Update on A123 Prismatic LIFEPO4 battery
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Bike_On
Jun 7, 2011, 12:10:39 AM6/7/11
to Optibike Owners Group
I don't have it **YET**. I laid out the cash on Mar 28th, and I'm
still waiting. Lost of reasons...ok the Opti work crew can feel good
about all the R&D punching out a ready product.
My battery has had some experimentation in the production
process...bad for delivery. Part of the issue is me being picky about
what I want. Here is what changed:
1. The connector discharge/charge arrangement had too much loss. It
wa slike 120mohms, when the cells should only total 8mohms
themselves. I said no-go and FalconEv will lasar weld the tabs. I
am back to a BMS, no current limit, 50A fuse. We are using a lithium
charger and manually bumping up the voltage for 13S at 46.8V. My pack
goal is 25 mohms. We are waiting on a small volt meter. Pack size,
in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
Summer days are about to be burned....let you all know when I can.
still waiting. Lost of reasons...ok the Opti work crew can feel good
about all the R&D punching out a ready product.
My battery has had some experimentation in the production
process...bad for delivery. Part of the issue is me being picky about
what I want. Here is what changed:
1. The connector discharge/charge arrangement had too much loss. It
wa slike 120mohms, when the cells should only total 8mohms
themselves. I said no-go and FalconEv will lasar weld the tabs. I
am back to a BMS, no current limit, 50A fuse. We are using a lithium
charger and manually bumping up the voltage for 13S at 46.8V. My pack
goal is 25 mohms. We are waiting on a small volt meter. Pack size,
in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
Summer days are about to be burned....let you all know when I can.
chessmonster
Jun 7, 2011, 1:13:46 AM6/7/11
to Bike_On, Optibike Owners Group
Why are you guys still wasting your time with big and bulky lifepo4's?
Take a page out of opti'sand lfp's play book and go lipo...
Need help sourcing a battery?
I had 2 37 volt 20 amp hour lipo packs made in china that obviously i
dont need anymore....I just took them out of the box tonight...
They put out 30 amps continuous with up to 50 amp bursts.
I have tested extensively the 48 volt packs and they work great.
These lipos have built in bms that not only protect the battery from
overcharge or discharge, but also balance charge the individual
cells....
Also have a 36v 3 amp charger included...you can see battery and
charger in video.
http://www.youtube.com/watch?v=SeGO6WNzS8Y
As you can see it is a very dense pack...a topeak pack would fit 2 easily.
Let me know if anyone is interested in these. USV man? Want to take a
weight off your back?
How does $800 sound? My cost + $58 from china.
Bike_On
Jun 23, 2011, 5:42:17 PM6/23/11
to Optibike Owners Group
Chess,
My prismatics can put out 200A cont (10C), 600A peak (30c), and are
rated for 1500-2000 cycles, vs lipo 30A cont and maybe 300 cycles?
What is you total $ per 1kwhr?
Mine is: $1300/(20*42*2000)/1000 = $0.77
My energy density is 142 wh/kg. Bulky??
D
> > Summer days are about to be burned....let you all know when I can.- Hide quoted text -
>
> - Show quoted text -
My prismatics can put out 200A cont (10C), 600A peak (30c), and are
rated for 1500-2000 cycles, vs lipo 30A cont and maybe 300 cycles?
What is you total $ per 1kwhr?
Mine is: $1300/(20*42*2000)/1000 = $0.77
My energy density is 142 wh/kg. Bulky??
D
>
> - Show quoted text -
Nicholas Turner
Jun 23, 2011, 6:43:49 PM6/23/11
to optibike-o...@googlegroups.com
The Optibike only needs roughly 3c burst for very short times and 1c continuous, any more is a waste of space and weight. Generally any EV should only need those requirements, if it needs more than that your runtime, weight and other things will suffer.
Have you checked what temp that cycle life is at? LiFePo4 does have the issue of not being able to handle high temps (45-50c and up) and still retain that cycle life. They typically test them while the packs are cooled.
Have you checked what temp that cycle life is at? LiFePo4 does have the issue of not being able to handle high temps (45-50c and up) and still retain that cycle life. They typically test them while the packs are cooled.
Bike_On
Jun 24, 2011, 1:37:53 PM6/24/11
to Optibike Owners Group
Nich,
I don't know the specific conditions for the life cycle. Here is what
I found:
A123 LiFePO4 20 Ah Cell Specifications:
Normal Voltage: 3.3V
Capacity (1C to Vmin=2.0V): minimum 18.5AH, typical 20Ah
Whr/Cell: 64.6
Volume (l): 0.263
Operating Temperature: -30c to 55C
Storage temperature: -40C to 60C
Number of Cycles : minimum 300, typical 2000
Max Discharge (SOC and Temp dependent): 300Amps
Max Charge (SOC and Temp dependent): 300Amps
Wh/Liter: 245.6
Self Discharge @ 25C: <2%/month
Dimensions (mm) 7.25 x 160 x 237 / .3 x 6.3 x 9.7” top of tabs
Weight (g) 496 / ONE lb.
Nominal Voltage and maximal / minimal discharge voltage (recommended
and critical) 3.3 nom, 3.6 max, 4.0 critical. 2.0V min, 1.0V
critical
Internal resistance: .5 mOhm nominal
Specific Power (nominal, W/kg): 2400
Specific Energy (nominal, Wh/kg): 131
Maximal current discharge rate: 300A cont, 750 peak / 15C – 37C rated
Yes, the Opti operates at 3c peak (60A) and 1c cont (20A). The life
cycle of this battery will be long indeed, for a 30C cell, operating
at 1C. BEcause of the low internal resistance, it will not be hot at
all, when operating an Opti and should last the full life is just used
for that.
The second benefit is a flatter discharge curve over Lipo. While lipo
10S pack goes from 41.5V to 34 V on the Opti over the 20 ahrs, the
LIFEPO 13S will go from 41.6V to 39V (estimated) . That will mean
sustained power on the second half of the long commutes/rides.
Do you know the cell impedance of the Opti cells? Can you say? The
bare A123 prismatics measure 0.57 milliohms. Yes, that's a decimal
BEFORE the 5. There is a pic on FalconEv.com.
I do not question that the newer, high 30C lipos are lighter and just
as high power density. Nobody operates those cells at that high of
output, unless they want a short life. The lifepo nano pack should be
fine up through 5C. Above that, the discharge will drain the pack too
fast for much of a ride anyway, and I'd need parallel packs.
There are very FEW tradeoffs in using the A123 prismatics. Weight-
sort of, cost- moderate.
I don't know the specific conditions for the life cycle. Here is what
I found:
A123 LiFePO4 20 Ah Cell Specifications:
Normal Voltage: 3.3V
Capacity (1C to Vmin=2.0V): minimum 18.5AH, typical 20Ah
Whr/Cell: 64.6
Volume (l): 0.263
Operating Temperature: -30c to 55C
Storage temperature: -40C to 60C
Number of Cycles : minimum 300, typical 2000
Max Discharge (SOC and Temp dependent): 300Amps
Max Charge (SOC and Temp dependent): 300Amps
Wh/Liter: 245.6
Self Discharge @ 25C: <2%/month
Dimensions (mm) 7.25 x 160 x 237 / .3 x 6.3 x 9.7” top of tabs
Weight (g) 496 / ONE lb.
Nominal Voltage and maximal / minimal discharge voltage (recommended
and critical) 3.3 nom, 3.6 max, 4.0 critical. 2.0V min, 1.0V
critical
Internal resistance: .5 mOhm nominal
Specific Power (nominal, W/kg): 2400
Specific Energy (nominal, Wh/kg): 131
Maximal current discharge rate: 300A cont, 750 peak / 15C – 37C rated
Yes, the Opti operates at 3c peak (60A) and 1c cont (20A). The life
cycle of this battery will be long indeed, for a 30C cell, operating
at 1C. BEcause of the low internal resistance, it will not be hot at
all, when operating an Opti and should last the full life is just used
for that.
The second benefit is a flatter discharge curve over Lipo. While lipo
10S pack goes from 41.5V to 34 V on the Opti over the 20 ahrs, the
LIFEPO 13S will go from 41.6V to 39V (estimated) . That will mean
sustained power on the second half of the long commutes/rides.
Do you know the cell impedance of the Opti cells? Can you say? The
bare A123 prismatics measure 0.57 milliohms. Yes, that's a decimal
BEFORE the 5. There is a pic on FalconEv.com.
I do not question that the newer, high 30C lipos are lighter and just
as high power density. Nobody operates those cells at that high of
output, unless they want a short life. The lifepo nano pack should be
fine up through 5C. Above that, the discharge will drain the pack too
fast for much of a ride anyway, and I'd need parallel packs.
There are very FEW tradeoffs in using the A123 prismatics. Weight-
sort of, cost- moderate.
chessmonster
Jun 24, 2011, 7:41:07 PM6/24/11
to Bike_On, Optibike Owners Group
my lipo is rated for 300-500 charges if you drain all the way...over a thousand if you generally do not drain all the way on most of your rides.
Its hard to find a lipo pack complete with its own bms which is what i got.
My bms has low voltage cut off, amperage limit, plus balance charging and over charge protection.
The real benefit of lipo is size and weight.
Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it have a bms? a123's are very bulky and heavy for this usage imo....and you really dont need that kind of amperage output for opti.
Also what is the pack costing you in $?
chessmonster
Jun 24, 2011, 7:53:54 PM6/24/11
to Bike_On, Optibike Owners Group
Ok got it in your earlier email...but please send pictures or video when you get pack...will it fit in topeak bag or no? If not where do you plan to mount it? Backpack?
in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
Bike-ons 36v 20ah a123 pack
in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
2000 charges if your careful
BMS?
$1300
chessmonsters 36volt 20ah lipo pack
6x4.5x3.5
9lbs
BMS
300-500 full charges
$850
Built and in hand (see youtube video)
Nimbuzz
Jun 25, 2011, 7:24:30 AM6/25/11
to Optibike Owners Group
What youtube video might that be?
On Jun 24, 4:53 pm, chessmonster <chessmons...@gmail.com> wrote:
> Ok got it in your earlier email...but please send pictures or video when you
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
On Jun 24, 4:53 pm, chessmonster <chessmons...@gmail.com> wrote:
> Ok got it in your earlier email...but please send pictures or video when you
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> On Fri, Jun 24, 2011 at 4:41 PM, chessmonster <chessmons...@gmail.com>wrote:
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
Bike_On
Jun 29, 2011, 11:48:46 AM6/29/11
to Optibike Owners Group
Safety:
Chessmonster : Has to have a BMS for Lipo temps monitoring.
Bike_on: Optional
On Jun 24, 7:53 pm, chessmonster <chessmons...@gmail.com> wrote:
> Ok got it in your earlier email...but please send pictures or video when you
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> >> > cooled.- Hide quoted text -
Chessmonster : Has to have a BMS for Lipo temps monitoring.
Bike_on: Optional
On Jun 24, 7:53 pm, chessmonster <chessmons...@gmail.com> wrote:
> Ok got it in your earlier email...but please send pictures or video when you
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> On Fri, Jun 24, 2011 at 4:41 PM, chessmonster <chessmons...@gmail.com>wrote:
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
Bike_On
Jun 29, 2011, 11:51:09 AM6/29/11
to Optibike Owners Group
Cost per charge cycle:
Chess: 850/500/300 = $1.7-$2.83
Bike _on: 1300/2000/1500= $0.65-0.87
Chess: 850/500/300 = $1.7-$2.83
Bike _on: 1300/2000/1500= $0.65-0.87
> Ok got it in your earlier email...but please send pictures or video when you
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> On Fri, Jun 24, 2011 at 4:41 PM, chessmonster <chessmons...@gmail.com>wrote:
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
Bike_On
Jun 29, 2011, 11:55:17 AM6/29/11
to Optibike Owners Group
I do have a BMS for charge balancing. Current limit is a fuse, no BMS
on discharge. Buzzer for LVC. CA for voltage monitoring with
installed visible meter as backup.
I think this price can be less, but it is actually a good value for
A123 cells. Lipo is awesome on the size/weight.
Which one can handle 40A of Tidalforce regen better?
on discharge. Buzzer for LVC. CA for voltage monitoring with
installed visible meter as backup.
I think this price can be less, but it is actually a good value for
A123 cells. Lipo is awesome on the size/weight.
Which one can handle 40A of Tidalforce regen better?
> Ok got it in your earlier email...but please send pictures or video when you
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> get pack...will it fit in topeak bag or no? If not where do you plan to
> mount it? Backpack?
>
> Bike-ons 36v 20ah a123 pack
> in metal case, is 10.5x7x4.5 inches. Weigh should be 13-15lbs.
> 2000 charges if your careful
> BMS?
> $1300
>
> chessmonsters 36volt 20ah lipo pack
> 6x4.5x3.5
> 9lbs
> BMS
> 300-500 full charges
> $850
> Built and in hand (see youtube video)
>
> On Fri, Jun 24, 2011 at 4:41 PM, chessmonster <chessmons...@gmail.com>wrote:
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
>
>
>
> > my lipo is rated for 300-500 charges if you drain all the way...over a
> > thousand if you generally do not drain all the way on most of your rides.
>
> > Its hard to find a lipo pack complete with its own bms which is what i
> > got.
>
> > My bms has low voltage cut off, amperage limit, plus balance charging and
> > over charge protection.
>
> > The real benefit of lipo is size and weight.
>
> > Bike-on...can you attach a picture of your 20ah 36v a123 pack? Does it
> > have a bms? a123's are very bulky and heavy for this usage imo....and you
> > really dont need that kind of amperage output for opti.
>
> > Also what is the pack costing you in $?
>
Bike_On
Jul 7, 2011, 1:40:43 PM7/7/11
to Optibike Owners Group
BAttery packed and being shipped. Pics will follow.
37 milli ohm impedance at terminals.
It will be nice to ride the Opti at full power again. My commutes to
work have averaged about 22.2 mph and I am running at 34.5V, 450W
after 18 miles. Pretty weak.
> > - Show quoted text -- Hide quoted text -
37 milli ohm impedance at terminals.
It will be nice to ride the Opti at full power again. My commutes to
work have averaged about 22.2 mph and I am running at 34.5V, 450W
after 18 miles. Pretty weak.
Bike_On
Jul 9, 2011, 11:49:16 PM7/9/11
to Optibike Owners Group
It arrived! Pics of battery:
http://optibikepics.shutterfly.com/pictures
I commented in pics. Initial impression: cumbersome with the extra
13th cell for wiring, balancing etc.
I did hook it up to the Opti Aux input. Details later after better
checkout. Sneak comment: Opti controller chokes off power more than I
had hoped.
Dan
http://optibikepics.shutterfly.com/pictures
I commented in pics. Initial impression: cumbersome with the extra
13th cell for wiring, balancing etc.
I did hook it up to the Opti Aux input. Details later after better
checkout. Sneak comment: Opti controller chokes off power more than I
had hoped.
Dan
Bike_On
Jul 11, 2011, 3:27:58 PM7/11/11
to Optibike Owners Group
Big setback yesterday... bottom line, I killed a cell in my new pack.
Oh, the joys of a DIY hobbyist.
I rode off about 3 ahrs and then went to top off the charge.
Cell charger #1 (4A) set to 13x3.6=46.8V. Cell charger 2 (10A) set to
3.6V for 1 cell only. I plugged in both (one accross 13, one accross
1) Ran 10 min, Stopped at 46V or so. 12 cells still around 3.4V,
13th at 4.0V!!
The next day, the cell has expanded and ruptured the case. See pics
on web site...
So I send it back to replace. I am considering just going with 12
cells, but Iintend to get a 20 ahr ride and NEVER see the 34V safe
mode!!! We shall see.
BTW: I rode 26 mies on Sunday. Half with the new battery until the
cell went to 0 volt. Then ran on Opti battery. Powe rusage was a
standanrd 25-26 whr per mile, just like the Opti battery when fresh
charged. The controller seems to be keeping a constant power steady
state output around 700 watts. This is true at 43V, 39V and 36V.
This means the current and tourque are less in the same gear.
Top speed on downhill, full throttle: 39 mph but under 600W-650W. The
new battery, with a higher voltage is kind of like getting a higher
gear with no power increase!!! Argh!
More later. Battery will get sent back. Visions of a full summer
running 900-1000W and 25+mph averages fading fast.
Dan
PS. Impedance snapshot
Circuit: Battery, cable, relay CCA (switch, fuse, relay, PWB trace,
connecotrs), CA interface (2 molex connecors, current sense)
Opti battery in circuit: 180 mohm
2011 A123 battery at vendor: 37 mohm
2011 A123 in circuit: 90 mohm
circuit impednace: 53 mohm
2009 Opti battery: 180-53 - 127 mohm.
Oh, the joys of a DIY hobbyist.
I rode off about 3 ahrs and then went to top off the charge.
Cell charger #1 (4A) set to 13x3.6=46.8V. Cell charger 2 (10A) set to
3.6V for 1 cell only. I plugged in both (one accross 13, one accross
1) Ran 10 min, Stopped at 46V or so. 12 cells still around 3.4V,
13th at 4.0V!!
The next day, the cell has expanded and ruptured the case. See pics
on web site...
So I send it back to replace. I am considering just going with 12
cells, but Iintend to get a 20 ahr ride and NEVER see the 34V safe
mode!!! We shall see.
BTW: I rode 26 mies on Sunday. Half with the new battery until the
cell went to 0 volt. Then ran on Opti battery. Powe rusage was a
standanrd 25-26 whr per mile, just like the Opti battery when fresh
charged. The controller seems to be keeping a constant power steady
state output around 700 watts. This is true at 43V, 39V and 36V.
This means the current and tourque are less in the same gear.
Top speed on downhill, full throttle: 39 mph but under 600W-650W. The
new battery, with a higher voltage is kind of like getting a higher
gear with no power increase!!! Argh!
More later. Battery will get sent back. Visions of a full summer
running 900-1000W and 25+mph averages fading fast.
Dan
PS. Impedance snapshot
Circuit: Battery, cable, relay CCA (switch, fuse, relay, PWB trace,
connecotrs), CA interface (2 molex connecors, current sense)
Opti battery in circuit: 180 mohm
2011 A123 battery at vendor: 37 mohm
2011 A123 in circuit: 90 mohm
circuit impednace: 53 mohm
2009 Opti battery: 180-53 - 127 mohm.
Nicholas Turner
Jul 12, 2011, 11:37:57 AM7/12/11
to optibike-o...@googlegroups.com
I have not heard of A123 cells having trouble with small overcharges before, I wonder what caused the cell to expand
Bike_On
Jul 12, 2011, 2:12:52 PM7/12/11
to Optibike Owners Group
I accidentally charged it to 4.0 V. All that happened was a bulging
pouch. A lot prettier than the Lipo pack you just posted!!
pouch. A lot prettier than the Lipo pack you just posted!!
Nicholas Turner
Jul 12, 2011, 8:51:59 PM7/12/11
to optibike-o...@googlegroups.com
Is there a reason they gave you 2 chargers instead of just one with a slightly cranked up voltage output?
I would imagine something to do with the BMS in there
I would imagine something to do with the BMS in there
Bike_On
Jul 14, 2011, 12:29:26 AM7/14/11
to Optibike Owners Group
Nic-
BMS were cell balancers on S1-S12.
Charger bumped up for 13 S.
2nd charger (3.6V) was suppose to top off S13 if needed, but I charged
it along with the 13S and it overshot.
BMS were cell balancers on S1-S12.
Charger bumped up for 13 S.
2nd charger (3.6V) was suppose to top off S13 if needed, but I charged
it along with the 13S and it overshot.
Bike_On
Aug 2, 2011, 1:13:41 PM8/2/11
to Optibike Owners Group
I HAVE IT....finally. Got it last week but had to do some self-
improvement mods to get it ready....long story in working with
FalconeV to get it right, and it's not right. Refund not an option so
I'm stuck to make it work.
On the bright side, the cells are strong and assembled, so I'm ready
to test and experiement with a future E+ or other hub platform.
I will be downloading pics to my website. Here are some specs:
13 series A123 prismatic cells, 20 ahr rated, 30C max.
No BMS
Use cell buzzers/meter for LVC (2.7V).
Charging is tricky and being developed. Given 2 boards for 6 cell
balancers...they kind of work, but I don't fully trust them. My first
experience with battery balancing on a DIY. I already puffed one
pouch. I re-wired and adjusted my charger for 12S @ 42V, 4A. I have
a single 3.7V, 2A for #13 with seperate leads. When the cells get out
of balance, a few start to spike towards the end of the charge cycle.
It's a real pain at the moment until I figure out a method and cycle a
few time.
I added an alum metal plate for compression. Only had room on one
side.
Includes a 50A fuse.
wt: 13lbs...in my topeak pack, with chargers and bike tools, the
Topeak weighted 24 lbs!!! I have a reinforced seatpost rack, but I
worry.
1st Commute Report:
23.2 miles, 1:1:50, 22.7 mph ave
Total, Motor, Human, Battery
2118 calories of energy
640.4 whrs, 506, 134, 595.5
621.5 Watts Ave, 491, 130.3, 578
27.4 whr/mi total, 25.5 whr/mi battery
Details:
Voltage started around 43.5-44V and quickly leveled to 42V under
load. I was dropping about a volt, but at limited current power of
est 15A, 650W. I checked impedance 2x and both were about 100
milliohms at the CA meter. Ended the ride at 40V under load.
Running at 42 V, the Opti center cadence sweet spot moved up about 10
rpm from 85 to 95. The min rpm on a new charge moved from 80 to 90
rpm. On my 2 yr old battery, I run at 78 rpm under load, and only
because it it degrading the the voltage is around 36.5V. At 42V,
plenty of voltage and power.
PROBLEM :: The controller is limiting the power/current. Bost mode
work great and is uninhibited. I see 870-950W in boost for 2-3 sec.
During steady state, the bike only want to put out 15 amps and
650-670W before i feel a phase back under increasing loading. Thus,
instead of upping the juice and giving me the speced 850W steady
state, my controller just allow limits around 670W and lets the rpms
fall as load increased. Disappointing! If I push the pedals hard and
stay in the 92-95 rpm range, current is 15 amps typ and tin the sweet
spot.
Down hill, the speed tops out at 38-39mph at 42-43V !!
It is interesting that my stock 36V opti battery will give me 18-19
amps steady state, which give more torque when riding.
The higher voltage should allow for a few more watts to get to the
motor, but the opti guys have it programmed for efficiency.
I had the exact ride a couple weeks ago and was pushing hard and had
the EXACT same average! However, battery usage was 19.6 whr/mi vs
25.5 today. I expect I am running less eff because I can't keep the
95rpm and am loading it harder. Other results have seen a 21.5 mph
average for that ride, so the new battery did give me a 1mph bump
without any extra effort over the stock 2 yr old battery.
Summary:
1. The A123 at 43V gives about the same speed performance as the
stock OPti on average speed...so far. High end speed on flats and
hills is higher. Torque on hills is LOWER.
2. The 43 V makes the cadence a little high for my preference. I
like 85 rpm centered.
3. The new pack did give me a slightly higher average power, only
because it stays flat the and stock is dropping off at 10 miles.
Average battery watts were 578 vs 480 watts typical. I expect a new
Opti battery was up there near 600W average for a ride.
4. At this time, ther eis nothing I can do to get more power out of
my Optibike. The estimate average power from the motor, running at
85% eff, is 500W. My old battery is giving me 350-400W ave during a
22 mile ride. For an 850W system, I don't understand why the steady
state is limited. It must be a limit on the operating range of the
motor??
More later..back to work.
Dan
improvement mods to get it ready....long story in working with
FalconeV to get it right, and it's not right. Refund not an option so
I'm stuck to make it work.
On the bright side, the cells are strong and assembled, so I'm ready
to test and experiement with a future E+ or other hub platform.
I will be downloading pics to my website. Here are some specs:
13 series A123 prismatic cells, 20 ahr rated, 30C max.
No BMS
Use cell buzzers/meter for LVC (2.7V).
Charging is tricky and being developed. Given 2 boards for 6 cell
balancers...they kind of work, but I don't fully trust them. My first
experience with battery balancing on a DIY. I already puffed one
pouch. I re-wired and adjusted my charger for 12S @ 42V, 4A. I have
a single 3.7V, 2A for #13 with seperate leads. When the cells get out
of balance, a few start to spike towards the end of the charge cycle.
It's a real pain at the moment until I figure out a method and cycle a
few time.
I added an alum metal plate for compression. Only had room on one
side.
Includes a 50A fuse.
wt: 13lbs...in my topeak pack, with chargers and bike tools, the
Topeak weighted 24 lbs!!! I have a reinforced seatpost rack, but I
worry.
1st Commute Report:
23.2 miles, 1:1:50, 22.7 mph ave
Total, Motor, Human, Battery
2118 calories of energy
640.4 whrs, 506, 134, 595.5
621.5 Watts Ave, 491, 130.3, 578
27.4 whr/mi total, 25.5 whr/mi battery
Details:
Voltage started around 43.5-44V and quickly leveled to 42V under
load. I was dropping about a volt, but at limited current power of
est 15A, 650W. I checked impedance 2x and both were about 100
milliohms at the CA meter. Ended the ride at 40V under load.
Running at 42 V, the Opti center cadence sweet spot moved up about 10
rpm from 85 to 95. The min rpm on a new charge moved from 80 to 90
rpm. On my 2 yr old battery, I run at 78 rpm under load, and only
because it it degrading the the voltage is around 36.5V. At 42V,
plenty of voltage and power.
PROBLEM :: The controller is limiting the power/current. Bost mode
work great and is uninhibited. I see 870-950W in boost for 2-3 sec.
During steady state, the bike only want to put out 15 amps and
650-670W before i feel a phase back under increasing loading. Thus,
instead of upping the juice and giving me the speced 850W steady
state, my controller just allow limits around 670W and lets the rpms
fall as load increased. Disappointing! If I push the pedals hard and
stay in the 92-95 rpm range, current is 15 amps typ and tin the sweet
spot.
Down hill, the speed tops out at 38-39mph at 42-43V !!
It is interesting that my stock 36V opti battery will give me 18-19
amps steady state, which give more torque when riding.
The higher voltage should allow for a few more watts to get to the
motor, but the opti guys have it programmed for efficiency.
I had the exact ride a couple weeks ago and was pushing hard and had
the EXACT same average! However, battery usage was 19.6 whr/mi vs
25.5 today. I expect I am running less eff because I can't keep the
95rpm and am loading it harder. Other results have seen a 21.5 mph
average for that ride, so the new battery did give me a 1mph bump
without any extra effort over the stock 2 yr old battery.
Summary:
1. The A123 at 43V gives about the same speed performance as the
stock OPti on average speed...so far. High end speed on flats and
hills is higher. Torque on hills is LOWER.
2. The 43 V makes the cadence a little high for my preference. I
like 85 rpm centered.
3. The new pack did give me a slightly higher average power, only
because it stays flat the and stock is dropping off at 10 miles.
Average battery watts were 578 vs 480 watts typical. I expect a new
Opti battery was up there near 600W average for a ride.
4. At this time, ther eis nothing I can do to get more power out of
my Optibike. The estimate average power from the motor, running at
85% eff, is 500W. My old battery is giving me 350-400W ave during a
22 mile ride. For an 850W system, I don't understand why the steady
state is limited. It must be a limit on the operating range of the
motor??
More later..back to work.
Dan
lowco2
Aug 2, 2011, 2:16:25 PM8/2/11
to Optibike Owners Group
Back to work? Sounds like this is work!
Very cool data and results. I don't know why you are seeing that power
level, but I'm curious if you know if you are on the "low boost" or
"high boost" setting? That might impact your results over a whole ride
if you have some start-stop along the way.
--John
Very cool data and results. I don't know why you are seeing that power
level, but I'm curious if you know if you are on the "low boost" or
"high boost" setting? That might impact your results over a whole ride
if you have some start-stop along the way.
--John
Bike_On
Aug 2, 2011, 3:06:14 PM8/2/11
to Optibike Owners Group
More than you know! It makes me appreciate the work Opti did to give
an integrated BMS design.
One thing I discovered is I had to change my riding style. With
internal only and a light pack, I ride on propedal setting and often
lock the front shocks on the fly.
With the extra battery and weight, I am running full suspension. I
threw my small pack on my back, but it blocked my view from my eye
mirror when tucked on aeros. I stopped and put the pack on the front
an a front pannier. It's getting out of control.
I started with HIGH Boost. Going up a steep incline, no pedalling, I
could "bounce" the bike on the shocks and induce boost mode, which
actually could see 1100-1200W peak. High boost does allow good
acceleration. But be warned, the rpms must be high enough (ie the
current low enough) or it won't give the boost. It was below 15A for
me.
I changed to low boost part way through, which disallows that bounce
technique, but does seem to sustain the boost a little longer. The
high boost "feels" more rewarding given the capacity of the battery
and high power ability.
I suspect the power level I am seeing has likely been there since I
got the bike, which was designed to be an 800W unit. I zipped an
email to Jim Turner, a few weeks ago and asked th esame question from
my intiail ride July 9th. He suggested the current sense calibration
may have not been increased to match the 850W set point in software.
Still, the bike is not even an 800W, steady state output machine. I
have the option to gut the wires and send back over winter.
My other thought is some kind of a thermal limit in the motor, causing
a phase back. I can pull a connector pin if that is the case.
Trying to be the first to run a 960W (42V*23A) Opti. Not there yet.
Dan
> > > Summer days are about to be burned....let you all know when I can.- Hide quoted text -
an integrated BMS design.
One thing I discovered is I had to change my riding style. With
internal only and a light pack, I ride on propedal setting and often
lock the front shocks on the fly.
With the extra battery and weight, I am running full suspension. I
threw my small pack on my back, but it blocked my view from my eye
mirror when tucked on aeros. I stopped and put the pack on the front
an a front pannier. It's getting out of control.
I started with HIGH Boost. Going up a steep incline, no pedalling, I
could "bounce" the bike on the shocks and induce boost mode, which
actually could see 1100-1200W peak. High boost does allow good
acceleration. But be warned, the rpms must be high enough (ie the
current low enough) or it won't give the boost. It was below 15A for
me.
I changed to low boost part way through, which disallows that bounce
technique, but does seem to sustain the boost a little longer. The
high boost "feels" more rewarding given the capacity of the battery
and high power ability.
I suspect the power level I am seeing has likely been there since I
got the bike, which was designed to be an 800W unit. I zipped an
email to Jim Turner, a few weeks ago and asked th esame question from
my intiail ride July 9th. He suggested the current sense calibration
may have not been increased to match the 850W set point in software.
Still, the bike is not even an 800W, steady state output machine. I
have the option to gut the wires and send back over winter.
My other thought is some kind of a thermal limit in the motor, causing
a phase back. I can pull a connector pin if that is the case.
Trying to be the first to run a 960W (42V*23A) Opti. Not there yet.
Dan
lowco2
Aug 2, 2011, 4:05:39 PM8/2/11
to Optibike Owners Group
Wow, a 960 W Opti would be cool. I remember moving from my 600 to the
800, the difference was not very noticeable on the flats, but I really
could tell on the long climbs I have on my commute. That steady state
pull at higher levels will surely feel as noticeable when you get
there. Looking forward to hearing more about it....
--John
800, the difference was not very noticeable on the flats, but I really
could tell on the long climbs I have on my commute. That steady state
pull at higher levels will surely feel as noticeable when you get
there. Looking forward to hearing more about it....
--John
Bike_On
Aug 3, 2011, 12:58:04 PM8/3/11
to Optibike Owners Group
** Riding the Optibike at 42V steady **
Getting more use to the higher cadence. Running at 40-42V under loads
of 550-650 typical from battery, as seen on CA.
Ride home is faster than inbound to work. A lot of highway grade
stretched. One section is a mile downhill at about 3-4% grade. I
stayed tucked on aeros, no pedalling and maintained 36-38 mph.
I experimented switching between 42V LIFE and 36V stock lico on the
fly. Stock was charged to 41.3V unloaded and runs down as a good
slope. As expected, the 36V stock allows for amps in 18-20 range,
650-700W underload, while the 42V life like 15-16 amps and the same
power.
Average for 22.6 miles was right at 26 mph.
507 whr
22.5 whr/mi
On ride into work, I experimented with ECO mode at 42V. Very pleasant
surprise!! Bike runs a nominal 520W, 12.5 Amps, which cruises into
the low 20's. For some reason, my bike seems to run "smoother" in eco
mode, both now and with stock battery. ECO mode allowed me to get a
steady 520-55 watts and TONE DOWN the cadence to 85-90 rather than
90-100 in FAST mode. It was a more pleasant ride. On the flats, the
boost in eco worked great, getting me up to speed in upper 20's and
maintaining 34 mph downhill, no pedalling. As the gradien tincreased
on the road, and rpms started to fall, I switched back to FAST which
only boosted ss power by 100-150W.
Again, the limiting factor with the 42V operation is that power is
phased back as load increases beyong 16A or so, rather than
maintaining an elevated power (700-800 range) with more current ==
torque. One MUST gear down and spin at 95-100rpm or basically waste
power/ be less efficient as rpms fall.
Today's Ride:
23.4 miles
23.9 mph
560 whrs
23.9 whr/mi
Motor Power ave, Battery Power ave, Human power ave = all 3
esseentially the same as debut ride.
Motor: 491, 496, 485 watts for 3 rides.
Battery: 578, 584, 571 watts for 3 rides
Human: 130, 138, 131 watts ave for 3 rides. (no comments please. :)
I don't get any credit for spinning my legs at 95 rpm to match the
motor!)
> > > - Show quoted text -- Hide quoted text -
Getting more use to the higher cadence. Running at 40-42V under loads
of 550-650 typical from battery, as seen on CA.
Ride home is faster than inbound to work. A lot of highway grade
stretched. One section is a mile downhill at about 3-4% grade. I
stayed tucked on aeros, no pedalling and maintained 36-38 mph.
I experimented switching between 42V LIFE and 36V stock lico on the
fly. Stock was charged to 41.3V unloaded and runs down as a good
slope. As expected, the 36V stock allows for amps in 18-20 range,
650-700W underload, while the 42V life like 15-16 amps and the same
power.
Average for 22.6 miles was right at 26 mph.
507 whr
22.5 whr/mi
On ride into work, I experimented with ECO mode at 42V. Very pleasant
surprise!! Bike runs a nominal 520W, 12.5 Amps, which cruises into
the low 20's. For some reason, my bike seems to run "smoother" in eco
mode, both now and with stock battery. ECO mode allowed me to get a
steady 520-55 watts and TONE DOWN the cadence to 85-90 rather than
90-100 in FAST mode. It was a more pleasant ride. On the flats, the
boost in eco worked great, getting me up to speed in upper 20's and
maintaining 34 mph downhill, no pedalling. As the gradien tincreased
on the road, and rpms started to fall, I switched back to FAST which
only boosted ss power by 100-150W.
Again, the limiting factor with the 42V operation is that power is
phased back as load increases beyong 16A or so, rather than
maintaining an elevated power (700-800 range) with more current ==
torque. One MUST gear down and spin at 95-100rpm or basically waste
power/ be less efficient as rpms fall.
Today's Ride:
23.4 miles
23.9 mph
560 whrs
23.9 whr/mi
Motor Power ave, Battery Power ave, Human power ave = all 3
esseentially the same as debut ride.
Motor: 491, 496, 485 watts for 3 rides.
Battery: 578, 584, 571 watts for 3 rides
Human: 130, 138, 131 watts ave for 3 rides. (no comments please. :)
I don't get any credit for spinning my legs at 95 rpm to match the
motor!)
Bike_On
Aug 3, 2011, 1:08:32 PM8/3/11
to Optibike Owners Group
Stock Battery performance benchmark:
ECO mode:
runs at 7amps, 280W
Recent rides:
21.6 mi, 23.2 mph, 20.5 whr/mi, motor 404 W, batt 475W, human 213 W
ave.
22.6 mi, 23.7 mph, 20.2 whr/mi, 406, 478, 170
22.5 mi, 25 mph, 18.9 whr/mi, 400, 471, 210
21.5 mi, 20.3 mph, 20.9 whr/mi, 360, 425, 155
> ...
>
> read more »- Hide quoted text -
ECO mode:
runs at 7amps, 280W
Recent rides:
21.6 mi, 23.2 mph, 20.5 whr/mi, motor 404 W, batt 475W, human 213 W
ave.
22.6 mi, 23.7 mph, 20.2 whr/mi, 406, 478, 170
22.5 mi, 25 mph, 18.9 whr/mi, 400, 471, 210
21.5 mi, 20.3 mph, 20.9 whr/mi, 360, 425, 155
>
> read more »- Hide quoted text -
Bike_On
Aug 9, 2011, 8:06:19 PM8/9/11
to Optibike Owners Group
A123 performance update:
I did my fastest and shortest commute home, net elevation change about
-250ft.
I averaged 26.4 mph, with moderate effort.
My newly discovered secret is to induce boost mode repeatedly by
"popping a small wheelie" and adding a load to the wheel. I saw 30-40
amp burst for 3 second. Battery loved it and was just as strong after
22 miles, 13.8 ahr, 563 whrs.
25.6 whr/mi, 1.59 mi/ahr. This is a record high for that run and
indicative of all the boosting on the up hills.
Wattage outputs ranged from 900-1400W during boost. AFter boost,
wattage dropped to just under 700W, no matter what the cadence it
seemed. Man, I need that steady state power to bump up to 850W and
the speeds would hold.
Battery was slight warm after the ride.
D
> ...
>
> read more »
I did my fastest and shortest commute home, net elevation change about
-250ft.
I averaged 26.4 mph, with moderate effort.
My newly discovered secret is to induce boost mode repeatedly by
"popping a small wheelie" and adding a load to the wheel. I saw 30-40
amp burst for 3 second. Battery loved it and was just as strong after
22 miles, 13.8 ahr, 563 whrs.
25.6 whr/mi, 1.59 mi/ahr. This is a record high for that run and
indicative of all the boosting on the up hills.
Wattage outputs ranged from 900-1400W during boost. AFter boost,
wattage dropped to just under 700W, no matter what the cadence it
seemed. Man, I need that steady state power to bump up to 850W and
the speeds would hold.
Battery was slight warm after the ride.
D
>
> read more »
Bike_On
Aug 10, 2011, 1:10:26 PM8/10/11
to Optibike Owners Group
611 whr, 15.1 ahrs, 21.8 mi, 51:24, 25.5mph inbound today.
I was tweeking with the balance circuits last night...my loaded
voltage seemed a tad low today. I saw <40V sooner.
I was tweeking with the balance circuits last night...my loaded
voltage seemed a tad low today. I saw <40V sooner.
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