Search found 859 matches

by GregsGarage
Wed Apr 10, 2013 9:04 pm
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

3D printing looks fun and great for one-offs, but I am looking for quick assembly. So here's the plan. http://img703.imageshack.us/img703/5690/imag0033yb.jpg The board sits inside the case. I am getting some prices to have new end panels laser cut from a sheet of clear perspex. One A4 size sheet giv...
by GregsGarage
Mon Apr 01, 2013 10:32 pm
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

I couldn't decide on a case for the pcb so I chose 3. :shock: Here's a board outline that will fit several cases.

Image

I'm going to get some prices and check lead times.
by GregsGarage
Sun Mar 31, 2013 10:05 pm
Forum: All things battery related
Topic: HELP - designing BMS for HEV using 40Ah batteries
Replies: 4
Views: 8445

Re: HELP - designing BMS for HEV using 40Ah batteries

As Peter says;

retepsnikrep wrote:All the info you need is in these BMS threads.
Give yourself a week to read a major chunk of it. Then ask relevant questions in the specific threads.

Peter
by GregsGarage
Sun Mar 31, 2013 9:38 pm
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

Looks like a nice project. :D By keeping the slave modules separate from the master means you are free to use whatever communications protocol you like (bluetooth, CAN, RS485, etc.). Just design it into your master or incorporate it into your existing controller. Another advantage of keeping the sla...
by GregsGarage
Sun Mar 24, 2013 10:53 pm
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

http://img829.imageshack.us/img829/3771/68022slvside.jpg PCB layout nearly done, just need to carefully check for errors and I want to add some mounting holes. Size of the pcb is approx 50mm x 80mm. Just need to settle on a suitable enclosure for it. More images on github along with the kicad files.
by GregsGarage
Thu Mar 14, 2013 9:07 pm
Forum: BMS thread
Topic: Maximite Master
Replies: 39
Views: 50191

Re: Maximite Master

I've done a video tour of the bms, at about 1:45 you see the screen refresh rate as I blip the throttle a couple of times. http://www.youtube.com/watch?v=92ZabILEuZg I've been trying to come up with a naming convention for both versions of the bms. I am thinking Generation 1 for systems with pic bas...
by GregsGarage
Wed Mar 13, 2013 10:19 pm
Forum: BMS thread
Topic: Maximite Master
Replies: 39
Views: 50191

Re: Maximite Master

Some more work on the master code. Pressing the left or right arrows allows you to highlight a cell in the bar graph and display it's voltage. Scrolling all the way to either end turns off the selection. The "12.7" is amps display (car was on charge when the screen shot taken), a bit rough...
by GregsGarage
Sat Mar 09, 2013 6:06 pm
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

Slave code is finished! :shock: Well not really, :lol: but it is at a level that all the basic functions work. The slaves can report cell voltage, temperature and current to the master. 8) A list of the slave commands are below. ' Command $01 (WRCFG) = Write configuration register group ' Command $0...
by GregsGarage
Fri Mar 08, 2013 9:06 pm
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

I've changed direction slightly, instead of getting the slave to calculate current I am sending the raw adc value to the master and converting it into amps there. Several advantages to this approach. Speeds up slave software development and doesn't tie the slave to only working with a particular sen...
by GregsGarage
Thu Mar 07, 2013 10:24 am
Forum: BMS thread
Topic: LTC6802 based 12 cell slave.
Replies: 75
Views: 82542

Re: LTC6802 based 12 cell slave.

:D :D :D I've just managed to connect my allegro current sensor to slave 1 and it works! :D :D :D I am plugging it onto the ICSP header. The code is very crude at the moment, basically just copied and pasted Peter's current sensor routines from master V2 into the slave. The CheckCurrent routine runs...

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