# [EVDL] Request for data on pack life for FLA and LiFePO4 in miles



## EVDL List (Jul 27, 2007)

Can folks reply with the typical life you have seen on your battery
packs? Ideally,
an answer that provides the number of miles and years or just miles is
preferred.



I converted my car using lead acid batteries but sold the battery pack and
put the car in storage 18 months ago when I had to go on a temporary
transfer to Utah for my job. I have returned and I am looking at a
financial comparison of purchasing a lead pack versus lithium. The biggest
variable that I can=92t put my finger on is battery life. I have read 100=
=92s
of opinions and seen all of the spec sheets on battery life of the different
technologies. I understand that lots of factors go into how long a battery
pack can live. I am simply looking for real world experience on how many
miles people have gotten out of a pack. I know Roland has gotten 8 years
out of a FLA pack that was well matched and cared for. How many miles or
cycles were put on that pack in those 8 years? My financial model assumes
400, 20 mile trips per year (2 trips per work day charging at work) or 8000
miles annually.
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## EVDL List (Jul 27, 2007)

"Can folks reply with the typical life you have seen on your battery packs?"

US2200XC, 144 volt pack
Now 2+ years old. ~12K miles, ~700 charges. 
Original max capacity ~35-40 miles.
Current max capacity ~15-20 miles.

Barry Oppenheim
New Hope, PA
www.JustAnotherEVConversion.blogspot.com


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## EVDL List (Jul 27, 2007)

Hopefully, you will have trouble finding anyone that has found the end life
point on their LiFePO4 cells. They haven't been out that long and should be
well into working life still. I have about 3000 miles on my lithium pack,
but that is only 5-6 months of driving. I drive about 50 miles per day with
charging in each end. I had the car up on jack stands for most of the
winter doing some rewiring, though. I'm hoping I get 5-6 years and 50,000
to 60,000 miles, but I won't know for 4-5 more years. 8^)

Mike
www.evalbum.com/2778


> -----Original Message-----
> From: [email protected] [mailto:[email protected]] On
> Behalf Of Steve Skarda
> Sent: Thursday, May 12, 2011 11:46 AM
> To: Electric Vehicle Discussion List
> Subject: [EVDL] Request for data on pack life for FLA and LiFePO4 in miles
> 
> Can folks reply with the typical life you have seen on your battery packs?
> Ideally, an answer that provides the number of miles and years or just
miles
> is preferred.
> 
> 
> 
> I converted my car using lead acid batteries but sold the battery pack and
put
> the car in storage 18 months ago when I had to go on a temporary transfer
to
> Utah for my job. I have returned and I am looking at a
> financial comparison of purchasing a lead pack versus lithium. The
biggest
> variable that I can't put my finger on is battery life. I have read 100's
of
> opinions and seen all of the spec sheets on battery life of the different
> technologies. I understand that lots of factors go into how long a
battery
> pack can live. I am simply looking for real world experience on how many
> miles people have gotten out of a pack. I know Roland has gotten 8 years
> out of a FLA pack that was well matched and cared for. How many miles or
> cycles were put on that pack in those 8 years? My financial model
assumes
> 400, 20 mile trips per year (2 trips per work day charging at work) or
8000
> miles annually.
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## EVDL List (Jul 27, 2007)

Short answer -
US8VGC, 48 volt pack 5,829 miles, ~600 charges
Now 3.5+ years old
Original max range: ~25 miles
Current max range: ~17 miles
Replacing the pack this Summer.

Longer answer -

I bought my pack in August 2007. Although the vehicle is somewhat small,
the charge/discharge cycle is likely to be similar to a larger pack in a
larger vehicle.

The batteries are 6 each US Battery US8VGC 8-volt flooded batteries. When
new, the 48v, 6.1 kWh pack had a 25 mile range (drove that far twice -
charge was very low at the end both times...) Recently, about the farthest
I've driven it is 15 miles before I plug it in. It gets a bit sluggish at
15 miles, but could probably do 17 miles if needed. 

Typical efficiency in this Citicar is about 230 wh/mi.

Maximum startup current is about 450 battery amps - limited by the
controller maximum. Typical cruise power is 90-120 battery amps.

Since it was installed, I've driven the Citicar 5,829 miles on this pack. I
use it as a commuter car for my 4.5 mile drive to work a few days a week -
more in the summer, less in winter. A typical day sees 4.5 miles to work,
parked for nine hours (no working outlets in the parking lot...), than drive
it 4.5 miles home and charge for about 3 hours. Charger puts out about 25
amps @ 48 volts. Timer charger (not a modern item - just a transformer...)

This vehicle has been out of service for two extended periods of time (about
two months each time) and the battery pack was topped up about once a week
during these intervals. Each time, the pack took a dozen or so charging
cycles to wake up once I had it back on the road. Both times it appeared to
permanently lose a few miles of range after being inactive for such a long
period. The batteries seem much happier if they are used every day.

Tom Keenan


-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of Barry Oppenheim
Sent: Thursday, May 12, 2011 10:58 AM
To: 'Electric Vehicle Discussion List'
Subject: Re: [EVDL] Request for data on pack life for FLA and LiFePO4 in
miles

"Can folks reply with the typical life you have seen on your battery packs?"

US2200XC, 144 volt pack
Now 2+ years old. ~12K miles, ~700 charges. 
Original max capacity ~35-40 miles.
Current max capacity ~15-20 miles.

Barry Oppenheim
New Hope, PA
www.JustAnotherEVConversion.blogspot.com


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## EVDL List (Jul 27, 2007)

A bit under 18 months, bit over 10,000 miles, range and performance same as
when new as far as I can tell. CALB LiFePO4 cells.

--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Request-for-data-on-pack-life-for-FLA-and-LiFePO4-in-miles-tp3518210p3520245.html
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## EVDL List (Jul 27, 2007)

> tomw wrote:
> > A bit under 18 months, bit over 10,000 miles, range and performance same as
> > when new as far as I can tell. CALB LiFePO4 cells.
> 
> ...


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## EVDL List (Jul 27, 2007)

From: Barry Oppenheim
> Can folks reply with the typical life you have seen on your battery packs?

Pack #1: Twelve cheap 6v golf cart batteries in a 1974 Datsun pickup. 
First EV, made lots of mistakes. Pack lasted 2 years and about 8k miles, 
with a few replacments along the way.

Pack #2: Fourteen Exide EV-106 6v golf cart batteries, in a custom built 
micro-van EV. Pack lasted 4 years and about 12k miles, down to about 50% 
capacity at the end.

Pack #3: Twelve Sam's Club T-105 type golf cart batteries, in a 
ComutaVan. Lasted 7 years, 18k miles; one failure (replaced) at about 5 
years.

Pack #4: Twelve Concorde 12v 95ah AGMs, in a 1980 Renault LeCar. Lasted 
10 years, 22k miles, down to about half capacity at the end. 3 batteries 
failed along the way and were replaced or wired around.

Pack #5: Fifteen Sam's Club 8v golf cart batteries, in the same LeCar. 
About a year old, and still working out the bugs so not many miles yet.
-- 
Lee A. Hart | Ring the bells that still can ring
814 8th Ave N | Forget the perfect offering
Sartell MN 56377	| There is a crack in everything
leeahart earthlink.net	| That's how the light gets in -- Leonard Cohen

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## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> 
> > Pack #4: Twelve Concorde 12v 95ah AGMs, in a 1980 Renault LeCar. Lasted
> > 10 years, 22k miles, down to about half capacity at the end. 3 batteries
> ...


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## EVDL List (Jul 27, 2007)

> Lee Hart wrote:
> >> Pack #4: Twelve Concorde 12v 95ah AGMs, in a 1980 Renault LeCar. Lasted
> >> 10 years, 22k miles, down to about half capacity at the end. 3 batteries
> >> failed along the way and were replaced or wired around.
> ...


----------



## EVDL List (Jul 27, 2007)

Thank you for the responses. 10,000 miles out of FLA or 40,000 miles out of
LiFePO4. Which is more realistic for the average DIYr?


Based on these limited data points and a few others I found in the archives,
I have completed a simple cost comparison on lead vs. lithium and concluded
that for my particular EV and driving condition, if I was able to get
greater than 10,000 miles out of a FLA pack, lead acid is a far better value
than LiFePO4 at today's costs. However, getting 10k miles out of FLA
requires diligent maintenance and care. Many of us haven't reached that
milestone using FLA (myself included). In those instances, LiFePO4 may
offer a better value. LiFePO4 has a more consistent positive payback as
long as a person can get a minimum of 40k miles or 2000 cycles out of a
single LiFePO4 pack. No one to my knowledge has gotten to the normal end of
a life for a LiFePO4 battery pack but Willie=92s early data suggests this
might be obtainable.


Please let me know if you see any obvious flaw in my analysis or
conclusions.


ROR Results:**

FLA with 800 cycles, 8k miles (1 year life) =3D -20%

FLA with 1200 cycles, 12k miles (18 month)=3D +18%

FLA with 1600 cycles, 16k miles (2 year life) =3D +37%

LiFePO4 with 1600 cycles, 32k miles (4 year life)=3D -5%

LiFePO4 with 2000 cycles, 40K miles (5 year life) =3D +3.5%

LiFePO4 with 2800 cycles, 56k miles (7 year life) =3D +12.3%

LiFePO4 with 4000 cycles, 80k miles (10 year life) =3D +18%



Base Case =96 Gas Guzzler**

20 MPG

200 work days, 20 mile one way commute, charging at work

400 trips at 20 miles each, freeway with moderate hills

$4/gal

$1600/year in gasoline costs

Electric car sitting in driveway in need of a battery pack

*analysis excludes other maintenance costs such as oil changes



FLA Option:**

20, 205AH Sam=92s Club Golf Cart Batteries

40 mile range

1220 lbs

20*$75+6% tax+$50 membership=3D$1640

$300 charging/year
6V*20*225AH=3D27kwh

Peukert Number of Lead Acid =3D 1.2

Average 100 amps (120V)

Peukurt equation results in 40% of 27 or 11kwh



*LiFePO4 Option*

45, 100AH TS

40 mile range

350lbs

45*$125+$250 shipping=3D$5875

$300 charging/year

3.2V*45*100AH=3D14.4kwh

Peukert Number of LiFePO4=3D1.05

Average 83 amps (144V)

Peukert equation results in 80% of 14.4 or 11kwh (roughly equal to 120V FLA
pack)

*Note: This is still not perfect apples to apples but close enough. Peuk=
ert
values are estimated (probably low for lead acid) and reduced weight of car
is not considered. Both would result in better results for LiFePO4.
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## EVDL List (Jul 27, 2007)

Hi Steve,

If you are trying to compare best-case scenarios, then TS Yittrium cells ar=
e rated to 5,000 cycles at 70% DOD. Also don't forget that Lee said he repl=
aced a few batteries along the way, so you need to take that into considera=
tion too.

I haven't responded with information from my pack because it is so new. I h=
ave only 3100 miles over the past 3 or 4 months. I typically discharge to 5=
0-60% SOC, and never have gone lower than 30% SOC (I think....but that's an=
other story). I haven't tested capacity (ever). =


--corbin




> Steve Skarda wrote:
> 
> > Thank you for the responses. 10,000 miles out of FLA or 40,000 miles out =
> of
> ...


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## EVDL List (Jul 27, 2007)

> corbin dunn wrote:
> > Hi Steve,
> >
> > If you are trying to compare best-case scenarios, then TS Yittrium cells are rated to 5,000 cycles at 70% DOD. Also don't forget that Lee said he replaced a few batteries along the way, so you need to take that into consideration too.
> ...


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## EVDL List (Jul 27, 2007)

> Willie McKemie <[email protected]> wrote:
> 
> >
> > I would urge prospective LFP users to consider using 160ah as a minimum
> ...


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## EVDL List (Jul 27, 2007)

> Steve Skarda wrote:
> > On Tue, May 17, 2011 at 7:05 PM, Willie McKemie <[email protected]> wrote:
> >
> > >
> ...


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## EVDL List (Jul 27, 2007)

My 100 AH Hi-Power cells do see above the minimum 1C rating for these older
Hi-Power cells. I am then assuming that hitting them hard like I do will
shorten the life. I have lots of mile yet to put on them but so far nothing
noticeable has happened. I'd agree that if you can get cells that are newer
and have a higher AH rating like 160 or more you'd be better off or if you
use a pack of 100 AH cells at a very high voltage like into the 200 + volts
for your pack. At 96 volts your cells are hit real hard in amp draw if you
want to do any driving at any decent speeds. At 120 it is better. I can
drive in second at 45 mph and keep my amp draw in the 45 to 55 amp range. At
freeway speeds of 55 or higher that jumps to 120 to 220 amps in 3rd and 4th
and up to 65 mph. Above 45 the amp draw just jumps. That is hard on cells
rated for 1C continuous. But so far they are living just fine. I'd like to
try 156 volts and see how the amps are at that voltage level but I don't
have a charger that can charge that high. Max voltage of my bulk manual
charger is 150 volts. I think I will stay at 120 volts for now. 

Pete 

-----
If you don't understand, be patient, you will. Now I understand. 
--
View this message in context: http://electric-vehicle-discussion-list.413529.n4.nabble.com/Request-for-data-on-pack-life-for-FLA-and-LiFePO4-in-miles-tp3518210p3532721.html
Sent from the Electric Vehicle Discussion List mailing list archive at Nabble.com.

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## EVDL List (Jul 27, 2007)

For clarification, I used 100AH, 144V pack in my analysis because it looked
to me like a 100AH pack of 45 cells would most fairly represent the same
range and speed as a 120V pack of golf cart batteries. I appreciate
Willie's comments because I don't mean to suggest that is a good
recommendation for an EV.

When I run ROR's on the larger pack, the only variable that I know how to
change is cost since we don't have enough data to know how much longer life
you'd get out of a 200ah pack for the same car. As a result, the ROR's
drop about 10% based on extra cost and lead acid looks even better.
However, it is not really a fair comparison since you are getting a great
deal of added performance from a 200AH pack that you don't get from lead in
terms of range and acceleration (reduced weight and increased amp
capability).
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## EVDL List (Jul 27, 2007)

> Willie McKemie wrote:
> > It's pretty rare for a lead pack to reach 10K miles. There are MANY
> > tales of people murdering their lead packs at an early age.
> 
> ...


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