jerrysimon wrote:Hi as I have said these look pretty neat and I have expressed interest in a PM. I just wanted to clarify how this may have prevented my recent loss of two cells.
As explained in my main post in the battery forum I lost two cells one in each of a 2 * 6s1p pack in succession over a three week peiod. The pack was two years old and had done 500 charge cycles.
I am wondering how this unit might have avoided that given that when I measured the pack at rest 11 cells were around 3.2v and one had dropped down to below 1v ?
If it is recommened that the LCV is set to 2.75v/cell i.e. 33v for a 12s1p the pack then the above failure would still have happened as the pack would have been at 37v, or, am I missing the fact that it was at rest when I measured it and when actually using it the voltage sag would take the pack down to less than 33v ?
Ps I just found the real time (during the ride) Cell Log data I took when the pack failed and on the failing 6s1p pack, five of the six cells were at 3.15 when the bad cell went down to 2.0v i.e. this 6s1p pack voltage was 17.75v. If the other 6s1p pack was around 3.15v/cell (the all good cells would probably have been higher) i.e. 18.9v for the pack then the total 12s1p pack would be around 36.65v. So does that mean for 12s1p, A123 packs that the LVC should be set at 36-37v not 33v ?
In my case if it was set at 33v for the whole pack then its unlikely having the the Smart Switch V4 fitted would have prevented me losing the cell.
jerrysimon wrote:... Pocket open showing unbilical from from the bike to the bag.
teklektik wrote:jerrysimon wrote:... Pocket open showing unbilical from from the bike to the bag.
JS- interesting connector pair - can you afford some details?
lock22 wrote:Hi kfong
been catching up on lots of threads, and your switch looks like the business for everyday use. I currently have a 48v lifepo4 system on a cyclone kit, as you, and am using the goodrum/fechter bmc, am happy with this apart from 2 areas, size and battery deconnexion. Your design answers both these questions but I do have a 3rd; being a mac user, the windows prog is going to cause a bit of bother. Any simple solution you may have is welcome, or I suppose I can borrow a pc if necessary?
and are your boards still available?