My truck has been acting weirdly. Voltage sagging way
more than it should. Usualy the voltage would return
almsot instantly when letting off the accelerator, but
last night, with only about 15 amp-hours out of the
pack, I noticed it was taking 10s of seconds to
recover. This is not good... As soon as I got home, I
checked each voltage, but by that time the pack
voltage had returned pretty much to normal. I fixed
my heater (bad ground on the relay that controls the
contactor to the heater), turned on headlamps, power
steering, fan full blast, and heater on high, and
while drawing about 15 amps off the pack, checked
voltages again, but still all pretty close to each
other. Darn... so I bumped up the voltage a bit on
the PFC-30 and started charging, planning on wattering
after a full charge. Near the end of charge, I was
inspired to check voltages again, and most were at
about 8.1V (a bit high), 6 batteries, interestingly
enough, all in the same battery box, and they were the
dirtiest of them all (maybe significantly higher
leakage currents discharging them? Hard to imagine it
could be significant...) were reading more like 7.5V.
So I'm goiing to try to indiviually charge these 6
T125s.
I've got a 7.5V, 70A adjustable voltage/current power
supply, that I think goes up a bit higher in voltage.
If so, I'll equalize each of those 6 batteries
individually. If not, I've got some other options,
like a 50V 20A sorensen power supply. Another option
might be, bring down the entire pack, use the 7.5V
power supply to bring up these 6 batteries as much as
possible, then charge the entire pack.
I was not able to find much in the way of technical
information on the Trojan web site. What little I did
find was a chart that says to equalize at 7.8V per 6V
battery, adding 0.028 volts per cell for every 10 deg.
F below 80 deg. F (It was about 70 deg. F last night).
So I plan on charging at about 7.9V (assuming it's 70
degs again) until the current tapers to about 4 amps
so so. Is this the correct way to do it? I imagine
it would be "best" to keep charging until the specific
gravity of each cell is the same, but for some reason,
I'm not very good at getting consistant results from
my (temperature compensated) refractometer. I'll try
taking readings, at least before, middle and after,
but I can't really count on being able to do this
often enough. Someday I'd like to try rigging a
digital camera, or small b&w video camera to this
thing, so I don't have to squint as much, and
hopefully can get more consistant readings.
Does the above sound good? Any other suggestions?
Thanks for your time,
Steven Ciciora
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_______________________________________________
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more than it should. Usualy the voltage would return
almsot instantly when letting off the accelerator, but
last night, with only about 15 amp-hours out of the
pack, I noticed it was taking 10s of seconds to
recover. This is not good... As soon as I got home, I
checked each voltage, but by that time the pack
voltage had returned pretty much to normal. I fixed
my heater (bad ground on the relay that controls the
contactor to the heater), turned on headlamps, power
steering, fan full blast, and heater on high, and
while drawing about 15 amps off the pack, checked
voltages again, but still all pretty close to each
other. Darn... so I bumped up the voltage a bit on
the PFC-30 and started charging, planning on wattering
after a full charge. Near the end of charge, I was
inspired to check voltages again, and most were at
about 8.1V (a bit high), 6 batteries, interestingly
enough, all in the same battery box, and they were the
dirtiest of them all (maybe significantly higher
leakage currents discharging them? Hard to imagine it
could be significant...) were reading more like 7.5V.
So I'm goiing to try to indiviually charge these 6
T125s.
I've got a 7.5V, 70A adjustable voltage/current power
supply, that I think goes up a bit higher in voltage.
If so, I'll equalize each of those 6 batteries
individually. If not, I've got some other options,
like a 50V 20A sorensen power supply. Another option
might be, bring down the entire pack, use the 7.5V
power supply to bring up these 6 batteries as much as
possible, then charge the entire pack.
I was not able to find much in the way of technical
information on the Trojan web site. What little I did
find was a chart that says to equalize at 7.8V per 6V
battery, adding 0.028 volts per cell for every 10 deg.
F below 80 deg. F (It was about 70 deg. F last night).
So I plan on charging at about 7.9V (assuming it's 70
degs again) until the current tapers to about 4 amps
so so. Is this the correct way to do it? I imagine
it would be "best" to keep charging until the specific
gravity of each cell is the same, but for some reason,
I'm not very good at getting consistant results from
my (temperature compensated) refractometer. I'll try
taking readings, at least before, middle and after,
but I can't really count on being able to do this
often enough. Someday I'd like to try rigging a
digital camera, or small b&w video camera to this
thing, so I don't have to squint as much, and
hopefully can get more consistant readings.
Does the above sound good? Any other suggestions?
Thanks for your time,
Steven Ciciora
____________________________________________________________________________________Ready for the edge of your seat?
Check out tonight's top picks on Yahoo! TV.
http://tv.yahoo.com/
_______________________________________________
For subscription options, see
http://lists.sjsu.edu/mailman/listinfo/ev