Thanks for the help, btw, what's a BMS board? Mine says: Smart Charger 37V Lithium Ion. Made in China
Thanks for the help, btw, what's a BMS board? Mine says: Smart Charger 37V Lithium Ion. Made in China
We should be more committed to creating tax incentives for research and development of technologies like this. Companies that develop key technologies and maintain at least 90% of their staffing here, and do their manufacturing (automated is okay) in the US should be able to operate TAX FREE.
Last edited by christ0ph; 10-22-11 at 12:37 PM.
I ride my TorceForce ebike on 36V 10Amphour LiFePo from LifeBatt.
LifeBatt are not weak China brands cells, it uses Taiwan-made cells=quality.
Battery cost $750 and it was one of the best spend $750 in my life.
I know what are you going to say - soo expensive????
But it is not your duct tape,patched up, low C rate crap with faulty electronics sold on eBay.
I bougt and installed LifeBatt in June 2008 when odometer on my TF showed 10,500 km, now I got 20,100 km /yes that's over 10,000km ,I ride year round/
Numbers speak for themselves.
I charge LifeBatt twice/day sometimes 3 times a day and ride at minimum 333 days a year - that is say 700 charges a year, means this pack will be charged 2800 times in June 2012!!!
But it is not showing any signes of aging , voltage sags is exactely as it was,
couple of week ago I discharged to 9Ah and it was strong to the end of discharge.
I buy LiFePo4 cells that screw together & BMS from (not pc capable enough to give link) bms china have accout etc they are the cheapest but one has to be very carefull to order BMS big enough for your motor. They sell a cheap pack but again shift the little thing up to get bigger BMS .
For lifepo4 battery its imperative to get the long life to have a BMS which has each cell with a signal wire I use 3.3v 12ah cell so for say 24v thats only 8 signal wires ( this called 8 S BMS ) but there again must be say for 500w -700w motor divided buy 24v = ? amps that the size BMS or they go pufffff or cut out up the hill,.
Wow you guys have saved me. All of your feedback is so great. I bought an ebike at an auction and the battery was crap and I have been planning on replacing it myself but didnt know where to start. Really glad I found you all!
I'm in new Zealand , i ve bought many batteries from a web site named BMS (don't know how to give a link) but they are by the time I get the cells & the right BMS it cost still a lot less than any other site --I am always looking for a cheaper source ,Ive learnt to make my own battery pack which is no cheaper than their cheap pack but realy good ballance for the bike ,i wish i could put picture of them. making sure the BMS is enough for bike motor is something one must be carefull of
BMS is battery management system with LIFePo4 , no cell can be discharged lower than say 2.6v & no higherthan 3.4 when charged or they stuff it . there are cheap BMS for low wattage motors which will be your first mistake like it was for me ,, get the best & they are lasting .
http://www.bmsbattery.com/ this is the the people who i've bought many batteries from 7 now buy the cells & BMS to make my own batteries. they are not generous when yuo make a mistake ordering etc but are so far the cheapest i've found -----make sure you get right Amp for BMS as they are small for low wattage & big for big wattage
Do you have any performance/charge/discharge data for your BMS battery pack? How long have you had the pack? How many charge/discharge cycles so far? What is your typical discharge "C" rate? What size charger do you use / what is your charge "C" rate?
Sorry, for all the questions. I did check out BMS web site and their prices are good, wonder if their products are too. I've have been looking into Ping Batteries who's prices are a little high but if they hold up longer and have better customer support...
I' looking into a 450 watt / 48 volt mid drive from GNG Electric. Have not decided on brushed of brushless yet.
Thanks for any information.
I have purchased several LiFePO4 battery/charger combos via a few vendors on eBay. Have also bought conversion kits with motor/wheel/battery/charger. I also worked with one mfr. to get 10 batteries custom made to fit old EVGlobal battery cases. The last time I looked, any US sellers were selling Chinese made anyhoo- can't say what situation is now. I have had no problems at all so far in 2 years' experience. But be advised, if there is a problem, shipping costs are such that some Chinese sellers are real reluctant about exchanges, and returns would cost you. No warranties, but lots of feedback to see. Yes, the duct tape looks crappy- I put 'em in nylon bags and strap to bike rack for conversions.
The specs. on these battery cells & the BMS data is all on there web site or as much as i can give anyone , The main thing is getting the big BMS , The oldest one i sold a guy has been going near every day for the last 2 months with it , the 12 ah compared to another small cell headway bat which i stuffed the bms on(was sure harder doing the BMS signal wires on it) does go further in miles distance but if any thing seems less power able to take the big hills as sometimes cutting out for a rest as they do if a good BMS.Chargers are 3A excellent all so far. I'd not touch another Brushed motor. I used before going cyclone the EZip 450w but put it on the left of bike eventualy got a throdle & controller but by that time she was near stuffed it would get so hot y]d fry an egg on it where the 500w 24v cyclone never get very hot.the 960 36v does though.
This was the LifePo4 Battery I have:
eBay - Item#230827885844
I've gone over 70 miles on it and it's been through several good charge cycles and thus far it's holding up. At this point I would be willing to recommend him if your on a tight budget. It's possible they are "duct tape" batteries" But the ones this guy had had that black textured covering over them just as they appear in the "stock" photo he provides. The charger is working as advertised and is indeed a 6 amp charger (or close to it). I get about 13 miles out of a single charge with my 350 watt 36 volt mid drive motor. It's not currently set up for the pedals to work, so that range is if you do no pedaling at all. If you have a higher power system, I would recommend getting a bigger capacity battery though. I think 12ah is the minimum that a 350watt system should run on so a 450+ would need 15ah or more.
The only thing to look out for when reading this guy's specs on the battery is that he got the "rated discharge" current wrong. Clearly it is not 12ah since if that was the case the battery would have cut out the moment I tried to use the motor. So apparently this guy gets the capacity and max discharge rate confused. He does state that the discharge rate for this battery is 2C but I have no idea that that number means in the real world.
I'd recommend asking for express shipping if you buy from him. Like most China sellers, they will ship by sea mail if you don't elect for express. Expect 8+ weeks for delivery if you don't get express shipping. With that seller, it was an extra $87 on top of the $66 shipping to get it to the US in under 6 days. Though would have been faster if there wasn't a few communication mishaps.
You can probably find one sold in the USA, but even if the seller gets them from China, they will still charge an arm and a leg for it compared to the prices you get by getting them direct from China. I'm on a shoestring budget, so I didn't have much choice.
Last edited by Apache Thunder; 07-30-12 at 11:49 AM.
Hey Powell--Can you please tell us what brand of batteries these are and a link?
PS--Why would you not state this in the post?
Is there are chart that compares 24v, 36v, 48v to the lipo batteries? Lipos have something like 10s, 12s, which is all foreign to me. I am more familiar with the voltage ones and the ah ratings. Thanks.
The typical SLA 12V battery is actually comprised of 6 - 2V cells = 6s.
1 - 12V = 12V = 6s
2 - 12V = 24V = 12s
3 - 12V = 36V = 18s
4 - 12V = 48V = 24s
The difference is that Lithiums are typically produced as singular cells, then packaged into "packs".
LiFePO4 and variations are rated at 3.2V per cell.
4s = 12.6V.
8s = 25.2V
12s = 38.4V
16s = 50.4V
Lipo - Li-ion and certain other formulations are typically 3.7V per cell.
3s = 11.1V
6s = 22.2V
7s = 25.9V I use 7s on the 24V eZips (oem 24v controller works fine with the 7s = 25.9V - 29.4V fully charged)
10s = 37V
12V = 44.4V
13s = 48.1V
Most "Lithium batteries" are labeled similar to 7s 10p
"p" standing for "parallel".
A 3.7V 2600mAh cell run 7 in series would be a 25.9V 2.6Ah battery. - 7s1p
10 of these batteries run parallel would be a 25.9V 26Ah battery. - 7s 10p
Last edited by DrkAngel; 11-05-12 at 02:18 PM.
I wouldnt buy LiFePo4 batteries from China, i wouldnt buy any Chinese brand of battery, ive had alot of experience with this, and they fail at a much greater rate, and they dont last the distance. Only buy an electric bicycle battery that uses Panasonic Battery Cells. For the extra price you will get much more distance out per charge, and will last you longer in years too.
Panasonic starts China battery line | The Japan Times Online
Panasonic Inaugurates New Lithium-ion Battery Plant in China to ...
Panasonic to Make More Batteries in China - WSJ.com
Panasonic Looks to China for Lithium-Ion Battery Manufacturing ...
Report: Panasonic to increase li-ion battery production in China
I make my own packs-- buy chinese cells (BMSbattery,or greenbatterybike ,or another) easy with big cells ,don't save much but get a better battery front mount under & ea side .The Web sites fool you into buying the low bms then have to buy another but one learns from mistakes yet agai wish i could upload a pic so you;d see the shape, made from 2 lengths 65mm pvc downpipe
I do not know about warranty but so far these people are good but u must up the Amps on the pack to be bigger to meet yr motor
Make yr own but be carefull all connections need be so as will not loosen (locktight them ,u stuff the BMS's otherwise)) get the biggest BMS . In total still cost about what a pack costs but you can get the weight down low and up front.My 500w cylone I at 70 still toss it over a fence ---23kg its weight.