found new cheap site for BMS, LiFePO4 & charger up to 18000W

[Ultraman]

I also just ordered a LiFePO4 pack from e-city. 36V/15AH with 20-30A BMS and EP-J 200w charger. $371 USD shipped to Canada. I couldn't wait for testing and reviews, I just had to go ahead and buy. But I will test it per dnmun's recommendations, and also put some endplates on it. I looked up markcycle's e-motorbike to see how he built the endplates in his build but the posts have been deleted. Any more specific advice on how to do endplates, or opinions on how necessary they are in these prismatic cells?

Jack Du was prompt and detailed in his replies, and I didn't get any pushy sales techniques.

By the way, this is my first post after having skulked around for a while.

 

[Doctorbass]

I also just ordered a LiFePO4 pack from e-city. 36V/15AH with 20-30A BMS and EP-J 200w charger. $371 USD shipped to Canada. I couldn't wait for testing and reviews, I just had to go ahead and buy. But I will test it per dnmun's recommendations, and also put some endplates on it. I looked up markcycle's e-motorbike to see how he built the endplates in his build but the posts have been deleted. Any more specific advice on how to do endplates, or opinions on how necessary they are in these prismatic cells?

Jack Du was prompt and detailed in his replies, and I didn't get any pushy sales techniques.

By the way, this is my first post after having skulked around for a while.

Welcome Ultraman !

We hope you will appreciate info availlable here!... thanks for your possible contribution about reviewing your battery pack! this is always greatly appreciated!

Doc

 

[Ultraman]

Welcome Ultraman !

We hope you will appreciate info availlable here!... thanks for your possible contribution about reviewing your battery pack! this is always greatly appreciated!

Doc

Thanks for the welcome, Doc.

I'll throw in a partial answer my own question about endplates and such. Found this thread that discusses prismatic cells and how they should be mounted "right-side-up," and also includes a link to the Thundersky user's manual showing endplate construction. http://www.aeva.asn.au/forums/forum_posts.asp?TID=867

I'll wait and see how my pack is assembled. I've been reading that such cells shouldn't swell if they're charged/discharged at a reasonable rate (2c or less perhaps), which is what I plan to do.

 

[julesa]

I'll wait and see how my pack is assembled. I've been reading that such cells shouldn't swell if they're charged/discharged at a reasonable rate (2c or less perhaps), which is what I plan to do.

Might want to limit charging to 0.25 or 0.5C at most until you're sure the cells can handle faster ... even 1C charging is really fast.

 

[dnmun]

thanks for the link uberman, joined another forum.

the big thunderskys have a large side plate too so the smaller prismatic cells may not swell so much. this is from the link he put up
(the second is dimethyl carbonate, his misspelling)


"The standard LFP cells are definitely designed for vertical mounting only.

The Liquid Electrolyte is a Solution of Lithium hexafluorophosphate in a mixture of organic solvents ...
( Ethylene Carbonate (EC) + DiEthyl Carbonate (DMC) + DiEthyl Carbonate (DEC) + Ethyl Acetate (EA) ).

The cells are constructed with a spring loaded vent valve (centre top) The valve is not intended to be fluid tight and if the cell vents while horizontal or upside down then electrolyte solution will be expelled.
(I've pulled one of mine apart to examine the valve etc !)

The other issue being that the electrolyte will not be completely covering the plate construction internally if the cell is horizontal.

The cell may appear to work (at first) but long term damage will result. Thus Thundersky have offered a 'special construction' as in Nevilleh's post.

This is all from the electrolyte point of view. There may be mechanical concerns as well. For instance, how high can you stack cells on their side ? "

 

[giveahoot]

Can't wait to see how these test and the discharge rate. Appears they have completely sold out on all LiFePO4.

 

[Ultraman]

Might want to limit charging to 0.25 or 0.5C at most until you're sure the cells can handle faster ... even 1C charging is really fast.

Thanks for the advice, slow initial charging is what I'll do. I've ordered two chargers anyway, their standard 2amp charger ($12) and the 200W EP-J 2amp charger for $32. Pretty cheap I have to say. I hope they don't break too soon. The promised shipping date is 18 days post-payment through Paypal (presumably for building and testing the battery). If anyone receives their "Jack Pack" before I do, please post some first impressions.

 

[julesa]

So I'm guessing oofnik is satisfied with his ecitypower BMS and charger?
I hope so. I bought almost the exact same ones, and expect to receive them in about a week...
Looks like they passed his testing & inspection, anyway:

http://www.endless-sphere.com/forums/viewtopic.php?f=28&t=7220&start=120

Edited to add: talked with him via PM, his BMS and charger are working great so far.

 

[Achim]

Some updates on batteries from ecitypower:

After some problems Jack sent the 48v 10ah pack with EMS. 4 days China to Switzerland! If that isn't fast!

I seem to be the first that has gotten ecity batteries so here are some pics. The BMS is integrated in the shrink tube and has the same length and width as the batts, on one hand it's good that it is integrated, less cables, less parts moving around, on the other hand it would've been nice to examine the BMS... but I'm not willing to cut the pack open. I also ordered the "EP-J 200W" charger, it's the same that pwbset got, kinda funny that the plugs between charger and battery are AC plugs.

pack voltage on arrival is 50.7v, that's ok. It weighs 4.73kg. Dimensions are 83x125x253mm, this is fine for mounting it in the bike frame.

I'll post how it performs on the bike once I get a Watt's up.

Any idea where I can get matching male plugs for the connection to my infineon controller? (don't wan't it to be shipped from China)

 

[Russell]

Achim,

Looking forward to your review since that is the same size pack I'm interested in ordering from them. Did you contact Ecitypower through email to purchase it or did you buy it from their website? Do you happen to know the "C" rating for the cells used in the pack? Did you specify the large Anderson connector for the output or is it standard?

-R

 

[caleb7777]

my 48v 15 ah should be here soon....... China to canada shipped apr 27

 

[Achim]

Russell,

I contacted ecity (Jack) directly via email. My pack was built using the battery "8081230" from here: http://www.ecitypower.com/index.php?page=75
This is 3C continuous rated. I know chinese vendors often overstate C rates, and I will find out by how much soon. But even 2C would satisfy me.
The big Anderson is standard, I didn't ask for it.

Hope you get it soon caleb, did you get a tracking number?

 

[caleb7777]

yes , hasn't hit canada yet

 

[pasteque]

hi , my name is thierry and i live in south of france , this is my first post here but i read this forum for one year quite.....

we "work" together with guillaume "gui13" who make the video with DELTA/WYE for nine continent
he deals with motors , i'm "trying my best" with battery

i think some of you may be interested by the test of ecitypower battery, i just received four 36V15Ah with 50A continous /100A peak BMS
packaging is excellent and very attentive with "kind of funny" typical metal chinese box ( ideal for your sandwich!!) to protect he battery ( seems they aimed them to be screwed on the bike , i would rather not )......
the battery where (as i asked) in very simple but really goor looking package

when battery arrived they were quite full charged

i make some decharge curve of them , will post them tomorrow , but with 45A load they all give around 15.9 ah before the BMS cuts ( around 30v) with an internal resistance that goes ( less at full charge battery and a bit higher at the end....as many liFePo battery i tested) from 110 mOhm to 130 mOhm max , really good according to my test

to have "fun" i make a 80A load to test ....no trouble all was good , except my load that burnt ......must find better fans to cool .....

so everything looks very good
last thing , i have never find so attentive and professionnal person as jack , really feel i'm their "only one" customer , and take his time all my question ......

i must thanks doctorbass to have found this site....
excuse me for my poor english , i do my best
thierry

 

[docnjoj]

Man, the quality of Lifepo4 keeps getting better! Pastique, do you mind my asking how much you paid for the battery?
otherDoc

 

[Achim]

I'm really looking forward to those discharge curves of yours thierry!

Is your also 3C continuous rated?

 

[caleb7777]

ooh my battery is in customs @ vancouver!

only a few more days I hope. Kinda slow shipping, jack says he shipped apr 29 although tracking # shows May 9 as first date, either way it is 15 days to go from china to canada, and then some more for it to get to me. :x
But it is in canada post's hands now, hurry up boys!
for 100$ shipping that seems slow.... even if it is heavy.

 

[pasteque]

take my time....in fact i'm a bit isappointed since i have troubles with the software or my power pro analyzer (since i move from XP to vista.....what a mistake!!!) and i can visualize graph but not export them as data files to this forum
i try my best......finally i take a photo of my computer's screen.......... it was the best i can do.........

this is the graph of a 14A discharge for one of the 50A continuous 36v15Ah batt

i set a 34v low voltage limit (which is fairly high but don't want to "push" new battery too much ) and when i stop the battery has given 550Wh (15.5 Ah) !

@achim : these are more than 3C rated since they are 15Ah an can provide from 50 to 100A (around 6C max)

hope i will find a solution soon and show you "real" data........

thierry

 

[EVnewbie]

Looks good Thierry,
The joys of Vista, yes... the "has to work computer" runs XP (this one) and my wife's laptop runs Vista. The results at 1C look very good and I'm curious how well it does at 2C. Take your time, don't want to fry anything.

 

[snowranger]

Wow, this is looking promising. According to that spreadsheet, a 36V 15ah runs $298 before shipping.

 

[Ultraman]

Thanks very much Thierry/pasteque for posting the info on the 36v/15ah pack. I ordered the same one a couple weeks ago from Jack at ecitypower and I'm expecting it soon. So far, so good with the two packs that have been displayed in this thread. Do we have a low-cost, reliable Chinese competitor brewing for Ping and CammyCC?

 

[pasteque]

hi,
i have tested a lot of battery since i began to have interested and to deal with them....so far i'm convinced it's the most promissing manufacturer i have tested...
they are very open to all we can suggest them to improve their products ( really different from many chinese dealers full of pretention) so don't hesitate
jack is particulary aware of the fact that offently BMS are the "bad points" in many chinese battery and are working a lot to improve their BMS (new energy transfert BMS etc.......)
in fact a french electronician well known on electric bike forum, that i contacted, has accepted to give them tips to improve their bms for example , so hope it will give good results.........

all the four bttery are the same quality , i wait until i get more of them to be sure of my opinion......also , with a new manufacturer, i always wait until i have a failure on one battery pack to see how they react according warranty for example
it's always very instructive......

i stop , you may think i'm payed to make advertissement for them

thierry

 

[dnmun]

since yo asked, someone is selling some preassembled 50A andersons, at ten times their value. i bet if someone paid shipping they could get the entire lot for $50. behind the ebay door anyway:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=260408512714

 

[snowranger]

How hard is it to change out damaged cells in these packs if needed? Similar to Ping or other.

 

[Ultraman]

How hard is it to change out damaged cells in these packs if needed? Similar to Ping or other.

I haven't seen one taken apart yet, although from the info "Allan" provided earlier in the thread they may have been in the battery business for a while, but maybe not long supplying these packs. Here's a link to what the cells look like, inside the shrinkwrap and under the BMS. And based on the way Jack seems to accomodating customers recently, I'd guess he'd sell individual replacement cells if some crapped out.

http://www.ecitypower.com/index.php?page=75