I have 2qty F cell nimh packs. 13AH ea. Hardly worth the trouble IMO. You will have serious balance issues with 20 series cells and unless you use them regularly they won't compare to SLA AH range. They lose charge just sitting for day or two. Then if not used regularly they just don't avheive max range. Now stuck carrying more nimh batteries than original SLA. Result = no weight savings.
IMO start with lead and save for lithium.
I just bought a Schwinn Izip with the SLA battery on sale at Canadian Tire for $349.95. I'm just looking at batteries and they are more expensive than the whole bike I bought. I love my NiMH batteries in my camera, I have the same set since 2004 and just keep recharging them, they seem to last forever.
If I take lets say 30 D cell NiMH batteries, but do not weld them, they will be press fit together with springs. This may cause corrosion but I will be able to take the batteries out and charge in pairs (4 at a time), and clean the contacts after each use. There may be a gel for the contacts that will stop corrosion also. With 30 D cells I will be at 36 volt, and should be able to avoid draining them deep enough to get into the balance issues. Any thoughts on this?
sure, give it a try! Remember though your camera pack probably had 6-8 cells in series. Far cry from 20-30. Your camera probably needs well under an Amp too.
Getting 20-25A running through a string that's shoved together doesn't sound very practical to me either.
I've been there done that with $400 worth of nimh batteries - start with SLA - save for lithium.
Tell me if my calculations are correct.
(20) Tenergy D Cell 10,000 mAh batteries
Volts= 24 Volt
Ah= 20 Ah (this one I'm not sure of, take 10,000/1000=10/10=1*20= 20Ah ????????)
(30) Energizer D Cell 2500 mAh batteries
volts= 36 Volt
Ah= 7.5 Ah (not sure about this either, take 2500/1000=2.5/10=0.25*30= 7.25 Ah ??????)
no - 20 series cells would be 10AH
Energizer 30 series cells 2.5AH
Without series/parallel configurations AH will be the single cell capacity.
Plus, I bet you have no idea how much current can be demanded from that battery.
I'm gonna repeat my very EXPERIENCED advice one last time - your idea is not the battery pack for an eBike. Dig?
Thanks, I have lots of time to figure out which way to go. I'm currently having a good old time with the standard SLA battery included. Plenty of power, maybe because it is new. Here's me zipping along.
Firefly secures additional funding for further commercialization in the 4th quarter of 2008. Hopefully, we'll see some of this advanced SLA technology available for EV applications like bicycles soon.
PEORIA, Ill., Jun 10, 2008 (BUSINESS WIRE) -- Firefly Energy Inc., ( www.fireflyenergy.com), the Peoria, Illinois-based company developing a portfolio of next-generation lead-acid battery technologies, today announced it completed a $15 million Series C equity round of financing led by a strategic group of Clean-Tech investors.
Firefly Energy will use its new capital to accelerate into volume production for first-generation products in commercial and military markets. The funding will also be used to support expanded product development, research and product awareness in new markets.
Firefly Energy Inc. ("Firefly") is a Peoria, Illinois-based battery technology company developing a portfolio of lead-acid battery technologies and products to enhance battery performance within major portions of the worldwide battery marketplace, now estimated at $30 billion in annual sales. The company's first applied technology is a microcell foam-based battery technology, which can deliver a unique combination of high performance, extremely low weight and low cost, all within a battery which unleashes the full power potential of lead acid chemistry while overcoming its historical performance drawbacks. Firefly's battery products and their patented microcell technology deliver to battery markets a level of performance achieved with advanced battery chemistries (Nickel Metal Hydride and Lithium) but at one-fifth the cost. Microcell foam battery products can be manufactured as well as recycled within the existing lead acid battery industry's vast infrastructure. Firefly is backed by multi-billion dollar product companies such as Caterpillar ( www.cat.com)(NYSE:CAT), BAE Systems ( www.baesystems.com) (London Stock Exchange over the counter symbol:BAESY), and Husqvarna ( www.husqvarna.com Other OTC:HSQVY.PK). Additional investors include Chicago-area Venture Capital firm KB Partners ( www.kbpartners.com), Quercus Trust, Khosla Ventures ( www.khoslaventures.com), Infield Capital, and the Illinois Finance Authority. SOURCE: Firefly Energy Inc.
Extracted from MarketWatch article ...
[QUOTE=tpreitzel;7191291]Firefly secures additional funding for further commercialization in the 4th quarter of 2008. Hopefully, we'll see some of this advanced SLA technology available for EV applications like bicycles soon.
tpreitzel, nice lead, thanks. In looking at their web page it looks as if things like bicycles are a few years away. But it's good to know they are working toward solving our problems.
if your in canada you can get 20v limn 6ah batteries at canadiantire for 109 each
i'm currently running 2 in my stock bat holder on my izip
many others are using them with great success
fully charged they are 21v each
each bat will pull 31a
are 5 cell
i was running 3 12v 12a
now higher volts @42 v 40 for sla
each bat is 2.76 pounds
i took off 24lbs
charge time from lvc(15v) is 3h
nice bats 1 year warrenty
can be run in series and parallel
I am Danny from China Toppower Battery Company .
We produce high quality LiFePO4 battery . A lot of kinds of
LiFePO4 single cells and high capacity packs are available here such
18650 1000mAh 1200mAh 1600mAh
26650 2000mAh 2400mAh 3000mAh
42120 6000mAh 7000mAh 8000mAh
24V 10Ah 20Ah 30Ah
36V 10Ah 20Ah 30Ah 40Ah
48v 10Ah 20Ah 30Ah 40Ah
Merida PC550 using NIMH battery pack
OK, I just got one of these at an estate sale. It seems quite new, no tire wear, and so on. It rides great, but needs a battery pack. I got about 2 miles on my first try (but I hadn't charged it, that was with whatever charge was left when I purchased it.
I got 2.25 miles out of it on my first real test today, and am recharging to see if I can do better tomorrow.
I was pretty much pedaling all the time, but I can feel it assist me, I was riding in a flat area, and I'm not an experienced cyclist, and I'm not young and strong. It seems to stop assisting when a certain tempo is reached, and after reading everything I could find on it I believe this is how it is supposed to work.
I'm pretty happy with the bike, and I plan to use it to go to the local stores and library. I'll bring back groceries, no more than the thing can handle (considering my none to small rear is riding, too). No heavy commuting, just want to be out of the car and exercising as much as I can.
So, I need a new battery pack, and options seem limited. I'm not likely to convert, revert or subvert <g>, I just want to buy a battery.
I've checked a lot of sources suggested in various forums, with no success. Any ideas?
Where did the title go
So where did my title go?????
The bike is a Merida PC550. :)
Granny sorry that was a scooter. Try this http://largoscooters.com/merida.html they formerly sold Merida bikes, may help.
I kinda think that this might belong in the electronics thread, but it is specific to battery technology so I will post it here first.
Here's a charger chip for a single cell lithium ion battery. LM3621. It might prove useful for anyone that wants to mess around with building their own lithium ion power pack.
if you go to bulk battery suppliers, they will sell you multicell charger board that are more practical than designing a charger curcuit from a small chip like this. but for what it's worth, here it is!
i have been running 48 volt sla batteries, with a 12 ah rating. i noticed my low voltage light comes on and the bike starts cutting out after only using 5.25 a/h (as per a watts up meter). Is this normal or do i have a battery problem? The batteries are about 3 mo. old.
50C / mile - same as my 3/4 ton pickup truck
based on $450 for a new battery for my Ezee Torq I figure the cost of riding the bike at about .50 / mile.
Any thoughts here?
My order just came in this afternoon. Wuhoo!
For my Schwinn Izip, I picked up 4 yardworks batteries, and 2 chargers so I can leave one of the chargers at work.
Just a quick question, I have 2 schwinn battery cases, but instead of putting 2 yw in each case....has anyone tried anything different?
for example. will the 4 batteries sit in the frame of my bike, if I stripp the cases off of them, and build a custom enclosure?
Battery and motor info
The battery cost per kwhr/cycle ( cycle in as number uses you get before having to replace batteries)
is still very high. For most users the cost for the battery replacement is far morethan the cost of the electricity used to recharge the batteries. I am trying to develop a network batttery exchange stations where you just drop of your old battery and grab aftreshly charged one. To do that we need a standard battery module . Although I did have ecars in mind when I started this project ebikes are probably a more significant user group, since ebikes are already trying to minimize their carbon footprint. Here's the initial spec. If you are interested her's the uRL to my original article:
I'd like comments:
Battery Pack Specification
BPS- RACH-1007-REV A
Module for EV use. Modular packaging for easy removal for off vehicle low rate charging/conditioning.
Voltage 45-55 , nominal 50 volts.
Discharge current Max current 100 A 5 seconds, 50 A 20 seconds, 30 A continuous, 20 A 1 hour.
Charge acceptance as high as possible for regenerative braking.
Series and/or parallel connections to provide 400 volt systems
BMS required for each pack.
Connector: Andersen style or equal
Dimensions:17" x 7.5" x 4" 430mm x 190mm x 100mm
Weight:Less than 20 Kgs, 22 #
Life :LIfe is dependent on cost.
Goal under $US0.10 /kwHR/cycle.
Examples: lead-acid battery cost $50 for 20AH 48 V pack Life 250 cycles:
Cost /kwhr/cycle= 50/250 = $0.20 ( note that this is 100% greater than goal )
Best price I can find is $600 for 50 volt 20 AH complete with charger.. can anyone find a better price?
Weight is good under 11KGs 24 # and dimensions 17 x 7.5 x 4 " or 430 x 190 x 100 mm
running my truck costs $100 per week in fuel alone, plus another $500 per month bank payment, and another $80 per month insurance.
I've spent about $1200 total on my ebike, and my batteries are warrantied to last a year.
Rather than question your 50cent/per mile figure, I'd just like to add that my options make it quite clear that running my bike as much as possible is a good idea.
Schwinn Tailwind - Toshiba Super Charge Ion Battery (SCIB)
In just a few months, the new 2009 Schwinn Tailwind should be available with Toshiba's SCIB battery which recharges in about 30 minutes. Personally, I just want the battery itself, but we likely won't find this battery available for some time yet in retail markets.
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