Thanks for that picture. I finally got mine and took a closer look. The MCU is an STM8 and theres a TI 272c op-amp attached to it.
http://www.st.com/internet/mcu/product/215113.jsp
looks like I could use a versaloon board to program the chip using 4-pin SWIM (which might be what that...
Would anybody with one of these be so kind as to take a pic of the front-side of the logic board with the Atmel microcontroller(s)? I'm interested in reversing/reimplementing the firmware to make a poor man's CA for my spare-ebike that is not worthy of the genuine article. It'll be a few weeks...
I'm headed towards building a longjohn/bakfiets too after having motorized my xtracycle longtail (rode it for 5 years unmotorized). longjohns with tiny tank wheels and low-center loads beat wobbly longtails hands down. I have ridden an atlas, and the ride quality beats my average xtracycle, kona...
Ok, I think I've finally figured these old supplies out and have a way to get them to charge my packs.
(apologies for not filing this thread under the battery section in the first place)
The mains go into a step-down center-tapped transformer to get 24vac and the isolation needed for...
thanks guys. I did not read about columb counting in any of the charger+BMS designs I had looked through - the ones I saw monitored each cell and would shunt-resist current away from them once they approached HVC, and then kill-signal the charger once all cells were being shunted.
I think...
well shoot, I misread that label, I thought it said CVCC, not CVDC...now I have a boat anchor. I'm not sure how much the current will sag as it reaches voltage, but that defeats the whole purpose of building a monster like this.
They came from Davis Salvage.
Preface:
Last week I salvaged a Chinese AOWA 36V pedal-elec. After stripping off the cheezy plastic panelling, I found a very solid bike that was fun to "drive" (the cranks are just above the ground and are 155mm long with a 1:1 gear ratio, making "riding" a bit of a joke) but the SLA batteries...
I found this little blurb today about using an inkjet printer to lay masks directly to copperclad board so you can etch your own prototype PCBs
http://www.instructables.com/id/Converting-an-Inkjet-Printer-to-Print-PCBs/?ALLSTEPS
the v4.5 BMS has a hell load of through-hole drillings that one...
Ah, durr durr. Thanks oatnet. I knew parallel cells self-balance, but I thought measuring across a single battery's leads would get an isolated reading (path of least resistance?).
so I'm looking at how the packs are wired with 1 balance wire for each string of 3 parallel cells, with the corresponding circuity on the BMS boards. It makes me wonder how a pack can be considered "balanced" when the cells are only monitored in strings rather than individually. Did A123 measure...
I found this thesis while I was looking for information on building a BMS/charger. I couldn't find any prior reference to it already on the forum, so here it is:
The Development of an Electric Tricycle and Buck-Topology-Based Battery Pack Charger - Matthew John Taschner
Its nice to have a build...
I ordered 3 7s3p's and just got them today. took about 5 days from Shenzen to Phoenix. the delivery man missed me at my house, so I went to the airport depot and picked em up myself.
The box was 4 pieces of warped 5-ply and tack nails. had i not picked up the pack, it would have probably...
I got one of these hubs bare to complete a sh*ts-n-giggles spare parts build. the axle is threaded with two different, but equally infuriating and inappropriate pitches, so DONT LOSE THE OEM NUTS
left side: 9/16-20 RH (only used for bicycle pedal axles & cranks!)
right/drive-side: 7/16-28 (only...