Best eBay 36V 20AH LiPo Pack?

[Jdo300]

Hello Everyone,

I'm an e-bike owner having and old 1st gen Fusin Motor's kit (Still working well so far). Last fall, the original 10AH 36V LiPo pack I had failed on my due to storing it undercharged for a long period of time (had a flat tire and left my bike sitting too long ).

So anyway, I'm looking around for a good quality replacement battery (but don't have time to build my own pack right now). I was looking around at a few eBay auctions for 36V 20AH LiPo packs and wanted to know if anyone here could give me some input on the best kit to go with.

As for my bike kit, it's a 36V 350W motor with a 14A controller. While this is the minimum specs, I want to get a battery pack with a higher discharge current rating since I plan to upgrade to a higher power kit in the future. Below are links to the three auctions that I have found so far and wanted to get your input on each. Out of these three which do you think would be test to go with? Is there anything I aught to look out for or are these all about the same quality wise?

Option 1
http://www.ebay.com/itm/Lithium-Ion-LiFePO4-36V-20AH-Electric-Bike-Battery-/110716929348?pt=US_Rechargeable_Batteries&hash=item19c73e4544

Option 2
http://www.ebay.com/itm/36v-20ah-LiFePO4-5A-Charger-Electric-Scooter-Outdoor-Bicycle-By-Sea-7-8-Weeks-/140737275908?pt=US_Rechargeable_Batteries&hash=item20c4986804

Option 3
http://www.ebay.com/itm/36V-20AH-LiFePO4-Battery-Electric-Scooter-and-E-Bike-/160796204175?pt=LH_DefaultDomain_0&hash=item2570335c8f

Option 4
http://www.ebay.com/itm/LiFePO4-Battery-36V-20AH-with-BMS-Fast-Charger-and-Bag-/330588409664?pt=LH_DefaultDomain_0&hash=item4cf89acf40

Option 5
http://www.ebay.com/itm/36V-20Ah-LiFePO4-Battery-Electronics-Bicycle-DIY-New-Energy-by-SAL-air-mail-/140761698635?pt=US_Rechargeable_Batteries&hash=item20c60d114b

If I had to guess which one I think is best, I like Option 4 since it appears to be a good price, meets my desired discharge requirements and comes with a battery bag and charger. However, if someone here has any better suggestions, I'm definitely open. What do you think?

Thanks!
Jason O

 

[cwah]

I'd vote for the A123 20AH cells for much ligther pack.

To my knowledge, Cellman is the only reliable A123 pack seller.

Check the price with him, it may worth it.

 

[motomech]

Feeling lucky are you?
I can't remember the last time a member here recommended an Ebay battery.
Ping would be the most trusted and reliable supplier.
I prefer LiCoMg over LiFePo and would probably go with a pack from BMS Battery.

 

[neptronix]

Feeling lucky are you?
I can't remember the last time a member here recommended an Ebay battery.
Ping would be the most trusted and reliable supplier.
I prefer LiCoMg over LiFePo and would probably go with a pack from BMS Battery.

+1.

Play russian roulette with 5 bullets and only 1 empty cylinder, why wontcha
There are hundreds of junk battery sellers out there and they change names pretty frequently.

Why would they want to ship you a proper working battery when they know they can ship you a total piece of junk that fails in 6 months and that it'd be too expensive to ship it back, so you just end up taking the hit?

Even better, the buyer who gets suckered gets to come here and have this forum be free tech support since they don't provide any.

We should have a sticky thread named 'i bought a crap lifepo4 battery from an unknown chinese seller on eBay'. Too bad the admins here would rather have us answer the same questions again and again.

 

[Jdo300]

Feeling lucky are you?
I can't remember the last time a member here recommended an Ebay battery.
Ping would be the most trusted and reliable supplier.
I prefer LiCoMg over LiFePo and would probably go with a pack from BMS Battery.

+1.

Play russian roulette with 5 bullets and only 1 empty cylinder, why wontcha
There are hundreds of junk battery sellers out there and they change names pretty frequently.

Why would they want to ship you a proper working battery when they know they can ship you a total piece of junk that fails in 6 months and that it'd be too expensive to ship it back, so you just end up taking the hit?

Even better, the buyer who gets suckered gets to come here and have this forum be free tech support since they don't provide any.

We should have a sticky thread named 'i bought a crap lifepo4 battery from an unknown Chinese seller on eBay. Too bad the admins here would rather have us answer the same questions again and again.

Yes you pretty much summed up the concern I have with going straight to eBay. My preference is simply to find a source for a pre-assembled battery pack. If eBay is the absolute worst choice for sources, who would you recommend? My budget for the battery is about $600 which has to include the price of the charger and a bag/case + mounting hardware to secure it to my bike.

- Jason O

 

[neptronix]

http://www.pingbattery.com/servlet/the-10/36V-20AH-LiFePO4-lithium/Detail

This is by far the best Chinese low-power lifepo4 vendor out there.
Many people here will recommend ping.

The price will be over your budget, but the battery is worth the price, as in, it will actually last

 

[Jdo300]

http://www.pingbattery.com/servlet/the-10/36V-20AH-LiFePO4-lithium/Detail

This is by far the best Chinese low-power lifepo4 vendor out there.
Many people here will recommend ping.

The price will be over your budget, but the battery is worth the price, as in, it will actually last

Thank you for the pointer. I was just looking at that very page when you posted . Yes it is true that the price will be over my budget, but since my e-bike is my primary mode of transportation, it would be well-worth the extra price to ensure that it won't burst into flames while I'm riding along.

Unless anyone has any other alternatives, I will look into getting the pack from Ping. But my next challenge is mounting the battery on my bike. What do you recommend for enclosing and mounting? The last battery I had came in an aluminum case that slid into place on my rear rack. But since this one doesn't appear to have a case, what do you all recommend?

- Jason O

 

[neptronix]

If you have good triangle space, this might work:

http://endless-sphere.com/forums/viewtopic.php?f=4&t=29211

Someone fit a 15AH 48v ping in it. If the 30A current limit of the 15AH Ping would work for you, then maybe this could do the job for you, and you could get a bit smaller battery.

 

[Jason27]

neptronix you are right about shady ebay vendors. If a battery from ping is so great why do so many people have problems with it and post on here about it?

 

[neptronix]

neptronix you are right about shady ebay vendors. If a battery from ping is so great why do so many people have problems with it and post on here about it?

I don't see a lot of complaints about the ping batteries. Nobody has decided that theirs was junk to be written off. And of all China battery sellers, you actually get service after the sale.

Usually what happens with pings is that people don't disconnect the BMS during winter, and let it sit there to overdischarge 1 cell, this killing that cell.

Every spring-winter, we hear the same complaint, yet at the same time the problem is well known.
In that case, ping can send you a replacement cell.

There are a lot of people on this forum who love their ping batteries. I am not interested in them, but if i were to recommend someone an affordable 2C capable lifepo4 pack, I wouldn't steer them any other way going off what i have read in my 2 years of daily participation here.

 

[dogman dan]

Li Ping is the guy to buy a lifepo4 battery from, if you have a 20-25 amp controller or smaller. He will actually try to help you fix the battery if you do have a problem.

But you mentioned an upgrade in the future. How many amps are you thinking of? If you want real zip, you will want a 40 amp controller, and a ping will not be happy with that. You might want to look at Emissions Free for an a123 battery, or consider the slightly riskier RC lipo from Hobby King.

In fact, the ebay batteries being sold must have improved in recent years. Much of this has to be because most of the packs offered are now using the 2c pouch cells similar to the ones in a pingbattery. You don't see near the number of complaint threads now. Ping outsells them, so he gets a few threads about problems. But you NEVER see a thread that says Ping refused to help them with a problem.

A few years back, the typical ebay lifepo4 pack was made from 150 or more 18650 round cells, and it was very very common for the tabs to pop disconnecting some of the cells. 15 ah capacity from a 20 ah pack was normal. To make things worse, at that time a few bad vendors were changing names monthly and selling factory reject packs that never worked. Shipping took 2 months by boat, and they were gone in one. We quickly became huge fans of Pingbattery because he didn't use the cheap poorly assembled tiny round cells.

Though things have improved in the last few years, I still recomend Li Ping because he was the first vendor from China that worked hard to resolve any CS issues that may occur occasionally. He's not just a vendor, he's involved in the manufacturing and knows his buisness. Other ebay vendors could be just resellers with no knowlege at all if a problem does happen. I bought my first pingbattery back in 2008, and it lasted 3.5 years. It was a dumb mistake I made that finally killed it, left it plugged into the controller with the controller on for more than a month while I was sick.

 

[dnmun]

.

 

[wesnewell]

It only takes a few minutes to build a lipo pack, and that's what I use exclusively. I've never liked the idea of lifepo4 with its many little batteries or pouches all pre-wired and a nightmare to work on if there's a problem with a cell or bms. For your setup I'd use a 15ah 12s3p lipo pack. About $200 using Turnigy 4s hard case packs.

 

[neptronix]

I wouldn't recommend RC lipo packs to someone who is new to this. You need to know what you are doing with them. If you don't, they can catch fire in a very violent way.

I don't like these lifepo4 packs either nor do i like BMSes, i love my RC Lipo.. but if i didn't understand how it worked and what it liked/disliked, i could be putting me and my lady in serious danger.

Any recommendation of RC Lipo to a newbie should come with various disclaimers.

That being said, i started out with RC Lipo, but only after reading up about how to make it not explode

 

[Jdo300]

It only takes a few minutes to build a lipo pack, and that's what I use exclusively. I've never liked the idea of lifepo4 with its many little batteries or pouches all pre-wired and a nightmare to work on if there's a problem with a cell or bms. For your setup I'd use a 15ah 12s3p lipo pack. About $200 using Turnigy 4s hard case packs.

Thank you for the input on this one. Actually, I had not considered the idea of using RC lipo's to build a pack. My initial impression of making a custom pack was buying the individual cells and making a custom box and BMS setup completely from scratch. However, I would be willing to look into the RC battery method. I have an electronics engineering background and have had some practical experience working with batteries, though not LiPOs in particular.

Could someone suggest some good threads/tutorials to look at to get up to speed on the safety precautions and handling for these batteries? I was looking on the HobbyKing website at some of the various pack sizes they carry. Ultimately, I want to build a 36V 20AH pack for my bike so would I just get three or four of the 6000 mAH pack and put in parallel? I know there has to be more details to this. Also, do most of those packs have their own built in BMS's or does one need to be added?

- Jason O

 

[neptronix]

There are some sticky threads in the battery section about this.

http://neptronix.org/posts/lipotutorial.html

Here is also a pre-production version of my series charging lipo tutorial. It is oriented towards using a hyperion 1420 or iCharger 1010b+ to charge the pack as one big unit.

 

[everest]

There are some sticky threads in the battery section about this.

http://neptronix.org/posts/lipotutorial.html

Here is also a pre-production version of my series charging lipo tutorial. It is oriented towards using a hyperion 1420 or iCharger 1010b+ to charge the pack as one big unit.

I see hobbyking now do 10s packs, how does the charging and wiring differ from 5s packs?

 

[neptronix]

There are some sticky threads in the battery section about this.

http://neptronix.org/posts/lipotutorial.html

Here is also a pre-production version of my series charging lipo tutorial. It is oriented towards using a hyperion 1420 or iCharger 1010b+ to charge the pack as one big unit.

I see hobbyking now do 10s packs, how does the charging and wiring differ from 5s packs?

Same thing, just a bit more expensive.
Another problem is that if you get a dud cell in one of those packs, you get a 10 cell pack that needs repair rather than one 5 cell pack. That sucks.

 

[wesnewell]

It takes about 10 seconds to connect 3 4s packs in series for a single 12s pack. I've used the Turingy 4s hardcase packs and they are great, and really cheap by comparison. About $22 each if/when in stock in the US warehouse. About the same from china, but shipping is a lot more. Of course you could also use 6s packs for 12s. Make it a little easier to charge at a little more cost. Here's my 10ah 18s2p pack. Could change to 15ah 12s3p in seconds. Try that with a lifepo4 battery pack.

http://endless-sphere.com/forums/viewtopic.php?f=14&t=39666&p=580314

 

[neptronix]

How do you balance 3 4S? did you have to make a special adapter for that?

 

[Jdo300]

Hi Everyone,

I have been exploring the idea of building my own RC pack for my bike but I still have a few questions.

As I am still aiming for the 36V 20AH pack, I took a look at the HobbyKing website and came across this 5000 mAh 10S1P pack here:

http://www.hobbyking.com/hobbyking/store/__20679__Turnigy_nano_tech_5000mah_10S_25_50C_Lipo_Pack_USA_Warehouse_.html

My understanding is that I could simply parallel four of these to get the 20 Ah rating I'm looking for.

@neptronix

Thank you very much for the link to your tutorial! It was very informative and really got me up to speed quickly on the subject. I am now seriously considering to go the RC battery way. All I need to do now is make up a set of parallel balancing and power cables to connect the batteries to a charger. Now, since I'm connecting this to my existing e-bile (which is a 350W 36V Fusin hub motor kit), I'm wondering if I also need to add any kind of BMS or undervoltage lockout circuit for the pack? Or are there boards built into the battery packs already? Also, for charging 4 10s packs in parallel, what charger would you all recommend?

One other thing, I noticed on the page for the 10s battery pack that it has two power leads as well as two charging leads. Does this mean that the two leads are supposed to be put in series to get the full 10s 5000 mAh rating? or is each lead a 5s 5000 mAh pack? or something I wasn't clear on this after reading the product description.

Thanks!
Jason O

 

[dogman dan]

The 10s pack is seldom recomended for the reason neptronix mentioned above. Dud cells in HK lipo runs about 10%, plus when packs age there tends to be one cell that dies first. So you are better off with 5s modules.

You get no bms with lipo, so you have to do some monitoring yourself. A cycleanalyst or other wattmeter is usefull, as well as cell level monitors such as cellog 8's.

IMO, buying lipo to run a little gearmotor is really dumb. Half the lifespan of a good lifepo4 pack. Lipo is for when the weight becomes an issue, or when you need much more amps. Niether apply for running a small gearmotor, and 15 pounds for a good 36v 20 ah ping is not so heavy.

But if you do intend to upgrade soon to a 40 amp bike, then you'd be wise to start learning about lipo now. Sounds like you have the background to jump right in easily. There is no one best way with lipo, a lot depends on if you ride and charge twice a day, or once a week. Lifepo4 is still the best choice for a regular commute for a 20 amp controller though.

Lot's of good reads on lipo basics up there in the FAQ thread you skipped.

 

[cwah]

Dogman, what's your experience with lipo lifespan? I contacted hobbyking support and they told me that nanotech has around 2-3 years of shelf life compared to standard lipo that would only have around 2 years.

But let say you get a 3 years shelf life nanotech, wouldn't we get much better battery in this time? How were the best lipo in 2009? :lol:

 

[wesnewell]

How do you balance 3 4S? did you have to make a special adapter for that?

Depends on how you want to charge them. I just parallel charge them. If you want to charge them as a single 12s pack, then you'd need to make an adapter cable or board and of course have a 12s or more charger like the Hyperion 1420i. I've got a 1420i, but it only takes seconds to reconfigure for parallel charge when all the packs are the same. When I was running 14s2p using 5s and 4s packs I made an adapter cable that turned them into 2 7s balance plugs and charged the pack as 14s.

 

[dogman dan]

I got into lipo a bit later than others. My oldest turnigy packs are not quite 2 years old now, and have lost some noticeable capacity. Never logged cycles, but it's not that many, possibly even under 100 cycles. That's moderately abused, charged to 4.2v and stored ready to use. The abused packs lasted less than 50 cycles as I learned about lipo. I used the lipo on a racing bike, and on my dirt riding bike.

Sensibly, I did my two cycles a day commuting with pingbatteries.