a dead batery.

I modeled up the batteries in solidworks and then designed a box around 2 bricks of batteries with a space inbetween for a bms. I wanted this to be nice and strong to protect the cells in case of a crash so the box was designed to have 1/2" wall thickness and was prduced in a SLS 3d printer from nylon powder laser sintered. The box is very robust and you could probalby drive a car over it without any damage.

Here is a shot of the 2 bricks of cells:

I used a battery protection circuit from tenergy. It seems to charge the pack and balance the cells just fine, but when you connect the load to the bms, it shuts down. I am working with Them to resolve the issue right now. Hopefully this process will go smoothly and they either fix or replace my board. In the mean time I have ordered another bms from Hightekbikes. hopefully it will be here tomorrow. Im anxious to do some riding to see how well it performs compared to a stock battery.

Here you can see the box, batteries wrapped in foam and squezed into the box and the BMS installeda nd wired

I had to make a slide system to mount the battery to that would adapt to the metros auxillary battery mount. I wlll design another sls box that slides onto the bike directly when I get the time.

There are many more pictures of my battery build here, please check it out: http://tinyurl.com/4mzz5jm
You can also see my other a2b metro projects (cruise control, cadence magnet holder, chain guide etc) at http://tinyurl.com/4bnz6kq

Regards

Bill Griffin
grifftek at live dot com

 

[dogman dan]

First class work dude. 8) But is it a wheeliemobile now? Looks big, but I don't know what it weighs. I guess it's OK if under 15 pounds.

 

[spinningmagnets]

outSTANDing work! I love the CNC desktop motorcycle, and the shop looks VERY professional. Some of the parts appear to be CNC aluminum, but others may be some form of strong plastic? Did the cells come tabbed (if yes from who?) or did you spot-weld them yourself? and who assembled the pack?

I think there is a real market for two panniers of similar construction, especially if the batteries were in the bottoms, and the top halves allowed a small amount of cargo room for gloves, cable/lock, etc. Is there any chance you might make a few battery boxes for sale in the future?

Would you be interested in modeling a triangle box that is solid on the left and has a hinged lid on the right that opens like a trucks tailgate? There are different sizes of frame triangles, so it would need to be as small as possible to fit a variety of them.

edit: Since you have done the research for cell arrangement, I am hoping it would be fast and easy for you to provide some general dimesions for a 48V pack (as many Ah as possible). You seem to be the kind of guy who has done some in-depth homework, what made you choose those type of cells?

 

[grifftek]

First class work dude. 8) But is it a wheeliemobile now? Looks big, but I don't know what it weighs. I guess it's OK if under 15 pounds.

Well, its far from a wheelie mobile, especially with my big carcass on it LOL!
Its approximately 13" long 8.85" wide and just less than 4" thick. Ill get a picture of it next to a metro with the factory B battery option installed. Honestly its not that bad especailly considering its 2 1/2 times the capacity of the factory battery.
Im not sure of the weight either, but I know its not under 15 lbs for sure. just the nylon enclosure is heavy looks like about 11 lbs just for the enclosure:

This is the mass properties for the main housing:
Mass properties of batbox_temp-1 ( Part Configuration - Default )

Output coordinate System: -- default --

Density = 0.0506 pounds per cubic inch

Mass = 7.9557 pounds

Volume = 157.2960 cubic inches

Surface area = 658.7634 inches^2

Center of mass: ( inches )
X = 4.4222
Y = -6.5263
Z = 1.3680


Mass properties of the lid:
Mass properties of batbox_lid_temp-1 ( Part Configuration - Default )

Output coordinate System: -- default --

Density = 0.0506 pounds per cubic inch

Mass = 2.9860 poundsVolume = 59.0382 cubic inches

Surface area = 272.0110 inches^2

Center of mass: ( inches )
X = 4.4250
Y = -6.5313
Z = 0.2645

bill

 

[grifftek]

outSTANDing work! I love the CNC desktop motorcycle, and the shop looks VERY professional. Some of the parts appear to be CNC aluminum, but others may be some form of strong plastic? Did the cells come tabbed (if yes from who?) or did you spot-weld them yourself? and who assembled the pack?

I think there is a real market for two panniers of similar construction, especially if the batteries were in the bottoms, and the top halves allowed a small amount of cargo room for gloves, cable/lock, etc. Is there any chance you might make a few battery boxes for sale in the future?

Would you be interested in modeling a triangle box that is solid on the left and has a hinged lid on the right that opens like a laptop computer?

The stainless steel motorcycle was given to me and came from a sheetmetal vender as a christmas gift. It was originally a business card holder, I ripped it off its base and just leave it on my desk. As soon as my son coms to the office, it will be gone (just like last years gift) that I cannot remember!

I agree with the panier idea and it woudl be much easier also. My metro has paniers on it:

make a rigid enclosure for a pile of lipo batteries that fit in the bottoms of the panier bags and simply insert them in the panier bags. then you still have the rest of the space in the bags for whatever. As long as the bags and mounts are sturdy enough to handle the weight it shoudl work nicely and get the CG down low.

ill pm you concerning the cad work

Bill

 

[dogman dan]

As long as it handles ok then it's cool. I just wondered. Cool that the A2B can carry a bit more weight there.

I have carried lots of battery in the rear, and some bikes it works fine, some not. You know when you have too much, the frame starts flexing and you feel that front wheel skittering with poor traction. I got one really wrong once, and you could barely keep the front wheel on the ground at all.

 

[Ypedal]

Hey !!.. Great to see you posting !

That B battery is looking slick, i like it..

Dogman, the A2B is front end heavy and the frame is very ridgid, the rear shock needs replacing but it's a good solid bike, i wish the front fork had a bit more rake but it's not critical..

How cool is this !!!

 

[grifftek]

For comparison sakes you can see two bikes side by side, one with the factory B battery and the one I made:
http://tinyurl.com/6lfzrz3

Bill

 

[E-racer]

Is that a 3d printed dash as well? I love your work. We have a dimension 3d printer at school but the cartridge costs are RIDICULOUS. I have printed a few similar parts for our Formula SAE car.

 

[grifftek]

Is that a 3d printed dash as well? I love your work. We have a dimension 3d printer at school but the cartridge costs are RIDICULOUS. I have printed a few similar parts for our Formula SAE car.

That is a bag my son puts his itouch in. I don't have. Any instrumentation for a dash yet.

I know the costs are crazy still sls is alot more expensive than fdm over 14k per 100kilos not to mention mach cost maint and. Operating costs

Bill

 

[E-racer]

I assume so. Im so close to building a rep rap for at home usage. The lack of support material makes me a little nervous though.

 

[grifftek]

I assume so. Im so close to building a rep rap for at home usage. The lack of support material makes me a little nervous though.

I heard from our service tech that 3d systems bought out one of the DIY fdm companies and is offering their system for sale. He told me that you have to assemble it yourself. I havent verified this. I had seen a rep pap type machine that had up to 4 heads so you could print in 3 colors and have support material. Without support material you will have serious problems building any model with overhangs.

I bookmarked the system I seen onone of my computers, Ill try to find it and post it here.
I was toying with the idea of building one and salvaging the unused materials from our fdm canisters. there is always dozens of yards of material left in the canister when the machine says its empty.

Bill

 

[grifftek]

BMS Success!

After having a problem with the BMS from Tenergy and not being able to resolve the issue after 2 weeks then being told that I needed to send the old board back first before they could issue a replacement I gave up on them and just asked for a refund. we will see if they come through on that!

I ended up buying a signalab BMS from Terry at Hightekbikes. The signallab is not as powerful as the tenergy unit, but at least it works! Its more than capable of dealing with the current requirements of the A2B in stock form at least.

I wired it up to my pack using molex minifit jr connectors. I also installed a cell voltage measurement connector isolated with 1K ohm resistors o allow me to measure each parallel cell pack voltage without taking anything apart.

Using a powersupply I charged the pack for the first time with the signalab and it turned on all of the lights within 20 minutes of charging. I then went for a 3 mile ride (at 4am) to bring the charge down a little and then charged the pack using the stock a2b charger. I measured the cell voltages using my cheap meter at home and all the individual voltages were within 0.01 volts with 4.19being the average reading. Now where did I put my fluke 77? I gotta get a real meter to get some better resolution!

I have 2 a2b chargers, one has a higher voltage output. I need to try and find out which pot to adjust (there are 5 or 6 of them inside) to get the chargers matched closer. Anyone know what pot does what in the a2b charger? Ill try and get the model number of the charger. and post it later.

Bill

 

[odotan]

I am planning on buying an A2B Hybrid on ebay, but I will need a charger for Europe (230V).

1. Does anybody know whether the charger that comes with the bike is a universal charger or if it needs a specific voltage (110/220/230/240V)?

2. If I wish to use a voltage converter (such as here: http://www.voltagevalet.com/prod_vc_hdt.html ) and use the original 110V charger, what is the power output (how many watts 100W, 200W, 500W?) that the converter needs to provide?

I am talking about whether I would need something like this (300W):
http://www.voltagevalet.com/prod_vc_hdt/TGC300.html

or something like this (500W):
http://www.voltagevalet.com/prod_vc_hdt/TGC500.html

Thanks in advance for any advice

 

[Ypedal]

the " Hi-Power " brand charger that came with my A2B has a selection switch for both 110 and 220. 8)

 

[odotan]

the " Hi-Power " brand charger that came with my A2B has a selection switch for both 110 and 220. 8)

Thanks! That's good news. Could you please tell me the specs on the charger (input, output etc). A picture of the label with this info would be great!

Thanks a lot again

 

[Ypedal]

http://ypedal.com/A2B/index.htm

 

[odotan]

Thanks a lot! that's a great review.

I have finally received my lovely A2B, and I am completely in love with it (can humans fall in love with inanimate objects?!)

Anyway, I was wondering if there's a way to disable the (electronic) speed limit of 15.5 mph/25kmh. The motor stops assisting at around that speed, but it's obvious it still has power to go faster.

Would I have to replace any components inside the bike, or is there a way to modify the existing parts/electronics?

Thanks again

http://ypedal.com/A2B/index.htm

 

[999zip999]

i know on the chiense bikes have a euro speed wire that you unplug to go over 15mph.

 

[odotan]

i know on the chiense bikes have a euro speed wire that you unplug to go over 15mph.

I have the european bike (it came with a european charger and a "CE" sticker on the motor).

Where would I find this "euro speed wire"?

 

[qazzy1]

that's it .. it goes like 50mph fresh battery for a second but consistently 35+mph .. lyen mark2 infion .. crystalite 40ty something .. stock batteries in series..

 

[tonyinvent]

Very nice,
Can you tell me what the name of the original connectors from the bike to the battery are called.
Did you use same female connector on your battery ?
Many thanks,
tonyinvent

 

[Hillhater]

Can you tell me what the name of the original connectors from the bike to the battery are called....

If you mean those neat 6 pin plug and screw yellow connectors,...i would call them "unique" and impossible to source !.
There is a thread somewhere with the makers name and part number (European), but I have tried every online source and numerous Ebike /A2B specialists with no luck..
Only possibility is to locate someone dismantling an old bike.....unlikely !