Looking for the best battery for my ebike.

[mateusleo]

Changing a little bit the subject of this topic while sun-thing is away on ebay and can't asnwer me, what do you guys thinkg about my bike? I'm posting some links of the pictures, and if they don't fit in the layout, just copy its direct link and u'll be able to see them in full-size.

The frame is made to quietly fit the battery case, so it looks more "normal". I bought it this way and made some mods in somethings that are less important...So, what do you guys think about it? Is it a good bike? What about the motor(i know nothing aobut it, just what you can see in the picture)? =D

 

[torker]

I think it looks pretty good. I like how they bent the bottom tube on the triangle to make room for the battery. Also it seems to have a beefy looking steel torque arm for the motor. Good spot for the controller right between the batts and motor and out of the way. Disc brakes too. And it looks like a 1 1/8" headset so a fork upgrade might be easy to do down the road. Nice simple functional design all around.

Back on the subject I would like to hear from folks about the different batteries. I looked at the sunthing site. Looks like they are on Chinese holiday till the 18th. Great prices. I noticed they are pouch cells. The ones I linked to are cylindrical cells. Not sure which might be better. I am also close to pulling the trigger on a battery purchase.

 

[mateusleo]

I think it looks pretty good. I like how they bent the bottom tube on the triangle to make room for the battery. Also it seems to have a beefy looking steel torque arm for the motor. Good spot for the controller right between the batts and motor and out of the way. Disc brakes too. And it looks like a 1 1/8" headset so a fork upgrade might be easy to do down the road. Nice simple functional design all around.

Back on the subject I would like to hear from folks about the different batteries. I looked at the sunthing site. Looks like they are on Chinese holiday till the 18th. Great prices. I noticed they are pouch cells. The ones I linked to are cylindrical cells. Not sure which might be better. I am also close to pulling the trigger on a battery purchase.

By what i heard here, sunthing will be my choice. The only problem is that his ebay announce says he doesn't ship to Brazil, but i sent him a private message to check if we can solve this problem to me XD

 

[dogman dan]

Bear in mind, it's chinese new year. He may not check his messages for another week. Same for ping, or any others.

Re the cell count if anybody cares, ping has been using a 5 ah pouch cell for some time. So a 48v 20 ah would be 4 of those paralelled, x 16 cell groups. Likely the same deal with sunthings.

Better be damn sure that 20 ah will fit. It might in your frame, but it doesn't in most bikes. 48v 15 ah will be enough to run the motor fine, and weigh less.

 

[999zip999]

I'm glad to read that you are going to a premade lifepo4 pack with bms. This is a better plug and play idea.

 

[torker]

Anyone care to chime in on the pouch vs cyl. cell difference.? Advantage/ disadvantages. The Cohnis and batt space seem to use the 26650 but the Sunthing is pouch.

 

[mateusleo]

Anyone care to chime in on the pouch vs cyl. cell difference.? Advantage/ disadvantages. The Cohnis and batt space seem to use the 26650 but the Sunthing is pouch.

I guess the cylidrical ones are more resistent against impact due to their metal coating, but since the pouches are inside an epoxi case, they are protected. So, it seems like theres not a big difference.

 

[torker]

Yea, Not too worried about the impact resistance. I plan to fab an enclosure to protect them.

 

[mateusleo]

I received an answer to know the price of this battery http://victpower.en.alibaba.com/product/686808424-214260108/e_scooter_48V_lifepo4_20AH_Battery_Pack.html made by victpower. And here is the email he sent me:

Dear:Mateus

How are you ?

Im so happy to hear from you

About A123 48V20AH lifepo4 battery pack with BMS (20-40A)

We will use A123 20AH cell to assembly,its 16s1p

Dimension:116x160x230mm

Working currnt :20A

Peaking current :40A

Quotation:266.6USD (pack+bms)

Delivery:UPS EMS DHL etc.

Delivery Time :5-7working days

Payment :T/T or WU

I will wait for your reply

Best Regards

1)The working current is said to be 20A, but my motor is 1000watts, so it will use like 21A, can i use this battery on my motor?
2)It is so cheap that i don't know if it is trustable. Also, the email he used to answer me is quite wierd: 1721964559@qq.com
I'm confused. Could someone give me some info about victpower? I need to know about his quality and i also want to know if the battery (the link above) is trustable. Also, let's start a little essay here: victpower X sun-thing28?
Ps: I felt unsafe about victpower, alibaba isn't a known site for me and its too confute, alot of batteries that look exactly the same ....

 

[SamTexas]

Quotation:266.6USD (pack+bms): How much is shipping to the USA?

 

[999zip999]

I would run away from victpower and their are many problem threads here on E.S.Re: Are the VictPower A123 AMP20's legit?
Don't buy from victpower, they are junk. Even if these cells pass you inspection, they may die after a month. I had a pallet from them - its ridiculously bad.
That a quote from Ohzee

 

[geeeyejo1]

[/quote]
1)The working current is said to be 20A, but my motor is 1000watts, so it will use like 21A, can i use this battery on my motor?
2)It is so cheap that i don't know if it is trustable. Also, the email he used to answer me is quite wierd: 1721964559@qq.com
I'm confused. Could someone give me some info about victpower? I need to know about his quality and i also want to know if the battery (the link above) is trustable. Also, let's start a little essay here: victpower X sun-thing28?
Ps: I felt unsafe about victpower, alibaba isn't a known site for me and its too confute, alot of batteries that look exactly the same ....[/quote]
Their specs have a working (continuos) current of 20A with 40A peak - that or another battery with similar specs would be fine for your motor and controller. Don't know about this vendor but the other posters appear to have some concerns and bad experiences so I would steer clear. Usually if something is too good to be true, it often is! I have explored Alibaba but stick with Ebay due to their buyer protection and feedback system. I did a lot of battery research prior to my purchase as I had a limited budget (I had to sell three vintage bikes to finance the project!) and ended up going with Sunthing due to his price, and good Ebay feedback. After Chinese New Year, hopefully he will get back to you and let you know if he can ship to Brazil!

 

[999zip999]

Advise verus price ?

 

[geeeyejo1]

Advise verus price ?

? I paid $426 for my Sunthing pack including shipping to the US

 

[geeeyejo1]

Anyone care to chime in on the pouch vs cyl. cell difference.? Advantage/ disadvantages. The Cohnis and batt space seem to use the 26650 but the Sunthing is pouch.

I guess the cylidrical ones are more resistent against impact due to their metal coating, but since the pouches are inside an epoxi case, they are protected. So, it seems like theres not a big difference.

Actually I have heard the cylindrical cells are more subject to having the welded tabs that connect the cells break on impact and/or strong vibrations versus the cells themselves being damaged. I believe the connections for the pouch cells are more vibration/impact resistant and therefore less subject to connection issues down the road...

 

[Hillhater]

Advise verus price ?

Have you costed similar spec packs from other suppliers ?
If you did, you would realize that is a unrealistic cheap price for a quality A123 pack !

 

[mateusleo]

I would run away from victpower and their are many problem threads here on E.S.Re: Are the VictPower A123 AMP20's legit?
Don't buy from victpower, they are junk. Even if these cells pass you inspection, they may die after a month. I had a pallet from them - its ridiculously bad.
That a quote from Ohzee

Thanks, you said all that i needed to hear, it was ridiculously cheap to be true.

Their specs have a working (continuos) current of 20A with 40A peak - that or another battery with similar specs would be fine for your motor and controller. Don't know about this vendor but the other posters appear to have some concerns and bad experiences so I would steer clear. Usually if something is too good to be true, it often is! I have explored Alibaba but stick with Ebay due to their buyer protection and feedback system. I did a lot of battery research prior to my purchase as I had a limited budget (I had to sell three vintage bikes to finance the project!) and ended up going with Sunthing due to his price, and good Ebay feedback. After Chinese New Year, hopefully he will get back to you and let you know if he can ship to Brazil!

Yeah, hope he can ship to Brazil, otherwise i'll find someone to ship it to me. His batteries seems really nice and affordable.

 

[ohzee]

I would run away from victpower and their are many problem threads here on E.S.Re: Are the VictPower A123 AMP20's legit?
Don't buy from victpower, they are junk. Even if these cells pass you inspection, they may die after a month. I had a pallet from them - its ridiculously bad.
That a quote from Ohzee

Not sure how I missed this before , but I never made that quote.. heck I doubt half of what I say on here is even worth quoting.

Anyway love ya zip , but you have the wrong source there. If you can produce the post Ill eat my words.

 

[999zip999]

Do not buy the A123 20ah pack from Victpower it has solder taps of copper and alumiun. Copper and alumiun can't be solder as they try. Or go solder you some alumiun and copper and get back to us.

 

[ohzee]

http://endless-sphere.com/forums/viewtopic.php?f=14&t=47521#p696721

Found the post was circuit.. no harm no foul

 

[999zip999]

Sorry Ohzee for the miss quote but was a copy qutoe of curcit's in the victpower legit thread you added in . Yes much happy for the love. So back at you. What you doing the 14th.

disclaimer : My 24s A123 20ah pouch is balance and charging well after a 4 month storage. From in the Victpower midwest group buy 8-10mos ago. Meaning when they first came available.

So we aren't going to lunch ( I'll eat my words ) ?
To bad these jokes don't travel well.

 

[ohzee]

Sorry Ohzee for the miss quote but was a copy qutoe of curcit's in the victpower legit thread you added in . Yes much happy for the love. So back at you. What you doing the 14th.

disclaimer : My 24s A123 20ah pouch is balance and charging well after a 4 month storage. From in the Victpower midwest group buy 8-10mos ago. Meaning when try first came available.

So we aren't going to lunch ( I'll eat my words ) ?
To bad these jokes don't travel well.

haha thanks for the laugh bro.. on the 14th Ill be wishing I had a gf I wanted to buy something for or that the wife would let me :0)

 

[dnmun]

Anyone care to chime in on the pouch vs cyl. cell difference.? Advantage/ disadvantages. The Cohnis and batt space seem to use the 26650 but the Sunthing is pouch.

I guess the cylidrical ones are more resistent against impact due to their metal coating, but since the pouches are inside an epoxi case, they are protected. So, it seems like theres not a big difference.

Actually I have heard the cylindrical cells are more subject to having the welded tabs that connect the cells break on impact and/or strong vibrations versus the cells themselves being damaged. I believe the connections for the pouch cells are more vibration/impact resistant and therefore less subject to connection issues down the road...

this is wrong. the reason the the steel jacket is preferable is because it keeps the layers of electrode and separator and electrolyte under pressure so the gas formation inside doesn't cause the electrolyte gel to pull away from the electrodes and the separator. this why you have to keep the pouch cells under compression.

i have never seen a welded tab break on a cylindrical cell, but the pouch tabs will break from vibration and i have seen that a lot.

 

[mateusleo]

Actually I have heard the cylindrical cells are more subject to having the welded tabs that connect the cells break on impact and/or strong vibrations versus the cells themselves being damaged. I believe the connections for the pouch cells are more vibration/impact resistant and therefore less subject to connection issues down the road...

this is wrong. the reason the the steel jacket is preferable is because it keeps the layers of electrode and separator and electrolyte under pressure so the gas formation inside doesn't cause the electrolyte gel to pull away from the electrodes and the separator. this why you have to keep the pouch cells under compression.

i have never seen a welded tab break on a cylindrical cell, but the pouch tabs will break from vibration and i have seen that a lot.

Theres a rubberized material inside my battery case, that avoids vibration and prevent any shake that could occur to the battery =)

 

[dnmun]

it is not the shaking of the battery that casues the metal fatigue in the tab. the cases i have seen of the tabs breaking from vibration were because the tabs were all connected to a pcb above the pouches and the pcb would vibrate because there were wires connected to the pcb that added energy to the movement so that the places where the tabs were kinked then the tabs eventually just separated.

this is different from the case where the old type ping packs would expand with age and the outer pouches were pushed so far out that the tabs were torn as they were pulled up from where they get folded down between the pouches. that was a combination of the metal tab being crimped 180o on exit from the pouches, so the crease where they were folded caused the aluminum tab to be subject to the corrosion from the LiF6 in the electrolyte and removal of the aluminum metal at that crease by electromigration of the aluminum and a void formed that weakened the tab so it would pull apart easily. this is how most of the old ping packs ended up dead.

this is the major improvement that ping has made to his batteries. the new 5Ah signalab pouches have a much higher C rate, because of the wide tabs, pouches are well constructed so none of them seem to ever puff up, just a much better battery than he originally made. i think his pouches now are higher quality than the other lifepo4 pouches.

i look forward to seeing how these sun-thing pouches are made and assembled. it will be useful to analyze how the BMS works, and if it is covered with the black goop so it cannot be repaired.