BMSBattery/ECityPower Experience

kilowatt

1 mW
Joined
Sep 29, 2009
Messages
15
Location
Arlington, Virginia
I am considering buying a battery from BMS battery but am very confused over the different battery materials being used between different size packs. I am looking at the 36 volt 20 amp they came out with back in October 09 that uses 40 pieces 6665143 type cells. The pack is called a LiNiCoMn204 type; is this any good? Then I notice that the 36 volt 12 amp uses 12 pieces Lifepo4 which I assume is the pouch type batteries. I plan to watch the forums until the end of Jan and then decide; any help explaining this mix and match of cell types by amp rating and what is best would be helpful.

Thanks,

Kilowatt
:roll:
 
Li = Lithium

LiFePo4, LFP, LIthium Iron Phosphate, ( same thing, different name ) = 3.2v per cell and 12 cells per 36v pack *( heavy )

LiCo is the lightest ( cobalt ) , LiMn heavier ( manganese ) = 4.2v per cell use 10 cells in a 36v pack

8)

Most recently : http://en.wikipedia.org/wiki/Lithium-titanate_battery ( Heaviest )

All these chemical variations can be had in any format, round cell, flap foil pouch, prismatic ( metal can with threaded lugs )

Be aware of C rate.. :wink:
 
To me battery selection begins with the motor and controller selection. For example say you pick a "typical" kit.

It's a mid sized direct drive hubmotor with a 22 amp controller. So now you know you need a battery that can provide at least 22 amps in a burst, and say 15-18 amps continuously. Now you decided how far you intend to ride. Your use is likely to fall somewhere between 1 and 2 miles per amp hour. I like to use 1 amp hour per mile for full throttle riding. Usually you use less, but on windy days you might use more.

So say you need to ride 12 miles. You decide to cut it fine, and buy a 10 ah battery. So now where do you stand? you need a battery in 10 ah size that can put out 22 amps. A 10 ah battery at 1 c will provide 10 amps, so a 1 c rated battery is not good enough. A 2c rated 10 ah battery will provide 20 amps. You are getting close now, but a bit more might be better. So for a 10 ah size, you need to look for a battery type with a 3c discharge rating.

If you decide to buy a 15 ah battery, then you have 30 amps with a 2c rated cell. This is why I often recomend a 48v 15 ah battery to those that want to run a bike kit on less expensive prismatic lifepo4 that is rated 2c.


But say you only want to ride 5 miles. That's pretty short, so a higher c rate battery could be used allowing you to use a smaller pack. In that case, a 5c rated cell would give you a 5 ah pack that would put out 25 amps. This is the lure that leads some to choose high c rate lipo. They can do thier short ride with a very small and light battery.

So as you see the answer to which is best, changes depending on what your limitations are, cash, distance to ride, speed you wan to ride, etc. Personally, I just find it easier to buy a largish lifepo4 pack, and have lots of range than try to calculate my needs down to the wire. For me, this works since I have to have pretty long range anyway, living 15 miles from work. For the 400-800 watt bike kits a 36v 20 ah or 48v 15 ah lifepo4 is a pretty good choice. The battery is not too heavy or bulky( at least compared to slas) and carries ok on rear racks. But it's big enough to provide 30-40 amps for the hills, and go at least 20-25 miles. My impression is that even if you have a short ride you need to do, you will soon be enjoying longer rides if you have the capacity to do them. For me, 10 ah is just too limiting.

Another thing that affects the decision is cycle life. Lifep04 generally wins this contest, with 1000 or more cycles. Other types tend to go less cycles, but may have lighter weight, or much higher c rates, so it's a trade off what you need, lots of cycles or lots of discharge rate for a reasonable price. A123's(lifepo4) have both high c rate and high cycle life, but they cost ya.

It's very bewildering to wade though this at first, but the main thing is to let your ride tell you what you need. You may only need a couple lithium drill batteries, or a big long range pack depending on how you use the ebike.

As to the 40 cell pack you mentioned, that is not too bad for number of cells for a 20 ah pack. The known to be probematic 18650 cell lifepo4's on ebay have like 150 or so cells. That's way too many spot welds to depend on. My ping 36v 20 ah pack has 48 prismatic cells.
 
Dogman,

Thank you for the very informative reply. I have a 6 mile round trip to work but this Spring I intend to use my ebike as my primary vehicle for work, shopping and touring so I think I will go with the 36 volt 20 amp. I have a Amped 500W rear kit on a 700C hybrid and purchased a 36v 20amp Cammy_CC battery on ebay some time ago for another bike but it started to have problems with the BMS cutting out so I won't be using it on this bike. I have that battery torn apart down to 12 cell groups that made up a 2S18P pack(2ea 6S18P series connected). I'm using it as a learn about 26650 cells project and what not to buy ( I have removed 60 cells so far). Thanks again.

Kilowatt
:roll:
 
Uggg, sounds like I'm schooling the experienced then, about the round cell packs.
After that experience, I'd be likely to be looking at the headways, where a cell replacement gets easier.
 
I'm gaining experience but at a cost. I have been following the EESTOR Electronic Energy Storage Unit (EESU) development closely. It looks like a EESU will become available for E-Bike use and be 2"X2"X8" @ 400Kwh or twice the power and capacity as Lion. So, instead of spending a half grand on a new battery, I may just stick with SLA a bit longer and see how things pan out. After all, this is a US company! Go to EESTORY.com for a look.

Kilowatt
:roll:
 
there's also something called Nilar battery. It uses NIMH. Supposedly, it is good for high rate usage but I've never read about anyone using it. Electricrider.com sells them. They are about as expensive as Lifepo4.
 
Just starting a thread to detail my experience with BMS Battery/ECitypower. There's not too much info out there yet.

So far:

2/23 Ordered the following items:
1x A Pair of Bicycle Disk Brake(Front and Rear)
2x Brake Grip Throttle
1x Cute 250W Permanent Magnet Brushless Front Hub Motor
3x DJ7021-6.3-11
1x PAS--Pulse Padel Assistant Sensor
1x Twist Grip Throttle

USPS 3 day shipping to California

Total was like $170 (this is about what I expected, add 40-50% on top of the cost of goods for shipping).

2/25 Received refund saying my order had been lost

2/25 Placed another order for the following items:
1x 500Watts 36V/48V 12MOSFETs Brushless Motor Controller
1x A Pair of Bicycle Disk Brake(Front and Rear)
2x Brake Grip Throttle
1x Cute 250W Permanent Magnet Brushless Front Hub Motor
3x DJ7021-6.3-11
1x PAS--Pulse Padel Assistant Sensor
1x Twist Grip Throttle

USPS 3 day shipping to California

Total: ~$207

2/27-Present (3/9): Back and forth emails with Jack about my order... feels like they are stalling? On 3/9 I said just go ahead with my order.

Will update the thread when I receive the items & leave info on each item.
 
They just got back from the new year holiday like the 22nd or so. I bet they are having startup problems somewhere in their pipeline. Things don't work the same there as they do everywhere else.

They are a distributor of sorts and do not always stock the items they sell. If one of their suppliers is slow in starting back up you may wait a while. Might email and find out which item(s) are holding up the order and canceling those.
 
I made a similar order, and pretty much with your same timeline....ordered somewhere around 2/23, and my order has not shipped yet because Jack says they're waiting on a 100sx motor to complete the order. I received several emails from Jack asking for my requirements during the first week after I submitted my order, and then nothing since, until I emailed asking when my order would be shipped. So as of now, I am expecting my items to show up in 2-3 weeks :( I am disappointed in the lack of communication regarding the delay. I probably would of gone another direction if I had known it was going to hold up my project for over a month.

http://endless-sphere.com/forums/viewtopic.php?f=3&t=13998&start=165
 
Fitek and the rest of you ordering from BMS, all you have to do is place you order and go on vacation for a month or so and it might be there when you get back. But don't bet on it. I have place 3 orders and the more I order the longer it took. I don't think they stock anything or very little of things that need to be specific, like controllers or hub motors which you will get emails about what specs and that can be for a week or 2 before they order them. I do like the products so far but the service is by far the worst I have seen. Worse than the China duct battery boys. You will get your order but they make sure your money is good before they do anything.
Sorry I feel this way but waiting is not my best trate. I went to order a couple more 128 cute motors and some controllers when I got an email it would be 5 weeks for the motors so I just let it go.
But now since I broke my rt ankle Wednasday I might rethink it and order they cause I won't be in action for at least that.
Soryy for being bitter but as they say SHIT HAPPENS.
Dan
 
I figured I would check my order status through the website, and unfortunately it still says "processing". I ordered on 2/22 so its now been 4 weeks. I'll probably only wait another week and if they haven't shipped yet, I'm going to cancel my order and go in the direction of a RC drive.
 
Hi Keviator, 4 weeks is normal for them, as they told me controllers were in stock but the motors would take 5 weeks to produce! Send them another email about ship date and see what they say.

I do like the hubs so far, but testing is on hold as I said I broke RT Ankle the 10th of the month testing out one of my CUTE hubs for overheating. Hard running was going fine and the hubs were working great till I screwed up on a rt turn on wet road. Thanks so much that they worked well and was able to make it home about 2 miles under power not needibg to call 911.

Hope you get your hubs soon so we all can get more info on thier performance.
Dan
 
I knew going in this was going to be a very slow process. I am working on 3 e-bikes currently and I still am not really ready to use the stuff I ordered, so it's not bothering me. Now, if I don't have these items in 4 weeks, then it's going to be a problem as I need to be ready for Maker Faire in May and I figure it's gonna take me at least a month to use all these parts.

I should inquire with ecrazyman and see if he can get any similar motors, because he is relatively speedy (less than 2 weeks anyway).

I ordered some headlights and tail lights from Amazon and they came 2 days later :)
 
I oredered twice from them. The first time took a couple emails to clarify voltage of controllers. Once that was settled it took about 1 week to arrive. The second order I place I incuded controller voltage and received the order in about a week and a half.
 
Ok I don't know what is up with the world lately, but I've been having lots of delays getting either my merchandise or money from folks overseas. My ebike projects have come to a crawl from waiting on stuff.

I decided to send another email to Jack tonight asking if my order has shipped, and if it hasn't to cancel my order because I need to buy alternative motors to finish up my other bikes. Its been 5 weeks now since I placed my order. How is it that you order direct from the manfacturer/primary vendor and the wait takes this long not including the shipping?

I figured I would check their ebay listing for feedback on recent sales, and it didn't look to promising. Only 2 were listed for the past month, and both negative :( I'll keep you guys updated with what I hear back, but at this point, I would obviously not recommend bmsbattery/ecitypower until we hear more positive results from folks who have ordered recently.
 
Jonathan gave me a call the other day and pointed out that the BMSBattery website has reverted to the default Magneto (their back end software) web page. I see that today it looks like they changed visual themes or upgraded the software, but the database of products is still empty.

Something like this happened over the Chinese New Years too.

Apparently they don't know that the usual procedure for websites is to have a dev/staging system to test out upgrades on and then migrate to production overnight to prevent disruption of availability :) Or they don't have the resources for a proper setup...
 
That was a total waste of 5 weeks of waiting. It really irritates me when people hold onto my money like they've got an interest free loan, with no updates as to when I will receive my order or my money. Its poor business practice, especially when the amount is several hundred dollars. Jack promptly refunded my money with no explanations of the delay on my order. My review is a big thumbs down for BMSbattery/ecitypower.

I also noticed that their website changed again. I know 5 weeks ago when I placed my order, it used to say they shipped within 3-5 days.
 
Kevinator said:
That was a total waste of 5 weeks of waiting. It really irritates me when people hold onto my money like they've got an interest free loan, with no updates as to when I will receive my order or my money. Its poor business practice, especially when the amount is several hundred dollars. Jack promptly refunded my money with no explanations of the delay on my order. My review is a big thumbs down for BMSbattery/ecitypower.

I also noticed that their website changed again. I know 5 weeks ago when I placed my order, it used to say they shipped within 3-5 days.

For future reference, how did you request the refund?
 
I hadn't heard back from Jack in almost 2 weeks so I sent him an email and asked for the status of my order because it had been 5 weeks since placing it. I requested that if it hadn't already shipped to please cancel and refund me via paypal because I had others besides myself waiting on that stuff.
 
Ok, thanks Kevinator.

I inquired with Ecrazyman to see if he has any small hub motors like the 3.3lbs Cute motor I ordered. No response yet.
 
Ok, some movement.

4/12/2010 - Jack emailed me and said my order had been shipped and tracking information would be coming in the next day.

Never heard back from Ecrazyman about the hub motor.
 
FYI... it looks like Jack Du just quit working for eCityPower. Here's how I know and my experience.

I ordered 2 chargers from Jack 30+ days ago. The day after I made the PayPal payment Jack emailed me and said I would be getting the chargers in 3 weeks. But after 4 weeks still no chargers so I emailed and asked for a status or tracking number. To my suprise, I find out he hasn't sent them yet. Jack replied he would send out the chargers the next day and give me a tracking number at the end of the week. Well that was last week. He didn't send me a tracking number.

Another suprise... Today I just got an email from Lisa Wang at eCityPower.com and she said "sorry to inform you but Jack has quit the job", and she gave me the tracking number. That was in the morning and in the afternoon I received the 2 chargers in a DHL package. Tracking showed it only took 3 days from China to here in Los Angeles, USA. They must have paid premium shipping to get the chargers to me that fast.
 
You probably paid for the express shipping up front. My first order with them took 3 days to be delivered, my second one was 5 weeks ago and it still hasnt been shipped and the only explanation is "take it easy, it's still processing"
And I payed over $I00 in express shipping too.
I never dealt with Jack directly but hopefully the few hundred bucks of my money hasn't disappeared with him :|
 
Disappointing. The cute motors have some windings that would be useful in a 20" wheel, but everything I read about them says 'stay away unless you want a long frustrating experience.'
 
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