DIY Electric Car Forums banner

1 - 1 of 1 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
So tonight after a 5 mile drive in the Prizm

Statistics on car and pack are:
300 volt pack
Pack is 2 years old, has 6 new batteries spread through the pack.
Two strings of 26ah UB12-260's in parallel
Two strings of Paktrakrs (black and white)
Lee zener regs on every battery with CM43 bulbs, 6.2/6.8 zeners,
10 ohm .5w metal film resistors)

Charger is Dolphin on-board, 2.5a to 370 volts, then 2.0 to 383 then
constant voltage between 362 and 370.

I decided to run a full and serious equalize on the pack. Taking all
batteries to full.

Checking at finish charge (373 volts on E-meter) On the black string,
all batteries read at 14.7 or above (15.1 tops) with the exception of E6
which read 10.0 volts.

Hm, that would be bad. Except when I cross-check the pack voltage to the
E-meter I see 368.3 versus 373 on the E-meter. The diff would put that
battery at 14.7 volts, which makes more sense.

Lesson 1: Paktrakrs can lie.

Cross-check, I connected to Paktrakr string white. It read 373.8 while
the e-meter read 373. Probably more accurate.

String white looks to all be at 14.7-15 volts with the exception of
battery C4 which only read 13.8 volts. Once again, a tiny bit odd there.
I should watch C4 under drive conditions and see what's up.

All in all I think my first run was an insane set of Paktrakrs. I doubt
that batteries would go to 3 volts, then run happily the next day. Odd.

Temps in the box are *high* with full regs. In the tunnel with the
Paktrakrs in the center I see the following:
Sensor Black White
A 73 89
B 106 135
C 122 124
D 126 131
E 80 122

Note that these are the temps *above* the batteries and in the case of
B,C,D the unit is right over either a lamp or a reg lug. So they are
reading somewhat high. However no question, the regs are putting out
some heat. Glad it's getting cooler.

A quick check on two sensors embedded *between* the batteries shows a
temp-between-two-batteries in an enclosed space to be 80 degrees. So the
batteries themselves are not as hot as the space above.

Overall we'll see. I'll keep an eye on white-C4 to see what's going on
there. And I'll take the driving numbers with a tad of salt, it's
possible that electronic interference is screwing with the numbers. The
cross-check there is to check against the E-meter, if the PT total pack
voltages are skewed from the E-meter then something is up.

Once again, never dull.
Chris

_______________________________________________
| REPLYING: address your message to [email protected] only.
| Multiple-address or CCed messages may be rejected.
| UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
| OTHER HELP: http://evdl.org/help/
| OPTIONS: http://lists.sjsu.edu/mailman/listinfo/ev
 
1 - 1 of 1 Posts
Top