LocationPhoenix, Arizona United States map
Email email image
Vehicle1989 Toyota Corolla GTS
Got it used on Craig's list with a seized
motor - only $300!
MotorNetgain Impulse 9 Series Wound DC
ControllerOpen ReVolt Cougar
144V 500A model
This is the DIY controller created by Paul
Holmes - very impressive, works incredibly
Batteries45 CALB/Skyenergy CALB 180 AH, 3.30 Volt, Lithium Iron Phosphate
These lithium cells are amazing.
Picked them up from CALB's warehouse in LA
- they were great to deal with.

I tested 120V for a couple weeks and
decided to go for 144 since I had the
space for more batteries. The car is
heavy, but voltage sag and battery amps
are much less.
System Voltage144 Volts
Charger 144V 20A
My own design - charges at 10A from
110AC and 20A from 220AC, auto
detecting. It also receives info from
my BMS to reduce current if a cell goes
over the voltage threshold.

-OLD- (Quickcharge)
Seems to work well, just as the specs
say. It's big though, so I just have
it sitting in the garage as of now.
Currently developing a switch mode
charger on my own...
Heater2 Ceramic heaters in series. 144V
across one seemed to be too much and it'd
'pop' and only draw a few amps. The two
now draw around 10A total and create a
modest amount of heat, good enough for AZ.
DC/DC ConverterIota 45A
My Zivan blew when operating with a low
pack voltage after some lead batteries
went out. The Iota works really well
far. I added some extra fans to help
keep in cool in the heat. At some
I'll add a/c again and the extra fans
will increase the load on the Iota.

Zivan: Also works well. I forget the
but it brings the system up to 13.5V
pumps some amps into the accessory
battery to keep it charged. I haven't
seen the accessory battery drop below
12.2V (open circuit).
InstrumentationI ditched the paktrakr and built my own
BMS. It sends individual cell voltages
to a master LCD display where I can
display it the way I want to.
Eventually, I plan to have it talk to
the controller over serial cable - It
could display data from the controller
or command it to limit battery amps if
the pack is depleted.

Also added a Cycle Analyst. So far I'm
very impressed with its measurement

Paktrakr for battery amps and voltage

Digital Voltmeter for controller input
voltage - this will measure battery
volts once the contactor closes, but
when I turn on the breaker, I can see
the voltage rise slowly on the caps and
let it level off before starting to

Battery/Motor digital Ammeter - from a
50mv shunt in the motor loop and
in the battery loop. I have a relay
toggle switch to switch between the two
- I try to keep the amps low.

I also have a temp probe in the
controller heatsink since it'd be nice
to monitor in the AZ summers. The
Curtis I had didn't take kindly to the
heat and was often in thermal cutback
mode. The Revolt seems to handle it
really well with lower heat generation
and thermal mass. I'll see operating
temps in the 50's on hot days.
Top Speed70 MPH (112 KPH)
Added the '+' with the lithium cells.
pulls about 130A at 140V to cruise at
65mph now. Easily goes up to 70.

Pretty easily to 55-60 in 3rd. I put
into 4th once and got to 70 with room
spare, but didn't want to push it with
fairly new batteries.

AccelerationMuch better now that the lead is gone.
Weight is reduced by almost 900 lbs
with the new lithium cells, and that's
even with added capacity for more range.
Keeping up with traffic is not even
close to an issue now.

Enough to easily keep up with traffic.
The killer is waiting
4sec for the motor to spool down from
5.5k to 3k to shift from 1st to 2nd
(might put the clutch back in, or
develop a motor brake to spool down
quicker). Starting in 2nd is
possible, just slow out of the gate.
Range85 Miles (136 Kilometers)
I've maxed out the battery once by driving
around the block and drove a bit over 100
mi. Occasionally, I have driven about 90
mi with no issues. I think it's safe to
say I have an 80 mile practical range,
considering driving style, heat or a/c,

Not sure yet exactly. As of now, a 20mi
trip dropped the SG from 1.265 to 1.230
and a 44 mi trip dropped SG to 1.190 or
so, or about 55% SOC. My longest run
far has been 54 mi to about 50% SOC.
This is the typical trip out to the
school and back and luckily, it's
highway with only modest hills. Those
trips to the school and back would
at ~142V at 80A and end around 136V at
80A. Now, in the winter, I'm ending
around 131-133V at 80A, even though it
starts at the same voltage. I'm hoping
that's just temperature related.
Watt Hours/Mile250 Wh/Mile
Measured with a CycleAnalyst.

This is pretty typical for my style of
driving. Occasionally, I can get lucky
and average close to 230 wh/mi depending
on wind, traffic, temps, etc. Sometimes,
particularly when it's colder and the
transmission oil is thicker, it'll be
closer to 270 wh/mi. 270 wh/mi, or a bit
more, is also more typical with the heater
or a/c running.

my best round trip to date is a 52 mile
trip at 225 wh/mi during dense but
flowing traffic. I was able to
maintain 55-60 mph and draft behind the
EV Miles
Start:160,802 Miles (258,730 Kilometers)
Current:186,007 Miles (299,285 Kilometers)
Total:25,205 Miles (40,554 Kilometers)
Seating Capacity4 adults
Curb Weight2,850 Pounds (1,295 Kilograms)
Should be almost 900 lb less with Li,
maybe 2850 lb.

Weighed at the scrap yard. 2060 lbs on
the rear end, 3740 total.
TiresGoodyear Integrity, 185 70 14
I wanted B381's but couldn't justify
the high price to get 'em installed. The
GY's are the ones that come on the Prius
and, while an awful tire for poor weather,
are supposed to be pretty good for rolling
resistance. I have them inflated to 55
Conversion TimeGot the car at the end of May '08.

Driveable around town and to work in

Started the battery upgrade in Oct 2010
and finished in Sep 2011, along with a
lot of other small modifications.

Still a lot of work to do...
Conversion Cost~10k for Lithium cells
~400 in parts for charger
~400 in parts for BMS

300 for the donor car
2400 for golf car batteries
7000 for conversion parts
~1000 for tools (welder, drill press,
stuff I wanted anyway)

Labor: I'm guessing around 200 hours
Bought the car in May of 08 and began tearing it apart
that summer. Ordered parts in August and started putting
things together. I'd say most of the time was put into
testing and wiring the electronics to control the 12V
stuff and building battery racks. Got the car moving
around late November and finally road-worthy in Jan '09.

As of today, I have driven just over 100mi all EV with
around 10 cycles on the batteries. I just got the heater
working and was able to put the glove compartment
area under the dash back together. The driver's side
needs a lot of work still.

Plans to do:
Finish wiring various switches
Install Paktraker
Upgrade tires
Upgrade brakes
Fabricate/install grill dams
Fabricate/install engine compartment splash guards
Check for caliper rubbing
Wheel alignment
Replace rear speakers
Investigate homemade on-board charger

Have had the paktrakr working for a few days now. Works
well, but i'm having problems with recording the data
stream under high acceleration similar to others. I've
ordered several EMI suppressors, so we'll see how
that works.

At 60 mph, it appears to be pulling between 60 and 160
amps, depending on going uphill or downhill. at 100
the reserve capacity from the USB website is 80
minutes, which would equate to 40 miles to 50% SOC. I'm
almost there without doing any efficiency mods, so we'll
see what happens. It'd be impressive to get down to
75A for 115 mins of reserve capacity.

I did record a charge cycle though. The quickcharge
charger put out nearly 30A at first (good thing it's on a
30A breaker) and once it reached the cutoff voltage of
2.4v/cell, it held that for 3 hours. I did notice that
the current only dropped to 4A, and that was after only
min. I might try to proportionally timed gassing mode.

Also, just weighed it at the crap yard - came it at 3740
total, and 2060 on the rear end making the weight ratio
.81 to 1. Came in a little heavier than I expected, but
subtracting 1550 lbs of batteries, 150 lbs for the motor,
and about 100 for battery racks and cable, 1900 lbs is
about right for the glider.


Been monitoring the set of 4 new batteries that I added
bring the system up to 144V. They're a few cycles behind
the rest, so they discharge a little further than the
others and re-charge a little quicker. I'm hoping this
gets better with time, as a contact with USB suggested it

Another range data point: 20 mi trip to visit the
parents, consisting of 4 mi surface streets and 16 mi
highway (at 60mph, 55 up hills) brought SG down to ~1.225
on these newer cells. According to the charts, that's
around 70% SOC.

My solid state relay for controlling the heat element
failed, and of course it failed 'on'. I suspected it
might happen from what others have said, but it seemed to
be such an elegant option. Pretty bad to fail after only
a few cycles. Next option might be some sort of small
contactor, but it's pretty warm in PHX anyway.

Went to a parking lot and brought some equipment to
calculate rolling resistance. I wanted to see if I could
quantify the change when I upgraded to better tires.
These were the originals that I got the car with, but
pumped up to ~44psi (10 over the max). I used a mic to
record the audio as I coasted over a metal bar. From the
digital audio, I could get a decent time measurement, and
using the wheelbase of the car, I could calculate speed.
Then, by measuring the distance the car rolled, I could
calculate an acceleration (assuming it was constant) and
drag force, and ultimately
the coefficient of rolling friction. Anyway, it ended up
around .0103, which seemed right in line with typical
results. According to some testing I read, the B381's
at 0.006, 40% lower friction. I'll repeat the experiment
when I get a hold of a set and compare.

On another note, still haven't gotten the paktrakr to
record un-jumbled data.


I've spent most of the recent time working on a portable
switchmode charger. Currently, i've made a 'dumb'
that'll work up to 15 amps before getting too
hot. Once I get up to 25 amps, I'll work on making it

The longest trip so far was a 44 mi trip, mostly highway,
at 55mph up to Scottsdale and back. The trip brought the
batteries down to about 55% SOC based on SG
readings. I routinely make the 35 mi round trip to my
folks' place without issue. I haven't put it into prime
time for the 52 mi round trip down to the school and back
as i'd like to have a portable charger before venturing
too far.

I picked up a couple of sheets of coroplast for
splashguards and belly-pan for 20 buckas apiece, but it's
just sitting in the garage.

I got the controller heatsink thermometer working. Seems
that it operates about 15-20C above ambient. On a 95F
day, it did start to limit motor current to 375 amps for
a bit, but went back to normal after cruising a mile. Temp
reading was 45C.

I decided to go with Goodyear Integrity's for tires since
they were about half the price as the B381's... A lot of
reviews show that this is the OEM tire for the Prius and
users often complained of losing mileage when changing
tires. So far, I haven't noticed much of a change in
performance, though it appears that I'm cruising at the
same speeds with the same motor current. Presumably,
since the tires are a little larger, this means I'm
cruising about 5% faster for the same current draw

I put in a battery current shunt and a relay/toggle
to switch between motor current and battery current using
the same meter. Unfortunately, the shunts aren't exactly
the same (despite both being 500A 50mv shunts) and the
battery amps are reading about half the actual value (as
checked with my clamp meter). I'm going to work on a
opamp circuit to scale this reading up to the correct

I'll have to start working on some form of AC as it's
already getting pretty warm. I also keep putting off
upgrading the brakes. Conscious driving hasn't led to
any problems so far.


Not sure what the deal with the battery loop shunt was,
but now it's reading correctly. Maybe there was some
contact resistance in the wiring or connections somehow?
Anyway, it reads accurate to an amp when compared to my
clamp meter, so I'm happy. Biggest surprises so far:
keeping amps at or under 200 while accelerating is
actually pretty easy, and amps vary wildly with just a
small change in accelerator positioning. Once, I gunned
it to accelerate into the carpool lane and it peaked over
400A at around 116V - that's 46kw or about 62 HP!

Also, drove the furthest on a charge to date. 54 miles
round trip out to the school and back. The trip was
about 8 mi city driving with the rest of it highway.
battery amps at 55 mph were from 80-100 while I tried not
to exceed 150A up the modest hills. Cruising voltage
started at 141V and ended at 136 while resting voltage
started at ~153 and ended at 146. I didn't measure SG,
but based on how it's been behaving, I'd put this at a
little above 50% SOC. Temperature was about 90F, which is
cool for June, but nice for floodies.

I've also noticed that some of my terminals have been
getting warm, almost too hot to touch. I've heard about
EVer's lead posts melting, but lead's melting point is
about 600F! I don't think it's that bad, but I also
noticed that the few cable connectors that the battery
supplier made with O connectors were much cooler, only
barely warm. I concluded that this was because the OO
cable in a O connector was very tight and made a very
solid crimp and that the OO cable in OO connectors were
pretty weak using the hex crimper they have.

I picked up a hammer crimper a little while ago to make
some of my own cables, but hadn't used it yet. I took
one of the already-made cables in my battery string, removed
the heatshrink, whacked it in the hammer crimper, painted
some liquid tool handle coating stuff on it and
reinstalled. Voila! Ran very cool when compared to the
others! So, I'm slowly re-doing all of those original
hex crimps.

I picked up a seat cushion that has a fan to circulate
air through seat and back area. It's ok, but I'm still
scheming for some sort of AC.

Other current projects are the DIY charger and I'm
thinking about making an AH counter.


It's getting warm! I've concluded that the Curtis
controller tries to limit itself to operating around 50C.
Now that the ambient temp is 43C, I notice that it will
very quickly go into the 1.5khz mode to reduce the heat
losses. this tends to keep the operating temperature to
50C when cruising on the highway for a while. This temp
goes up when doing a lot of city driving and
- up to 53C so far.

So, that's only 10C above ambient, but it's in the lower
frequency mode A LOT! I can see when it switches modes
on the heatsink thermometer - it'll drop 1.5C degrees when
going from 15khz to 1.5 khz, and then go back up when it
goes back.

This explains how the heatsink temp could reach 50C when
it was still cool out - it wasn't going into thermal mode
yet. Now that it's hot, it just stays in the low
frequency thermal mode more often.

what's bad about the low frequency mode? first, you can
hear it, and second, I think it's pretty high stress on
the capacitors due to higher ripple current.

Nevertheless, i'm excited to soon be receiving the DIY
controller from Paul Holmes. It's the same specs as the
curtis, but has a lot less heat losses (on paper at
least). I hope it works well!

I'm also working on adapting a window A/C unit to use the
evaporator in the dashboard. so far though, I've only
picked up the A/C unit for 100 bucks at home depot.


Got the new controller! Woohoo! Works well and reliably
delivers power. I suspect things are ok as far as heat
dissipation, but things get pretty warm after a lot of
city driving or high amp freeway driving.

Bench tested the A/C and it worked! Perhaps not as great
as original, but temps down in the 50s with the fan on
high for about a 60 deg delta T. I've gotten all the
mechanical stuff installed less hoses, so once that's all
set just gotta work on the electrical stuff. I'm working
on an inverter to convert my high voltage DC to AC for
the compressor. If it works like expected, I should also be
able to control the speed of the compressor so i can just
turn it down instead of cycling it on and off.


I've been testing the DIY controller for a couple months
now and it's worked superbly. There's been a couple
glitches, but that's what beta testing is all about!
some software revision and some minor hardware additions,
I think its performance far exceeds the Curtis.

This is more so I can remind myself, but if you subtract
3000 from the total miles driven, that's about how many
miles are on the new controller.

The guys at AZ Auto and Air were awesome with assisting
me in my A/C endeavor. As of now, all the mechanical stuff
is installed and working - I just need to finish the
electrical part of it. It's not perfect, but I think it
will do the job.

As far as range is concerned, I've driven out to the
track and back many times now without issue. Recently, I did
notice that the voltage under load is much lower than
previous. Towards the end of drive, it's down to 132V at
80A rather than 136 or so. Two things I think contribute
to this: It's a lot cooler now than when I first
started making the drive - averaging 70F vs 95F, and I had
watered the batteries, so the electrolyte was more
dilute. I think those initial range tests were when the
were about ready to be watered, so it was more concentrated.


I had a battery that died a couple days ago. I had my
eye on this battery for a while now - it was leaking acid out
the top at first (caused a mess of the battery rack) and
a month or so ago, I noticed that the SG in one of the
cells was 50pts lower or so. I equalized it separately, but
that didn't help. I though some just leaked out, so I
thought about adding acid at some point.

But, before I could do that, I was about 3/4 of the way
through my commute and the paktrakr was showing only
about 2V under load while the others were almost at 6. I
stopped and bypassed it and noticed it was really warm.
It was just past the year warranty, but the battery shop
sold me a new replacement for $25, so I can't really
complain. It's all back together now, and running well.

I also tested my AC compressor inverter/controller and it
works well! I just need to fix a glitch in the software,
maybe add a boost regulator circuit, and install it in
the car.


updated the mileage; just about 6k miles all electric.
Actually, the new tires are an inch larger, so mileage is
low by about 5%. so, maybe it's closer to 6300 miles or

I haven't been driving much in the lower temperatures. I
notice that the batteries don't give as much range. With
highs in the 80's, i notice the voltage drops to about
134V at 80amps at the end of the commute, while highs in
the 60's drops the voltage to 131V. 126V at 75A would be
completely dead. I'm not there yet, but voltage is
dropping pretty fast at this point. I'm hoping this is
mostly just due to the temperature effect and less due to
the aging pack. time will tell as it gets warmer...

4-12-10 168030 miles, 7228 miles electric

I can already tell that the batteries are enjoying the
warmer weather. Voltage at 80A at the end of my long
commute is back up to about 135V or so with the 80F
weather. I think the warmer weather also greatly affects
the viscous drag in the transmission. Before, the car
seemed sluggish early in the mornings and required more
amps than normal. Once everything warmed up after a few
miles, it was ok. Now, there's none of that.

Of course, the controller runs warmer, but last summer
proved that not to be an issue.

The A/C works well, but I'm only getting about a 25F drop
in temp from the vents. I'm planning on stopping by the
shop to see if we can top off the refrigerant. I know
we're not getting the same pressures that we bench tested

I also added some tint to the windshield for both IR and
UV blocking. I think it helps quite a bit and should
reduce the required cooling.

Oh, at this point, that's 4200 mi on the controller.
Assuming an average speed of 35 mph, that's 120 hours.

5-26-2010 169240 miles, 8438 miles electric

the batteries are loving the heat, i can pull a steady
100A at 60mph and arrive home at a higher voltage than a
few months ago when I'd try to limit it to 80A. it's
nice. There were even a string of cooler days that
get above 80 and I could notice the effect.

also got the remote a/c working. it works from the door
of my working building out to parking lot, so I can
start it up a few mins before i leave.

nearly 9k miles!

9-13-10 10k miles

had an episode with the controller. some internal
components shorted out and fried some things. amazingly,
the components were just a bolt and PCB. replacing one
diode, one mosfet, and two caps got it all working again.

5000 btu for an a/c is too small for AZ hot weather. I
get about a 20F drop in temperature from ambient. That's
ok if it's 100F outside. But, a different story when
115. 10k btu would be better - if that gives a 40F drop,
then that coupled with remote starting would be ideal, i
think. without remote starting, i think you'd need even


Well, i think i committed battricide. Apparently, as
FLA's age, they require a lower charge voltage. If you
don't set your charger lower, it'll just keep pumping
into the pack trying to get the voltage up. Batteries
heat up, lose a lot of water, maybe the plates warp or
something, but all the overcharging is bad.
Unfortunately, I didn't really know it was happening
I just plug it in and let it run overnight. Then, when I
normally check the water, it was abnormally low. That
was my first clue, which led to discovering the rest.

The pack would take significantly longer to get to 172V,
and once there, the current would only get down to around
13A before the timer expired (about a couple of hours).
Normally, it'd take just half an hour or so until the
current dropped to about 2A.

So, now about 8 of the 24 batteries have one or more bad
cells. Low SG and low voltage. They don't last long,
about 15 miles, but the rest should be ok. I'll work on
my charger in the meantime so I can have an adjustable
output. Then, I'll take the bad batteries out.

Though I didn't reach my goal of 20k miles on the pack,
I've been itching for a while to start the redesign to
switch to lithium batteries. It's gonna be a lot of
but I think the car will run great in the end.

- reinstall clutch
- find larger A/C compressor and install under the hood.
- build new racks for the lithium cells, possibly create
some more trunk space by putting cells where the spare
tire was. Maybe under the back seat too.
- finish charger
- build 900A controller
- build a BMS?

More fun and excitement!

9-26-2011 171,167 miles

Been a long journey to the present!

I had a coupler made from EV Coupler Connection to adapt
the flywheel so I could use the clutch again. I got that
finished and installed this past winter while I was still
able to test it out with the half dead lead acids. Works

In July, I bought and picked up the lithium cells from
CALB's warehouse in LA. I was there for a family event
anyway and their warehouse was a minor 2 mile detour -

The spare tire bay was removed and I built a tray to
carry 33 cells in its place. They are sunk enough that I
have most of a trunk! 2 more sets of 6 are on either
side of the trunk and out of the way in case I have long
and need to fold the seats down. I also built a
foam/fiberglass cover to keep the batteries somewhat

The electronics under the hood were completely re-done.
The fried dc-dc was replaced with an Iota (modified with
extra fans). I added a contactor to the negative side of
the controller and also a precharge relay to disconnect
the precharge resistor when the vehicle is off.

There were a lot of small things that i cleaned up. For
instance, the blower resistor for the vent fan only
worked for the medium and high speeds. To get a low speed, I
used a relay to switch in another resistor in series.
The whole thing resulted in a kludge of wires and switches.
I replaced it all with a homemade pwm controller. There
were some other things like this that were cleaned up.

I added a blower to the motor and an extra fan to the
controller heatsink. With the extra power of the lithium
cells, I suspect that I'll cruise at higher speeds. I'm
hoping the extra fans will allow the motor and controller
to still operate well at the higher speeds.

I built a BMS to monitor cell voltage consisting of a
master unit and 5 slaves that monitor 10 cells apiece
(except the last just monitors 5). It's kind of a hybrid
monitor/management system. In its current state, it only
monitor cell voltage and sounds an alarm if one goes too
high or too low. It also controls the charger if a cell
goes high. But, it has provisions to allow a balancing
board to plug into the slaves if they need to be
balanced. I haven't gotten this far yet since I suspect the
will stay in balance for a good length of time.

And, finally finished my charger which follows a CC/CV
charge algorithm. The finish voltage is less than the
BMS overvoltage threshold and so far the charger terminates
the charge cycle before the BMS does.

I haven't finished the a/c yet, but I have a plan. I
picked up a treadmill motor with a flywheel and plan to
use it to power the original model compressor.
Currently, I need to wait for some parts to be made. Also,
have to build a small controller to step the pack voltage
to 90V.

Well, so far there are 65 miles on the battery pack!

ticked over 1300 miles on the pack and about 32 cycles.
i just did my first capacity test which was a little
scary in the cooler temperatures. Over the course of two
days and several trips, I pulled 181 AH out of the pack
and 91 miles of driving.

The pack sagged pretty heavily after cold soaking to 45F
overnight at 60% DOD - I saw an average cell voltage of
maybe 2.95V on the way to work. At about 150AH used, I'd
hit the low voltage threshold of 2.5V under 200A
acceleration. At 181AH, the lowest cell would maintain
at 2.5V at 80A and I called it quits.

I hope most of this was due to the cold, but the heavy
voltage sag at the end of charge significantly limits the
energy capacity such that using half the AH is really
much more than half the range. I pulled 24.7 kwhr,
according to the cycle analyst. At 181 AH, and 45 cells,
that indicates an average cell voltage of 3.03V.

5-06-2013, 25000 miles!

Just finished the a/c. well, just got it working. I adapted
a 5hp 220VAC single phase motor to drive the original a/c
compressor with a belt drive. The pulleys make for about a
2:1 reduction ratio, so the compressor spins at about 1500

the motor gets power from a home-built inverter which takes
the 144V pack, boosts it to about 320VDC (peak voltage of
220VAC), then creates a sine wave output to power the motor.

Overall, it cools really well, but it does suck a bit of
power. So far, with temps in the mid 90's or so, it'll draw
about 20-22 amps from the battery pack while delivering 45F
air. I'm curious to see how this changes when we really get
into the hot part of summer.

Otherwise, the batteries, motor, and controller seem to be
holding up well. As of now, that's about 15k miles on the
battery and 22k miles on the controller.


Made it through the summer and the a/c kept up and kept it
cool. On the hottest days, the a/c motor and inverter would
get pretty hot, up to 70C in traffic, but things held

Some time last month I think, I did a range test and pulled
180 AH before the lowest cell was getting pretty low. I
looked back through this log and see that I stopped last time
when the lowest cell floated to only 2.8V or so - I didn't
get that far on this test.

I also don't see it here, but i did a range test when the
pack was about 9 months in use. It was a day where the high
was about 105 and I was able to get the full 200AH out of the
pack (though only rated for 180 AH, the packing list
indicated that they tested to 200 AH). So, it seems that
temperature, and i'm sure driving style and a whole host of
other things, greatly affect capacity.

I did another range test recently when it was a lot cooler,
maybe in the 50's at night, and was only able to pull 168 AH
(though I probably could've gone a bit more). Also, the
lowest cell voltage as indicated by my BMS is a different
cell than previously (cell 23 instead of 34). It does seem
that a cell or two may be aging faster than the others. At
some point in the future, I'd like to quantify this
difference. I was still able to drive 89 miles, though.

But, assuming that the 200AH test and the recent 180AH test
are similar conditions, and that the cells started out at 200
AH, that's a 10% loss in 2 years of driving. If it's linear,
then I'll a 50 mile range when the pack is 10 years old.
Still good for a 20 mile commute!

code by jerry