Hi Folk's,
On my www.evalbum.com/2749 E-Cat I noticed after two boating seasons (about 50 cycles last year and another 50 this year) that battery (buddy pair cell) number 15 out of 16 wasn't coming up to the 3.8V clamp voltage, stuck at 3.4V with the final 1 amp charge taper. I put a 8 amp individual charger across that one for an hour and that propped it up. I'm not sure why one cell would drift low when they're all clamped (with shunt balancers) to 3.8V on the final two hours of charge dv/dt=0 stop.
Also I've been using the same charger algorthm on floodees, STM5-180's Ni-Cads (40k miles - 1300 cycles), NiMH batteries and now LiFePO4 Thundersky 3.3V 200ah (actually 100ah buddy pairs). The algorithm recommended previously by Trojan's Jim Drizos for a GE charger patent 6,218,812 I did simply looks at each hour and compares one hour to the next and when the voltage is < than .01V per cell per hour rise (the voltage stops rising or may fall slightly on NiMH) the charger stops. It's served me well over the years, no fancy temp compensation and seams to work well for all battery types.
BTW, on www.evalbum.com/1273 last night my auxilary 12V motorcycle 12AA battery had dendrites across the plates (stuck at 11V) I tried charging with an 8amp charger but it got hot, 120F so replaced and noticed a ghost load of 11ma from the radio (which killed it while sitting in the garage over time - been driving my 70mpg Honda Insight to night windpower teaching classes at www.dslcc.edu). So I pulled the radio and the ghost load dropped to 1.6ma, pulled all the fuses, still there, probably back-feed into dc-dc conv. Do folk's put a switch on the aux battery to elliminate ghost loads while parked for awhile? Or leave the dc-dc converter on, probably reliability converter problems though? Maybe a 13.8V trickle charger plugged in all the time?
Have a renewable energy day,
Mark
www.reevadiy.org solar home tour tomorrow Oct 9th www.nationalsolartour.org my place EV rides
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On my www.evalbum.com/2749 E-Cat I noticed after two boating seasons (about 50 cycles last year and another 50 this year) that battery (buddy pair cell) number 15 out of 16 wasn't coming up to the 3.8V clamp voltage, stuck at 3.4V with the final 1 amp charge taper. I put a 8 amp individual charger across that one for an hour and that propped it up. I'm not sure why one cell would drift low when they're all clamped (with shunt balancers) to 3.8V on the final two hours of charge dv/dt=0 stop.
Also I've been using the same charger algorthm on floodees, STM5-180's Ni-Cads (40k miles - 1300 cycles), NiMH batteries and now LiFePO4 Thundersky 3.3V 200ah (actually 100ah buddy pairs). The algorithm recommended previously by Trojan's Jim Drizos for a GE charger patent 6,218,812 I did simply looks at each hour and compares one hour to the next and when the voltage is < than .01V per cell per hour rise (the voltage stops rising or may fall slightly on NiMH) the charger stops. It's served me well over the years, no fancy temp compensation and seams to work well for all battery types.
BTW, on www.evalbum.com/1273 last night my auxilary 12V motorcycle 12AA battery had dendrites across the plates (stuck at 11V) I tried charging with an 8amp charger but it got hot, 120F so replaced and noticed a ghost load of 11ma from the radio (which killed it while sitting in the garage over time - been driving my 70mpg Honda Insight to night windpower teaching classes at www.dslcc.edu). So I pulled the radio and the ghost load dropped to 1.6ma, pulled all the fuses, still there, probably back-feed into dc-dc conv. Do folk's put a switch on the aux battery to elliminate ghost loads while parked for awhile? Or leave the dc-dc converter on, probably reliability converter problems though? Maybe a 13.8V trickle charger plugged in all the time?
Have a renewable energy day,
Mark
www.reevadiy.org solar home tour tomorrow Oct 9th www.nationalsolartour.org my place EV rides
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