Search found 219 matches

by ChrisBarron
Sat Mar 08, 2014 4:14 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

I have assembled the balancer leads now and connected them all together on an interface board. This forum isn't allowing me to post any more photos, so here's a link to Flickr http://www.flickr.com/photos/28496053@N04/13011898075/ Now that all of the 'layers' within each of the 4 packs is connected ...
by ChrisBarron
Sat Mar 08, 2014 11:42 am
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

I left a 125a pack on around 4amps for a number of hours, and I guess that was just too much for the cell that was shorted. It was effectively taking down the cells in the parallel layer around it at a low rate but when a higher current was passed through it it just gave up and made a great heat so...
by ChrisBarron
Fri Mar 07, 2014 10:54 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

I have some fuses coming for the balancer leads, but not for each of the cells. Had to refresh my knowledge regarding failure current and breaking current. I've selected devices suitable for 300A breaking current and 10A failure. The cell which 'exploded' due to a screw being misguided when I fixed ...
by ChrisBarron
Wed Mar 05, 2014 9:36 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

fakes always appear. I remember reading of an imported EV from china that reportedly had several sets of batteries fail - so the purchaser decided to chop open a battery and found that half of the lead plates were missing and there was sand in the bottom to make up the weight !!!! They probably con...
by ChrisBarron
Wed Mar 05, 2014 12:50 am
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

Really ? :lol: He hated my battery monitor design, when I requested ideas for an acronym for it he suggested 'B.O.M.B', because as far as he was concerned all battery fires had begun with a BMS. But he wasn't prepared to distinguish between a voltage monitor and a balancer at that time. I'm going to...
by ChrisBarron
Tue Mar 04, 2014 9:25 am
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

I just caught up with Jehu Garcia's episode 25, where he got a real world test of his 18650 battery. http://www.youtube.com/watch?v=EO04IynWNAg (detail starts at about 10 minutes) Very encouraging. He has 150 cells in parallel, I have 84 in parallel. My system voltage is much lower than his but my b...
by ChrisBarron
Sun Mar 02, 2014 7:40 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

Just waiting for a few more microcontrollers to arrive and I'll have the full pack voltage monitoring system built and ready to spit out data to a suitable host interface with a display. I've made up the harnesses that will connect all pack submodules together toa remote junction box. This will have...
by ChrisBarron
Tue Feb 25, 2014 6:43 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

Yes there is a natural balancing within each submodule of 21 cells. I hadn't considered the idea of paralleling each submodule with the equivalent module in another finished battery pack. I suppose that could work quite well actually ! Four 21-cell modules in parallel equates to 84 parallel cells. I...
by ChrisBarron
Thu Feb 20, 2014 2:45 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

I've had a contact from a battery company in the far east, if anyone is interested. They can weld tabs to each cell for a further $0.35 per per cell Good day to you!How about you? This is betty from Brillipower.We are so glad to know you from the Internet. We are a professional factory manufacturing...
by ChrisBarron
Wed Feb 19, 2014 10:07 pm
Forum: Electric Motor Bikes
Topic: Another EV bike :)
Replies: 135
Views: 179963

Re: Another EV bike :)

17 days later....and the four packs are complete ! :D Only one is fully charged and balanced, but it will be enough to start playing about for now. I'm working out a scheme for a balancer system based on the 'flying capacitor' method, where the cell with the highest voltage charges a capacitor, whic...

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