Steve Powers wrote:
Bruce hit the home run with his answer. I am trying to save my pack from premature death (once I install a new pack; the current pack is only worth core value). I plan to get a small rugged PC and monitor the pack in use (driving) and charging. The best bet is probably to use a DMM with serial port hooked to a PC. Then, I can get all the data I want. I can measure voltage and current with time. I can calculate AH in, AH used in driving, etc. This is the best solution and the one that is easiest for me with my skill set. I will also integrate a small relay box to control various things, one of them being the charger shutoff.
This is a workable plan. It's what I did with my earlier rev.A Battery Balancer (see http://www3.telus.net/nook/balancerland/balancer/index.htm). Multimeter with isolated serial output. Relays to switch its input between volts and amps, and to any desired battery. Since PCs are poor at I/O, I used a BASIC Stamp to run the relays, and read and format the multimeter data before sending it to the PC. Make a little "battle language" so the PC can send commands (turn these relays on, send me the voltage, etc.) The PC can also be left off or disconnected, while the BASIC Stamp continues doing what it was last told to do.
-- A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering. -- Freeman Dyson -- Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
