Here's an interesting question raised by an earlier post.
http://visforvoltage.org/forum/6602-lifepo4-packs-batteryspace-amp-allbattery
The duct tape packs (e.g. pingping) generally support a 1-2C discharge rate and are barely suitable for bicycle use. I have a couple bikes with pingping batteries and they work well enough but you have to take care not to floor the throttle or else the BMS cuts off the pack (to protect it from too high a discharge). That's why I say "barely suitable".
But there's a new style of LiFePO4 cell available. They are 40138(??) size cylindrical cells with 10AH size and generally have screw terminals. The screw terminals make it easier to assemble a pack. And they generally support a higher discharge rate, 10C perhaps. Also batteryspace.com carries a rectangular shaped lithium-manganese screw-top 10AH cell with similar characteristics.
The 40AH or larger cells common on the motorcycles are not suitable for a bicycle. They're too big and heavy. Plus that much power is not needed on a bicycle. Judging from my main bicycle, 10AH is sufficient for normal around-town riding.
I have a 48v20ah Headway pack and it weighs 27 lbs. pingping's 48v20ah pack weighs 21 lbs. Both those seem overly heavy for a bicycle. The tradeoff with pingping's packs is to get a higher discharge rate requires the larger pack. But these 10ah cylindrical cells already support a much higher discharge rate than pingping's.
Cutting my headway pack in half (48v10ah) would make it much smaller and weigh 14 lbs or so, that's more reasonable on a bicycle and it supports a higher discharge rate than is needed on a bicycle.
Hurm... methinks for bicycles the focus should shift away from the duct tape pack suppliers to these newer style packs.
I've been running 24 volt 10 amp hour LifeBat packs since December. I got them from Armin Pauza http://www.lithbattoz.com.au/. He was fun to deal with.
I made my own packs with thin plywood and pipe protectors using hand tools in my bedroom. What a bugger. Armin sells battery frames which made the job easier, but I would suggest buying preconfigured packs unless your a hopeless wacko like me.
These are grey BMI cells and I think they perform better than the greenish colored ones from Cyclone Taiwan. They discharge flatter [for lack of a better word] and I get maybe about 3 more Kilometers per charge per pack. They cost more too.
My packs key into the rack cutouts and into each other. I have replaced the bungy cords shown in the pictures with luggage rack straps. The batteries really take a beating on these rough roads, but I haven't had any problems.
Depends on the length of your ride. My 36v 20 ah pingbattery has been ideal, since a 10 ah of any type would leave me pedaling with several miles to go, as well as getting 100% discharged every cycle. I agree though, the 48v20ah size has proven awkward to carry on bikes, and that much weight is not so good if mounted up high on a rear rack. I think the 36-20 or 48-15 carries ok, since those sizes tend to be small enough to fit on a rear rack well, and only weigh about 16 pounds or so. 20-25 pounds does get you back to how the bike felt with 3 sla's back there. Uggh.
The 10 ah round cells are sure nice though, and if 10 ah is all you need for range, they are a great way to go. They were once very expensive, but now you can get a headway pack pretty affordable. They have had some issues finding a good bms, but they (headway) are working hard on making thier own bms now. The 48v 20 ah headway pack at affordable prices has to be REAL interesting to folks that have a motorcycle conversion. 96v 40 ah lithium would be real nice in a bigger bike.
Be the pack leader.
36 volt sla schwinn beach cruiser
36 volt lifepo4 mongoose mtb
24 volt sla + nicad EV Global
What about Headway 38120s cells? These have a high discharge rate of 5 to 10C (not quite as high as lifebatt, or BMI but more than enough for an e-bike) and they are almost half the price of lifebatt's. They are the best value/performace/per dollar in my opinion, but then again I sell them at my store. Check it out! LiFePO4 Products
-Joseph Kennedy
Kennedy Alternative Energy
http://www.kennedyalternativeenergy.com
Yes, I've concluded that the headway cells look pretty good for bikes and scooters in the 500-1500W range. has anyone used these and has comments on them? I don't mind paying twice as much for the BMI cells if it's necessary, but if not...
Wookey
Sakura s50 (Efun A)
I'm not convinced they're good for bicycles. The power range you talk about is likely above what the duct tape packs can handle (less power density) and the headway cells can handle far more than this level of power (according to the specs).
My reasoning is that they come in 10AH chunks. This means you can have a 10AH or 20AH or 30AH pack (etc).
A 36v10ah pack may be too small (not enough power on-board) while a 36v20ah pack may be too big (enough power but too heavy).
I have a 48v20ah headway pack and it weighs 27 lbs. Hm the 36v20ah pack would be about 20 lbs, which might be more acceptible for a bicycle.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
BTW I did my first initial test of the headway pack I have (there's a long story behind why I've had it for so long w/o testing it). For this test it wasn't installed in a vehicle, but with a Watt'sUp meter connected to a big resistor. The max amp draw I did was 20A or so for just a few moments (the resistor got glowing red). The voltage didn't dip. I drew 13ah out at a 4-5A rate and the voltage never got below 51v the whole time. This is a 16s2p pack, 48v nominal 20ah. Looking good so far.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
hi,
what can you recommend for brand of battery 24v 10ah lipo4.. i got 1 but it was not good.. tooks only 4miles.. im from england.. thank you
hi,
what can you recommend for brand of battery 24v 10ah lipo4.. i got 1 but it was not good.. tooks only 4miles.. im from england.. thank you
BMC 1000W motor owners;
FalconEV has a new 45A controller that works well with this motor
48V or 72V
Also, the new 10Ah A123's are here w screw in terminals
( here w me that is )
The LiFepo4 BattMan www.falconev.com
Hello all ,
Is this the correct pricing ?? from their website - $23.00 per cell .. Sooo for a 48 volt pack you'd need 15 cells as eash cell is 3.2 volts ...3.2 times 15 = 48 ... Then 15 cells times $23.00 equals $345.00... Uhhhh? that doesn't seem like too cheap to me ? Please can someone tell me if my pricing is correct ? I have no idea how much the rest of the parts would be either ????
Thank You All Very Much , Don J.
It's better to have 16 cells to make a 48v equivalent pack.
For a cells only price that's in the right ballpark - for example the price for similar cells from batteryspace.com is $35/cell and from evcomponents.com it's cheaper (but there are additional fees).
Of course the pack needs more than cells, such as a way to hold the cells in a box or other structure, and a BMS, and a charger, ..and..
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Hi!you need to lean about the battery's amphour intend to get a correct price.For example,the battery specification is 48V10ah and composed of 15unit 3.2v10ah single cells,so the correct price is 15cells times $23.00 times 10ah=$3450.00.
Hello all ,
Is this the correct pricing ?? from their website - $23.00 per cell .. Sooo for a 48 volt pack you'd need 15 cells as eash cell is 3.2 volts ...3.2 times 15 = 48 ... Then 15 cells times $23.00 equals $345.00... Uhhhh? that doesn't seem like too cheap to me ? Please can someone tell me if my pricing is correct ? I have no idea how much the rest of the parts would be either ????
Thank You All Very Much , Don J.[/quote]
Hi!
You need to lean about the battery's amphour intend to get a correct price.For example,the battery specification is 48V10ah and composed of 15unit 3.2v10ah single cells,so the correct price is 15cells times $23.00 times 10ah=$3450.00.
Hi,
Your caculate is right.I think its mean is $23.00 per 3.2V10Ah cell.For 48V10Ah,actually we always used 16 cell not 15 cell for combination.So the price is 16*23=USD$368.You can check it with that website.
We are a manufacture of LiFePO4 Battery pack,we also have 24V10Ah,36V10Ah and 48V10Ah for e-bike.Please contact me if you have interest.However,if you only want one i think it is better buy it from your country because of the shipping charge,tax and so on.If you like,we also would like to make sample for your testing first.
Krystal
Heter Battery Technology Co.,Ltd
E-mail:market04 [at] heter.biz
Tel: +86-632-5292 912
skype:krystal201048
MSN:krystal2010 [at] hotmail.com
Website: www.heter.biz