Yesa

[Storm]

I bought two of those LifePO4 24v 10Ah batteries from Sam @ yesa through ebay and recieved them in Adelaide Australia within a week 8D, I was satisfied with communication it was personal and direct, very happy with their service... (main concern was recieving them, lol, China and all)
Cons.
I don't like the BMS exposed like that and think I will use a seperate box.
I bought the two batteries with the intention to connect in series for 48V, considering stable chemistry thought it wouldn't be a problem, when they arrived I mailed Sam whether I can series connect, he advised against and stated BMS + chargers designed for pack
Now I've two packs I don't have any use for atm and now I am waiting on the factory 48V pack from them.
I'll let you know when it arrives.

[/img]

 

[Ypedal]

Good to see you received them..

Since you can see the BMS, any chance they would " Discharge at 48v " then disconect for charging at 24v ?

 

[arohahai]

I bought two of those LifePO4 24v 10Ah batteries from Sam @ yesa through ebay and recieved them in Adelaide Australia within a week 8D, I was satisfied with communication it was personal and direct, very happy with their service... (main concern was recieving them, lol, China and all)
Cons.
I don't like the BMS exposed like that and think I will use a seperate box.
I bought the two batteries with the intention to connect in series for 48V, considering stable chemistry thought it wouldn't be a problem, when they arrived I mailed Sam whether I can series connect, he advised against and stated BMS + chargers designed for pack
Now I've two packs I don't have any use for atm and now I am waiting on the factory 48V pack from them.
I'll let you know when it arrives.

[/img]

As far as I know, Yesa is base on HONGKONG and has co-manufacturers in the mainland of China. Could you show the picture of the batteries here?

 

[Dingo]

This sounds like something got lost in translation... there should be no reason why those babies can't be discharged at 48v and charged individually, if nothing else a willingness to flip a custom-built switch or change plugs should get you there. Too bad they don't come with charge AND discharge wires, which while I haven't ever gone that route, sounds like a great way to go.

Hopefully that batt will sit centered, man! AND - if you DO figure out how to make that work, or find someone to rewire the 2x24v packs into a 48v, you will have, if you're willing to cary it all, one hell of a high-voltage ride.

 

[savuporo]

hey, my first post here.
I talked with Sam@Yesa as well sometime in spring, and he gave me lots of information, even a picture of a bike they built using their cells. However, my project was on hold for various reasons at the time so i didnt order anything.

good to hear you got functioning packs from them. let us know how it goes

 

[Dingo]

hey, my first post here.

WELCOME!

 

[Deepkimchi]

How did you pay for them? Another Chinese source is wanting a Letter of Credit, or at least a Western Union payment.

 

[Storm]

Yes discharge wires are seperate wiring to charge wires and yes probably could discharge at 48v and charge at 24 easy(only 3a tho and would therfore be 20ah).

Sam did say the cells are checked at the factory and must be equal throughout pack for series connection, I don't want to risk $$ by trying the connect of pair.

BTW: How do I load an image for you?[/img]

 

[numberonekiwi]

36V 15AH USD430 FOB CHINA

I have emailed Sam at yesa and asked about this pack and if he could make a few and put them on ebay so I can buy two

Also asked about series connection awaiting for a email back

 

[numberonekiwi]

Yes discharge wires are seperate wiring to charge wires and yes probably could discharge at 48v and charge at 24 easy(only 3a tho and would therfore be 20ah).

Sam did say the cells are checked at the factory and must be equal throughout pack for series connection, I don't want to risk $$ by trying the connect of pair.

BTW: How do I load an image for you?[/img]

I am not sure about series connecting through the BMS thats why I have asked the same questions on 36v 15AH packs but if it is not possible then I am sure that the discharge wires can be connected straight to the battery cells without connecting to the BMS

for posting images try

 

[Storm]

The thing was that he said the cells need to be close to equal to pack otherwise one may overpower others and obiously cause a short, I dunno how likely this would occur. Individual packs would be easier to fit/mount than one large block also you get two chargers with two packs (36v ~3a)

 

[Ypedal]

Ask him if the BMS ballances during charge, if it does, then the packs should be close enough to each other to discharge at 48v as long as you don't drain them 100 % DOD *( Depth Of Discharge )

If you can install a volt-meter to each pack and monitor while you ride ( The way Xyster does it ! with the analog needle meters ) stop when either pack reaches the LVC..

The circuit board on the packs ( bms ) is supposed to monitor each cell in the pack and cut the power if any one cell goes too low to prevent damamge. Depending on how the BMS is made ( and there are MANY variations out there ) some monitor total pack voltage.. some monitor each cell.. etc.. etc...etc....

DO NOT CONECT IN SERIES UNLESS GIVEN THE OK BY THE VENDOR !!!

 

[BiGH]

I bought two of those LifePO4 24v 10Ah batteries from Sam @ yesa through ebay and recieved them in Adelaide Australia within a week 8D, I was satisfied with communication it was personal and direct, very happy with their service... (main concern was recieving them, lol, China and all)
Cons.
I don't like the BMS exposed like that and think I will use a seperate box.
I bought the two batteries with the intention to connect in series for 48V, considering stable chemistry thought it wouldn't be a problem, when they arrived I mailed Sam whether I can series connect, he advised against and stated BMS + chargers designed for pack
Now I've two packs I don't have any use for atm and now I am waiting on the factory 48V pack from them.
I'll let you know when it arrives.

[/img]

sounds like a perfect battery pack for the new elation V2 motor setup (they run at 24v). - might be useful for you if you ever decide on a 2nd bike - thats driven by a chain motor.

 

[numberonekiwi]

I just got a email back from sam at yesa

We have asked our engineer.

To use two pack is OK. each pack have a BMS to control the charge and discharge .

 

[Storm]

Tha 48v 10ah LiFePO4 Battery from Yesa Arrived well packed with no damage, it took about a month to get here! quite abit longer then I expected as the 24v 10ah took only a week.

Just thought I'd let you know, incase anyone was unsure about buying from them, so far they have been reliable and honest to me. Sam has replied to all the messages I sent.

 

[Storm]

pics

 

[Storm]

pics

 

[Storm]

pics

 

[Deepkimchi]

The soldering work on the BMS looks cleaner than the Ocean*** pack someone else showed.

What type of cells are they, couldn't tell from the pictures. Polymer wafers, cylinders or?

I corresponded with Sam from Yesa also, he always responded quickly. II think Yesa is a producer, not just a broker.

Real important to me, how did you pay them ? I'm wanting to use my credit card, not get charged an arm and a leg from Western Union..

 

[Geebee]

Storm, How much do the 24v 10a packs weigh? any idea on there current limit, and do you want sell one as I might see if I can stretch to buying some lighter weight chemistry if its within my price range.

 

[Mark_A_W]

Can someone please explain to me what happens to the BMS when the packs are in series?

Why is it affected? It doesn't make sense to me.


I can understand problems with charging if the charges are earthed, but not in use when there's no common earth.

 

[Beagle123]

What are the dimensions of that pack?

 

[Storm]

Mark the cells need to be close to each other in terms of capacity and voltage, two packs may have different characteristics, it was not advised by Yesa that I connect in series.

The BMS is well two BMSs, the problem is it comes with two chargers, you could use one to charge both packs but it would be slower I guess.


Dimensions for the 24v10ah are: 230 x 85 x 65mm

Yesa advertise on Ebay and alibaba: Here's the link with some details-
http://cgi.ebay.com.au/LiFePO4-elec...ryZ75210QQrdZ1QQssPageNameZWD2VQQcmdZViewItem
Paypal is the standard and probably most secure payment method.

I will sell my pair at a lower price to cover costs on my 48v pack, they have never been charged by me and are in as new cond. I will put them on the for sale page in endless-sphere or contact me private.

The charger weighs around 500gms

 

[Mark_A_W]

I reckon your in for a penny, in for a pound now. I'd try it.

I think at worst you'd blow a BMS, which looks easily replaceable (but I'm no expert).

Realistically, what's your alternative fora 48v Lithium pack?

 

[Storm]

The pics at the top of the page are the 48v 10ah pack available from Yesa.

Will only send to Australia and can be picked up if your in Adelaide.