New Lipoly Pack Report: Zippy Flightmax 8000mAh x 6

[deerfencer1]

http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=16227

So the USPS truck pulls into my driveway this past Saturday morning
and the postman comes to my back door toting a bucket with a much
bruised and retaped cardboard carton inside, along with a "Received
Damaged" label. Gulp.

Despite the subpar corrugated, which barely made it, the six battery
packs inside were individually well wrapped and taped in bubblewrap--
thank goodness. The shipping gods must have been smiling down on me--
not only did the packs not look damaged, all six charged up to proper
levels after a few mad hours of splicing and crimping. Still, how hard
would it be for HobbyKing to either beef up their boxes or doublebox
their heavier overseas orders? I just don't get it. Shipping time from
Hong Kong was exactly 10 business days.

Despite the wing and a prayer landing, I now have a spanking new 30C-
rated 37V 24Ah lipoly pack almost identical to the True RC pack I put
together two years ago--at less than half the price! ($520 vs $1250
plus wiring/connectors)

The virgin run on the packs this past Saturday put a big fat grin on
my face as I saw 1500W+ bursts up the first short steep hill with amps
as high as 38-39A, the highest running numbers I've seen on old Uma
(S750X) ever.

Max sag? Would you believe .7V? Yup, again the best I've seen and
about 40% less sag than the True RC's when new. Lipoly chemistry
continues to get better by the day IMO.

Other stats: after an hour of hill riding I still saw max amp readings
of 30+ at full throttle, and consistent wattage highs around 1140W.
Performance-wise there is a nice burst of high power 5-10 minutes out
of the gate, then a very steady plateau of slightly reduced power for
the rest of the ride. Best of all, the packs were completely cool to
the touch at ride's end! This bodes well for those occasional weekend
rides when I try to cop a lunch-time charge on the road.

I averaged about 1.4 miles/Ah with avg speeds of around 22 mph. And
given my annual winter fat gain, I'm more than pleased that these
packs can help juice me up Quaker Hill at 18mph+.

I'm determined to try to baby these packs as far as not overcharging
or overdischarging them, something I wasn't that careful about with
the last pack, which died with under 200 cycles on it. At some point
I'd love to get one more pair of these pups to allow for 2-hour
weekend rides without fear of running the packs empty.

Here are the guidelines I keep reading from some of the more
experienced engineer/enthusiasts at ES re manual BMS treatment of
lipoly:

Max charge level: around 41.4-41.7V
Max discharge level: about 80% of battery capacity (in this case about
19Ah = 80% of 24Ah)

I'm sure there will be occasional rides where I go slightly over 19Ah
but I am determined not to empty the packs completely. More reports as
the riding season progresses.

LH

[Joe]

Impressive!

Larry, you mentioned this hobbyking set is almost identical to your last True RC battery pack set. Were they both rated 24Ah? Besides the new ones having much less V sag, any other significant differences (ie size, weight) in 2 years development that you notice?

[deerfencer1]

Hi Joe,

Yes both uberpacks were composed of (6) 18.5V 8000mAh bricks wired
first in series, then hooked in parallel to a 3:1 wiring harness I
rigged on Uma, so 24aH total capacity.

The main difference between the True RC and the Zippys is the C rating
(10C vs 30C), which I assume accounts for the big improvements in
resistance and running temperature. To find the packs almost stone
cold after an hour's ride was a beautiful thing!

Size appears almost identical. Weight? The Zippys may actually be just
a touch heavier than the True RCs @ 1054 grams vs 930 grams

http://home.comcast.net/%7Etruerc/ready_pack/ready_packs.htm

LH

[Bike_on]

Larry,

Big congrats on the new lithiums. It's all about the battery, is it
not?

So the pack weight is about 14lbs total for 24Ahrs?

School me on the discharge rule of 80%. Why not go by a BMS
thatlimits the cell voltage as sufficient?

I ask because I am getting a new lifepo pack and need to plan the
limits.

Is li-poly more sensitive than lifepo when it comes to capacity
discharge, or is lithium the same?

What was the current at your 0.7V sag point?
Dan

> > LH- Hide quoted text -
>
> - Show quoted text -

[Joe]

Larry,
I got a good feeling that these are better suited at 30C for the kind of torture your hills and need for speed put on batteries. Especially long down hill regen. These might be able to eat that right up.
Good luck with them!
Joe

[deerfencer1]

Thanks guys!

Dan, that 80% capacity reserve rule is just one I keep seeing posted
at ES in regards to extended lithium life in general, and it's very
simple to monitor and manage that with a CycleAnalyst, which I
consider an absolute must-have to forgo a BMS. I've seen too many
glitches with BMS's in general to like them, so given the choice I
prefer to ride (and charge) naked with care.

Don't know if lipoly and lifepo play by different rules but would be
surprised it they weren't close to the same.

Current @ .7 sag varies from 1400W+ the first 10 minutes to 1100W an
hour later (full throttle readings).

Joe, I had the exact same thoughts re regen barreling down Kirby Hill
this afternoon where I briefly saw 52 mph and 32A+ regen.

Interestingly, the e-dirt bike I bought years ago came with an
industrial type heavy-duty lead acid battery charger rated 22A and
built like a brick. I've read at ES that you can use (again with great
care and supervision outside) SLA chargers for lipolys with monitoring
and intend to post a query there tonight re possible use of this
charger on these packs hooked in parallel. 22A/3 subpacks = 7A charge
per pack, which is under 1C. Unless I'm missing something I might well
be able to charge the full pack in one shot to 80% capacity in under
an hour!

Here's the model with a good description. I invite any knowledgeable
parties (hint hint, Doug and Jeff) to comment on the advisibility of
charging this way. The new Zippy packs do advertise high charge rates
right on them, so I'm assuming <1C should be safe.

http://www.batterygiant.com/Battery-Chargers/Product/MLT22036


Larry

[deerfencer1]

Just a note to myself that the CA showed 226 cycles to date when I
first hooked up the new lipolys.

Separately, two revisions:

1) I looked more closely and the new packs are about an inch longer
than the now defunct True RCs (and as reported earlier 100+ grams
heavier). Width and depth are about the same.

2) Average efficiency/range to date is closer to 1.3 miles per Ah than
the previously reported 1.4 miles.

I did a nice one hour 20+ mile hill ride today that felt great. My
body feels like it's coming out of a (too) long winter hibernation and
after some initial discomfort the first two rides I'm starting to feel
a lot better physically. Amazing how the body responds to some
positive psychological input in very short order.

LH

[Bike_on]

Larry,

what is the top speed on a flat stretch, WOT, no wind with the TFX?

Post some pics?

Dan

[Ambrose Liao]

I would also love some pix of the new pack on Uma.

Thanks,

Ambrose

[deerfencer1]

I'll post some pics shortly.

Haven't done a WOT speed test on a pure flat but will soon.

I do know that on yesterday's ride I saw 31-33 mph on a long flattish
stretch with a slight downhill pitch with no pedaling at just 650W or
so. I've found that on these types of extended fast stretches of road
I'm almost better off NOT pedaling and focusing on aerodynamics,
namely staying on my aerobars as low as possible and letting the motor
do the work.

This is also the perfect application for my self-made sticky Magura
twist throttle. I've jammed enough electrical tape between the fixed
mount and moving throttle that the spring return is retarded and the
throttle pretty much stays where I put it until I decide to move it
again. Crude but effective. It may sound a bit risky but a tap on the
brakes cuts the power instantly and I've gotten very comfortable with
it.

Advantage over using cruise control is no chance of potentially
lurching into regen (which WILL happen if you build momentum),
throwing the bike off balance, which IMO is much riskier than my
"manual" throttle method. On TFs (and probably E+s), regen is
automatically overriden when the throttle is engaged. About the ONLY
time I use the factory cruise control is for a throttle lock on long
climbs. The manual throttle has a tendency to slip a bit over time
from road vibration but is great for smooth flat stretches at less
than full power.

LH

[deerfencer1]

On May 4, 11:45 am, Bike_on <therowe...@verizon.net> wrote:

> Larry,
>
> what is the top speed on a flat stretch, WOT, no wind with the TFX?
>

Top speed on the flats with 240lb rider on the aerobars full throttle
no pedaling appears to be somewhere in the 30-33.8mph range. I did two
separate brief tests yesterday about 25 minutes out and with the
wattage reading around 1200W. There was a slight breeze so I'll repeat
the test this weekend if possible.

Four one-hour rides on the new lipolys to date and so far they're
performing flawlessly with the subpacks in excellent balance at ride's
end. Still can't get over how cool they stay and am hoping this will
lead to a long service life.

Performance-wise, other than slightly higher reading off a fresh
charge, these packs are extremely similar to my previous True RC
lipolys in their discharge curve and output. Interestingly, they even
seem to have the same sweet spots after 30-40 minute hour run
time--1130W is a number I remember seeing a LOT of on the old packs
and now these as well on climbs at full throttle. To date I haven't
run the packs below 36.5V loaded, so about 37.5V unloaded.

I initially saw higher sag numbers yesterday up the first long 4-mile
climb and assume the subpacks were not in balance off the charger. By
midpoint on the ride, though, things seemed to firm up and the sag
returned to that .7V level I first observed. Based on what I've read,
I'm expecting it to take a couple dozen cycles for the packs to truly
get in sync with each other and am trying to be careful not to even
come close to depleting them before then by keeping a minimum of 6 Ah
in reserve, and loaded voltage above 36V. This is not hard to do on my
typical one hour local rides.

LH

[deerfencer1]

Long (2 hours+) enjoyable brisk touring ride up to Kent CT and back
this afternoon with a 50-minute root beer float/recharge break on Kent
Green where I was able to cop around 6--7 extra Ahs at a public outlet
with my three little 3A li-on chargers hooked up to the (3) 8 Ah
subpacks.

Packs behaved beautifully and were mildly warm at ride's end;
remarkably, 5-10 minutes later they were almost cool to the touch.
Loop was a typical mix of semi-flats and rolling hills with the return
ride much hillier than the route out--but with a nice tailwind.

A lunch or snack break recharge is key to these longer weekend rides,
and this is the first time I've employed all three mini-chargers,
which combined enable 9AHs per hour. So theoretically if I took a long
2-hour lunch break I could double my normal range, which is 25-30
miles. Today's ride was over 40 miles and about as far as I want to go
until my fitness level increases.

Packs never dipped below 36V and I was still able to pull 1100-1160W
assist up the last steep hill at mile 39. All in all a great example
of what lipoly is capable of. And specifically for my personal
purposes I now know one more subpack would enable this kind of ride
range without a recharge.

SV 41.9V
EV 36.7V
Riding time: 2:08
41.54 miles
26.36 Ahs
1.575 miles/Ah
1047 Watt Hours
3.8% regen or 1.01 Ah
36.1V min
39.3A max


LH

[knoxie]

Hey Larry

Havent checked in for a while been so busy on ES playing with my Gopro
and posting videos (just like the old days) ha ha, great news on the
packs, they sound like the ticket! I have had mine for a year now and
they are as good as they were from new, I charge to 4.1V using my
lithium ion setting on the charger and also never drop below 3.4V, the
Turngiys are also notorious for having a bit more capacity than the
label suggests but dont rely on that esp without a BMS.

I dont use a BMS either just watt meter and cell buzzers, works for me
just fine, I can charge my pack in an hour, I have a very nice 40A DC
supply and a 4 channel charger that will charge and balance each pack
in an hour if I need to, I can also get the charger and supply in my
back pack if I really need the extra range, however I tend to just
peddle more.

So glad that the ride has been spruced up by the new cells and that
the costs have come down, the great thing is I can see the costs
coming down even more and the capacity going up! go on treat yourself
to the extra packs!! you only live once :-)

Oh the HK shipping thing is quite normal, my box looked like a right
state however the cells were all fine, others have had issues but the
packs are a lot tougher than people think, some people on the ES
forums would rip strips off HK in public about the packing of the
cells them tape the same packs to the downtube of their bikes flicking
mud and rocks at them all day long ha ha.

Looking forward to hearing more ride reports and seeing some pictures,
heck and why not some video cmon Larry get the camera out!!

Knoxie

[deerfencer1]

Hi Knoxie,

Thanks for checking in.

Don't know about video but I've been thinking I'm way overdue for some
good still shots of my favorite spots on my rides. May have to borrow
my daughter's camera--she's got a pretty high quality one.

The new packs certainly look professionally produced and I was
ecstatic that the six of them all seem fine after the shaky transit.
Between the <1V sag and their very cool running temperature, they look
to be keepers!

Regards,

Larry

[Bike_on]

Larry,

Good weather in the East. How are the rides?

Say, on your meter, what is the steady state current for a TFX at WOT
on flats?

Dan

[deerfencer1]

Dan,

Gorgeous weather here in NY this week but I've been working (for a
change) and rides may be limited to weekends for now, which is fine.

Will test current readings at WOT and get back to you but I'm assuming
they'll be identical to full climbing numbers, namely 1100-1400W
depending on what part of the ride.

LH

[Bike_on]

Larry,

So are these pups better, worst or the same as the true RCs? Can you
remeber? :)

Dan

On May 3, 2:55 pm, deerfencer1 <deerfenc...@aol.com> wrote:

[deerfencer1]

So far I'd say the Zippys are better, if only for the cooler
perfomance and reduced voltage sag. Power-wise they feel VERY similar.
The Zippys also look professionally manufactured, not that the True
RC's didn't, but both are far slicker than the duct-taped liFepo
abortions you see being sold on eBay.

I'm fairly certain I'll be buying 4 more subpacks for my wife to ride--
and for me to take on those long weekend rides I love. At this
pricepoint these packs are very hard to resist.

Larry

[deerfencer1]

Impressive performance from the Zippys today on a 43+ mile ride at
almost 23 mph average speed. One 45-minute stop in Kent for a recharge
and root beer float after the first hour, then a second one hour break
about 16 miles later when the weather turned nasty and torrential
showers moved in.

Luckily I was close to a town park about 8 miles north of home and was
able to sit out the rain in a large picnic shelter that also had
working 115V outlets, so popped the chargers back on the packs again
for a fast ride home when the rain finally ceased.

Gobbled a LOT of Ahs--I think around 35--which is I'm sure a personal
record on a single ride for me. Checked the sag towards the end of the
ride and it actually read -.6V up the last hill, which is an even
better reading than I'd been getting on previous rides (.7-.8V)!
Remarkable.

I started the ride with the packs @ 42.3V, higher than I'm planning on
charging them most of the time, but I was curious to see what kind of
difference that extra volt makes. Answer: a LOT. Saw burst readings of
1560W several times on the first hill or two, then 1400-1450W range
for the rest of the 3.5 mile climb up Quaker Hill. So these packs are
absolutely more powerful than the True RCs, to the tune of about 10%.
I'm guessing the Zippys' high C rating and minimal sag are
responsible.

The bottom line is (at least for me on most rides) that if you have
more climbing assist power available, you'll use it; therefore overall
efficiency drops but average speed noticeably increases. These are
very powerful cells and I only hope they last a few seasons as they
are definitely the best I've ridden. It will be interesting to see
what kind of sag readings I get after a few dozen rides when the packs
become even better balanced.

LH

[deerfencer1]

Here's a much more detailed real world ride report from yesterday's
excursion detailing the weather and sights along the way that I just
posted on Facebook:

Action-packed 43-mile e-ride yesterday up to Kent, CT and back. Got
briefly paced/spooked by two whitetails who decided to run parallel to
me up Quaker Hill off the shoulder of the road @ 20 mph+. This was
just a mile or so from the spot where another Pawlingite, Jeff
Coursen, got killed on his motorcycle when a deer bolted out and hit
him a year or two ago. I quickly crossed over to the left lane for
added buffer before a small truck came along and got the deer moving
away from the road.

Nice great blue heron sighting on Schaghticoke Road above Bulls Bridge
about 15 miles later, where the waterfalls off the granite ledges were
roaring. Of course when I stopped and circled back to check it out
more closely, Mr. Blue immediately took off again.

http://farm4.static.flickr.com/3398/3342669093_2163002f6b.jpg

Several rowing teams from the Kent School were out practicing on the
Housatonic, the coaches traveling alongside in some very quiet motor
boats. Must bring a decent camera next time to document this area, one
of my favorites.

Root beer float and recharge break a few minutes later in downtown
Kent, which was surprisingly quiet given the beautiful weather--at
least until some very ominous clouds started to gather in the
northeast skies. Weather still looked mostly sunny and bright towards
NY, though, so I put the bike and body in turbo mode (1300W+ at full-
tilt boogie) and raced due west on RT 341 into the rolling hills of
Amenia and Dover, where the temperatures suddenly dropped and a few
fat drops of rain came spattering down. Under ever darkening skies the
winds picked up dramatically and shifted out of the E/SE, in a couple
spots almost blowing me off the road on the ridges--and this on an 80
lb bike with a 200+ lb rider!

Barely made it to the picnic shelter @ Boyce Park in Wingdale before
the heavens opened. An hour later the rains ceased and I had a quick
but soggy ride home via West Dover Road. Worst were the mayflies,
which have been swarming in clusters on the road lately, making my
face feel like a bug grille. Pretty gross. The birds love them though--
I came upon a couple small groups of them just hanging on the blacktop
chowing down on the buggers.

http://www.aquatax.ca/images/mayflyAdult01.jpg

All in all a fairly dramatic and exhilirating ride. Average speed was
close to 23 mph, very fast for this length of ride (43 miles), and my
new lithium battery packs performed like champs.

LH

[deerfencer1]

Just back from a fairly fast local one hour hill ride over to Sherman
town green and back, about 20 miles. The packs seem to be getting even
more powerful, but a lot of that has to do with the fact that I've
given up on the idea of limiting the charge to 41.4V and am letting
them fully charge to 42.6V, which seems to be the max those little 3A
lipoly chargers output.

Why?

1) It's just too much trouble trying to monitor them manually since
I'm charging three subpacks on three chargers at a time, and

2) more significantly the extra power and range I'm getting with a
topped-off charge is substantial and not to be dismissed: today I
briefly saw burst readings of 1600W+ up the first hill, the highest
I've ever seen. And even after close to an hour's hard running time I
was getting max assist @ WOT (wide-open throttle) readings in the
1250W range, which is impressive indeed. Plus, I had all sorts of
spare juice left after the ride to boot. I've decided that at this
price I'll sacrifice some cycle life for the extra miles enabled per
ride.

The one thing I remain determined NOT to do is to over discharge them,
and so far I have not run them below 36V fully loaded. Today's ride
ended somewhere around 37.7V unloaded.

LH

P.S. Side note: On an earlier ride last weekend on a pack that read
42.3V out of the gate I saw a max burst reading on the CA of over 62A
after the first steep hill! I've never seen amp readings in the 60's
before and always thought the Wavecrest controller software limited
input to the motor to 60A--apparently not true.

[deerfencer1]

High speed joy ride today that shows how good these packs are. I was
heavy on the throttle throughout the first 11 miles:

* 22-23 mph average up a timed 2 mile graduated hill off a fresh
charge with max pedaling. This is a hill I usually average about 19-20
mph up.

* 29 mph average speed for first 11 miles of mixed hills and rolling
terrain, again with vigorous pedaling, and screamed across some fast
flats @ 36 mph. I then took it down a notch as I was headed into a
trafficked area but still attained

* 26 mph over 19 miles, even with a motor power drawdown around mile
13, which reduced assist to around 700W average.

Once I get my new aux packs I'll test how many miles I can cover in a
fast hour's ride. Efficiency was around 1.2 miles per Ah, so even at
full-tilt boogie I ought to have 40-mile range--increasing to 55 miles
+ with more conservative riding @ 1.6 miles/Ah.

LH

> > > > > > or overdischarging them, something I wasn't that careful about...
>
> read more »

[deerfencer1]

Fast fun 18-miler today over mixed blacktop (first 12 miles) and
packed dirt. CT did a major repaving of Route 37 in Sherman last year
and now there's probably more than 10 miles of near perfect blacktop
on routes I ride regularly there, which makes the going idyllic,
especially when traffic is light (most of the time). In fact once I
get beyond the first fairly rough mile out of my driveway, the next
1/2 hour is all on superbly paved country roads, hilly, windy, and
very scenic. I'm a lucky dog indeed to have all this in my backyard.
There are a lot of fast rolling stretches where I can now almost
completely relax on my aerobars at around half-power, get in a tuck,
and cruise in the 32-36 mph range. Heaven. I kept ahead of a monster
logging truck for a few miles today on Rt 55 in Wingdale averaging
about 35 mph over one stretch of road just before my dirt road turn-
off, which I was able to duck down before he passed.

Batteries continue to perform very impressively. On a side note, I've
noticed that the heat-generated motor power drawdowns are coming
around 35 minutes into a hard ride, which is 5-10 minutes sooner than
I saw on my old packs. Makes perfect sense since the motor is running
at higher voltages (and I assume higher temps) by close to 10% due to
the minimal sag of the new Flightmaxes.

Given that I'm usually about ready at that point in my rides to turn
things down a notch anyway, the reduced assist doesn't bother me at
all, especially since it also results in expanded range and is kinder
to the packs as they get drawn down. I typically see amps drop to the
24-25A range, or about 900W+ (almost as if Turbo has been turned off),
then if the motor continues to overheat, a second drop to the 750W
range. The only time it's an issue is on steep climbs towards the end
of a ride, something I try not to do as a practice anyway. (One of the
beauties of sports riding is that you can usually tailor/design your
routes so that the most vigorous portions come when the batteries and
rider are fresh, i.e. during the first 1/2 hour or so.)

LH

> > > > > > > my face as I saw 1500W+ bursts up the first short steep...
>
> read more »

[deerfencer1]

Did my annual tri-state (CT/MA/NY) ride today up in the NW corner of
CT (Salisbury) over mixed dirt and blacktop and was very impressed
with the new packs' performance. 8-mile climb out of the gate
averaging close to 16 mph over some seriously steep, rough grades in
which I saw 1350-1450W max assist for about 20 minutes. I clearly
remember panting heavily the last time I rode this grade a year ago--
not the case today.

Gobbled Ahs like nobody's business on the climb-about 8Ahs for the
first 6 miles--but made it up on the return ride over smooth blacktop,
flat to favorable grades, and a sweet tailwind on the return ride
through NY (Rudd Pond area) where I averaged about 2.2 miles/Ah.
Overall average speed was 19 mph, not bad considering I climbed one of
the steeper mtns in MA (Mt Riga/Washington).

Was gladdened to see decent crowds at the state parks in the area,
especially Rudd, which was closed last year due to budgetary problems.
In fact the park @ Copake (NY) was busy and sporting a new park
headquarters building, possibly part of the Obama stimulus package.

That said the roads themselves were remarkably quiet and the weather
glorious. One of the nicer rides I've done in a long time with
Maryland crab cakes for lunch @ the funky deli/general store in Copake
Falls.

Such a sweet area; seriously considering retiring somewhere up in that
corner of the world in a few years.

LH

> > > > > become even...
>
> read more »

[Bike_on]

Hey Larry,

Glad to see you are enjoying the new lithiums and your annual tri
state ride.

Since the CA post is whr/mi, any change you could update your post
below to specify whr/mi under the different conditions?

I know your like mi/ahr, which is easier to predict range. But the
Whr/mi give better comparison numbers and granularity.

Danka,
Dan

On May 29, 4:38 pm, deerfencer1 <deerfenc...@aol.com> wrote:

> > > > > > > my face as I saw 1500W+ bursts up the first short steep- Hide quoted text -
>
> - Show quoted text -...
>
> read more »

[deerfencer1]

Granularity??? Qu'est-que c'est?

LH

> ...
>
> read more »

[bMF]

+avec moi.

meetinx heemeens resolution.
like fahrenheit has finer integer increments than celsius which has to
resort to (shudder) extra digit decimal points.

really, there's absolutely no difference in granularity if that's what
he's driving at.
either way it expresses the identical quantity be it energy or
temperature.

_ ,
_\=\_
(o)+(o)

[deerfencer1]

34+ mile mellow touring ride up to Kent CT and back yesterday in 85-90
degree weather, actually much milder and less humid than it's been all
week here in SE NY. No recharge necessary as I took a less hillier
loop than usual and was very frugal with the power going out, easily
averaging 2 miles per Ah over the first 24 miles.

Had plenty of juice in the tank to do the final return stretch on dirt
backroads through the woods past Quaker Lake with lots of shade and
zero traffic. Ended the ride around 37.2V having used well over 800
watt hours. Also, beacause of my reduced pace I saw zero thermal power
brownouts from the WC motor controller. Packs have been performing
flawlessly and were just mildly warm at ride's end.

LH

On Jul 11, 6:02 pm, Bike_on <therowe...@verizon.net> wrote:

> ...
>
> read more »

[deerfencer1]

It's been about five months since I've been running these new lipos
and they continue to impress. Weather and business have curtailed my
usual summer mileage this year but I believe I've put the packs
through about 30 cycles to date.

They're still charging fully--all the way up to 42.7V if I leave them
on the charger overnight--and on my most recent ride this weekend the
packs gave me 23Ah with 36.5V left showing on the CA at ride's end, so
full capacity.

The coolest thing is seeing 1500W up the first steep hill off a fresh
charge, though, and I've even seen (momentary) burst readings of over
1900W--yowsuh! And an hour later I'm still getting over 1100W assist,
so I believe I already have the new Opti beat raw power-wise <g>.

The only downside I can see to them is that when run full-out in X-
mode, the motor will go into
voltage-drawdown mode sooner than with a lower-powered battery due to
momentary overheating. IOW the more powerful packs push the motor
harder, which of course produces more heat. That said, it's easy
enough to control the power draw to minimize this, especially on
longer, more mellow rides. Awfully nice to have that ability to goose
it in certain situations, though.

In short, I couldn't be happier with these packs' performance to date,
and am hoping to get several seasons out of them.

LH

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[Baris Eris]

Hi there,

 

This is a great thread. I have a Tidalforce S-750 with dying front battery (goes about 3-4 miles tops and cuts out on hills). I like what I'm reading on this forum and want to fix the battery situation for this bike. Here's what I gathered:

1. I need to enable B battery using the jumper as described here: http://ebikerider.blogspot.com/2012/03/how-to-use-external-battery-pack-with.html 

2. I need to buy batteries. Well... Seems like I need 6 of these: http://www.hobbyking.com/hobbyking/store/__16227__ZIPPY_Flightmax_8000mAh_5S1P_30C.html 

 

That much is OK; but I need help on the following:

3. What kind of charger do I need to use? Specific links?

4. Where/how should I plug the new packs? Does anyone have a wiring diagram/pics?

5. What are the operational details? For example:

 

Do the Tidarforce controller continue to work, and would I simply use "B" battery button to "activate"?

When I need to charge, will I unplug the whole pack and then connect to charger? Considering there are 6 of these batteries, am I to separately handle charging them or can it be done in parallel somehow?

Are there special charger considerations? Like monitor voltage etc?

 

I'd like to make the jump but need a bit of hand holding. I appreciate if you could clarify these points.

 

Thanks,

 

Baris.

[Joe]

Hi Baris,
I'll answer some of your questions by explaining what I know about how the TidalForce system works -
As long as your A battery remains connected to the handlebar controller and has some power you don't absolutely have to install the non-wavecrest jumper into the controller. That jumper does not "enable a B battery" it enables using a non-Wavecrest (Tidalforce manufacturer) battery without a Wavecrest battery connected at all. IE the wavecrest battery management system (BMS) is normally integral to the function of the motor and "tells it" to turn on. The jumper tells the motor "OK to turn ON" always. So once the jumper is connected all you have to do is apply a ~36V DC power source to the motor and it will turn on.
The key switch and the buttons on the handlebar controller are specific to controlling the wavecrest battery (BMS). They will continue to work as normal on a wavecrest (usually the front hub) battery to turn it on and off even after the jumper is installed but if there is a non wavecrest battery connected the motor will immediately "turn on" and be usable since that power is independent of the switch in the wavecrest battery.
So to answer your questions 4 and 5 you typically plug the non wavecrest battery into the B battery power plug usually found near the base of the seat tube (but you could also use the A plug at the front hub if want.) The bike will turn on as soonn as the power is connected if the jumper is installed. The buttons and key on the controller only control wavecrest batteries. Also note that the state of charge LEDs only work with wavecrest batteries.
As far as wiring packs - you need to wind up feeding about 36V to the bike. The standard wavecrest battery voltage ranges from about 42V at full charge down to about 36V when "empty". The motor will not turn on if the voltages are far outside of this range, and I know it will shut off if it drops below somewhere around 32V.
Although folks that have posted here often hook these batteries up with several Li packs in parallel I should point out that if one pack fails in a way causing a short (or if any accident causes a short) the batteries could potentially be very dangerous since you're talking about a lot of stored energy in a small package close to your body. Li explosions and flames are not unheard of. There are ways of installing safety power diodes and fuses to reduce or eliminate the sudden discharge of energy due to shorting but that's beyond my expertise.
Legal disclaimer - Proceed at your own risk.
FYI I believe LEVT can refurbish the original equipment with fresh new NiMH cells that will restore the bike to better than new condition.
Best,
Joe

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[Ambrose Liao]

LiPO packs are to be approached cautiously. I've heard of too many fires recently where major damage has occurred to people's homes/garages when they didn't take their usual precautions In charging their packs. I try to stay away from such a volatile chemistry. I have not heard of any fires from NiMH or LiFePO4 batteries.

If you do decide to go that route, then I would highly recommend a top quality balance charger. There are too many to choose from to name one. The balance function is critical to keeping and maintaining a healthy pack. LiPO packs are usually made up of a series of Pouch cells that are put in series to achieve the required voltage. If a pouch goes out of balance with the others and a non-balancing charger is used, the pack will be stressed and the possibility of malfipunction increases. A balance charger monitors each cell during the charge cycle. A high quality BMS (battery management system) is also required.

The increased time it takes to maintain and monitor a LiPO pack takes away from the pleasure of just taking off with your bike for a ride.

Just my 2 cents...

Ambrose

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