Tabless A123 AMP20M1HD-A on Ebay?

[zEEz]

ADDENDUM:

I read the taobao offer of the chinese guy selling this untabbed cells:
he is showing in photos the Internal Resistance tests that are confirming Rint
of around 2 to 9 milliohms per cell ...
Not too good, not too bad, but definitely tolerable values ... :wink:

have fun!

 

[toolman2]

ADDENDUM:

I read the taobao offer of the chinese guy selling this untabbed cells:
he is showing in photos the Internal Resistance tests that are confirming Rint
of around 2 to 9 milliohms per cell ...
Not too good, not too bad, but definitely tolerable values ... :wink:

have fun!

yep, i remember some really high quoted ir numbers from the ebay dude, but when i got them and terminated them properly, they were all the usual 2milliohms cold down closer to 1 when warm, so i think its more to do with a lame cell connection and him being strangely honest? - any of these cells with over 3 milliohms ir (and ive never seen that) are prolly not so good and it would only get worse as they age.

 

[liveforphysics]

0.8-1.1mOhm is the acceptable range for these cells.

 

[djryanrhymes]

72V x 20Ah ~ 1.5KWh.

That's a pretty small pack for those kinds of speeds (68MPH) and ranges (25 miles). I don't think it will get you anywhere near what you want.

+1 AW is right, 72v20a is not adequate for that duty cycle. My Vectrix came with a 150v30ah pack (3.7kw rated), and it MIGHT complete 20-25 miles at 70mph.

-JD

Ok, well I meant 70mph MAX. This would be a commuter motorbike so actual riding speeds would be 40 - 50mph. I have an 8 mile commute with the option to charge at the office, but I'd rather not have too. I'd prefer to have a smaller pack since the bike itself is small - 1977 CB200. I was originally planing with Headways but these A123's seem to be a better bang for the buck. Hmmm... didn't want to fork out $1500 for a 72V40ah pack but I might have too..... or maybe I'll go with the 20ah pack and try charging at work....? Suggestions?

 

[amberwolf]

Ok, well I meant 70mph MAX. This would be a commuter motorbike so actual riding speeds would be 40 - 50mph.

Ah, that makes a significant difference to the power you would be using.

If you have not already done so, you would want to use one of the various online power calculators for vehicles running at different speeds, weights, air displacements, etc. Test out teh sim with your expected commute speeds and hills and whatnot, to see how much power it will take for each part of the commute--on the flats, any hills, fast parts, slow parts, etc.

Another option is look on http://evalbum.net for a similar build to what you are going to do, and see what range@speed they get out of theirs.

The slower you go, down to about 20-25MPH, the lesser the power you will use, and it is a HUGE difference for just 10MPH more when you're above those speeds. Getting up to 70MPH and staying there requires quite a bit of power, even on the flats.

I have an 8 mile commute with the option to charge at the office, but I'd rather not have too. I'd prefer to have a smaller pack since the bike itself is small - 1977 CB200. I was originally planing with Headways but these A123's seem to be a better bang for the buck. Hmmm... didn't want to fork out $1500 for a 72V40ah pack but I might have too..... or maybe I'll go with the 20ah pack and try charging at work....? Suggestions?

I'm pretty sure you'd be a lot happier with A123 over Headway, though there are probably even better solutions depending on what you're willing to do or spend. The hardest part about dealing with *these* A123 will be mounting them up and bussing them together, compared to Headways that would just bolt rigth together with already-well-established cell holder blocks, bolts, and interconnects.

 

[zEEz]

yep, i remember some really high quoted ir numbers from the ebay dude, but when i got them and terminated them properly, they were all the usual 2milliohms cold down closer to 1 when warm, so i think its more to do with a lame cell connection and him being strangely honest? - any of these cells with over 3 milliohms ir (and ive never seen that) are prolly not so good and it would only get worse as they age.

Well, toolman2, from your experience it looks like those cells are a great bargain ...
I confess you made me to have a second though about buying them and to speed up my
125cc enduro conversion to electric project ...

Honestly I think I'll pass on that, since I want to concentrate on the smaller e-pok ... 8)

But you definitely tempted me

have fun!

 

[djryanrhymes]

Anybody has the email of this taobao guy?
I would ask him if he is willing to send me a single cell to test since I'm interested in making a big pack
in the future (60 cells) ... If he can offer me the taobao price (around 18$) + shipping with
paypal payment, I would be very keen to take 1 cell and to torture it
have fun!

Just go this email from the ebay seller:

"Hello:
My batteries are all text to be all right.You can have one or two to have a test ,you will know they are good ones.
if you want the cells ,please contect me!
best wishes
xueming208"

 

[zEEz]

Just go this email from the ebay seller:

Can you disclose his email address, so I can contact him directly? 8)

have fun!

 

[djryanrhymes]

We've been communicating through Ebay. It uses:
xuemin_jy2259ucoa@members.ebay.com.hk

 

[zEEz]

We've been communicating through Ebay. It uses:
xuemin_jy2259ucoa@members.ebay.com.hk

Thanx!
Have you decided if to buy those cells? I'm tempted, I admit!
For a motorbike with 200A max, buying 40 cells would make a comfortable 70V-40Ah pack :wink:

have fun!

 

[djryanrhymes]

Right now I'm kinda on the fence about the whole thing. Spending $3000 to convert my motorbike to electric is hard to choke when the bike is already running well and getting 77mpg. It's just slow (55mph top) and boring to ride. I'd hate to spend all that cash and it turns out to be slower and with little range.

Besides that, ya after all the research these cells seem to be the best bang for the buck. I'm still trying to figure out what the best BMS/charger would be. These cells are 3.3v and most BMS's are for 3.7v LiP04. I am unclear whether this matters. I'm assuming it's all current based so it doesn't. Correct?

 

[jimw1960]

I'm still trying to figure out what the best BMS/charger would be. These cells are 3.3v and most BMS's are for 3.7v LiP04. I am unclear whether this matters. I'm assuming it's all current based so it doesn't. Correct?

The 3.3v is a nominal voltage that they put out under 1C load. You still would balance charge them to 3.7v, so the normal lifepo4 BMS should work fine.

 

[zEEz]

Right now I'm kinda on the fence about the whole thing. Spending $3000 to convert my motorbike to electric is hard to choke when the bike is already running well and getting 77mpg. It's just slow (55mph top) and boring to ride. I'd hate to spend all that cash and it turns out to be slower and with little range.

Is your bike a cb200 and you are getting 77mpg? Going electric will mean you will be without bike for a bit of time
-now it is winter, perhaps it should be tolerable- probably you have to spend for some kind of official evaluation
of the modifications you made ... and finally you will have a bike producing just ZZZZZZZZZZZZZZZ instead of
CO, CO2, NOx, etc etc .... Investment in the battery is required, but in case you are a daily commuter
it could pay in the long run ... going 40-50mph you will get 30miles range with a 20s2p 40Ah taobao pack.
Sure, No more! So if this is tolerable for you ... it is a matter of personal taste

Besides that, ya after all the research these cells seem to be the best bang for the buck. I'm still trying to figure out what the best BMS/charger would be. These cells are 3.3v and most BMS's are for 3.7v LiP04. I am unclear whether this matters. I'm assuming it's all current based so it doesn't. Correct?

As already told, those cells are standard LiFe that are charging to 3.7v ...

have fun!

 

[djryanrhymes]

Thanks for the input. The CB200 would be coming off the road anyways during the winter since it snows here. It was the plan to do the conversion then. I am looking forward to the "ZZZZZZZZZZZ" as apposed to the "put put put cough put" it makes now. It's either I spend $500 on new exhaust and carbs or $3000 on electronic conversion. I really don't what to spend the $500 and then have the clutch go or something stupid like that. I absolutely hate working on ICE's. Hopefully the Canadian dollar will jump again. That will make the decision for me.

 

[zEEz]

I am looking forward to the "ZZZZZZZZZZZ" as apposed to the "put put put cough put" it makes now. It's either I spend $500 on new exhaust and carbs or $3000 on electronic conversion. I really don't what to spend the $500 and then have the clutch go or something stupid like that.

I think that if you talk a bit with the taobao guy, from what I understood reading around, you could
manage to acquire 40 cells with exposed contacts for around 600$ ... to make a 20s2p pack with 40Ah ...
if you have already controller and motor and you are willing to use initially the 6s RC balancers from HK
for just 15$ a pop (you need only 4 of them to balance the full pack) ... you will get the conversion
started for really an entirely acceptable amount of money ... I wish you luck ... 8)

have fun!

 

[John in CR]

Right now I'm kinda on the fence about the whole thing. Spending $3000 to convert my motorbike to electric is hard to choke when the bike is already running well and getting 77mpg. It's just slow (55mph top) and boring to ride. I'd hate to spend all that cash and it turns out to be slower and with little range.

Besides that, ya after all the research these cells seem to be the best bang for the buck. I'm still trying to figure out what the best BMS/charger would be. These cells are 3.3v and most BMS's are for 3.7v LiP04. I am unclear whether this matters. I'm assuming it's all current based so it doesn't. Correct?

Take it from someone who built an e-moto first, build an ebike instead. There's a learning curve and mistakes will be made, and with an ebike they'll be cheaper. That's not the real reason though. Other than a handful of the most advanced e-motos there are ebikes here on the forum that outperform just about any e-moto. Plus being so light and nimble ebikes are more fun, and it really must be experienced to fully understand. Maybe I'd consider building another emoto after battery energy density increases 4 to 5 fold, but due to the much better power to weight ratio of a high power ebike I will always have an ebike, even once proper emoto and ecars become available for reasonable prices.

Also, every one of my ebikes has out performed the lead pig emoto that I built first.

 

[djryanrhymes]

I think that if you talk a bit with the taobao guy, from what I understood reading around, you could
manage to acquire 40 cells with exposed contacts for around 600$ ... to make a 20s2p pack with 40Ah ...
if you have already controller and motor and you are willing to use initially the 6s RC balancers from HK
for just 15$ a pop (you need only 4 of them to balance the full pack) ... you will get the conversion
started for really an entirely acceptable amount of money ... I wish you luck ... 8)

Well, If I can get them for that price then I definitely would go ahead with the conversion project. Currently, according to his ebay pricing, 40 cells would cost me $1250.
I had a close look at the HK batteries but I had a hard time figuring out the best way to charge them. I was planning to have an onboard charger. Can you provide a link to the balancer that you are suggesting?

Take it from someone who built an e-moto first, build an ebike instead. There's a learning curve and mistakes will be made, and with an ebike they'll be cheaper. That's not the real reason though. Other than a handful of the most advanced e-motos there are ebikes here on the forum that outperform just about any e-moto. Plus being so light and nimble ebikes are more fun, and it really must be experienced to fully understand. Maybe I'd consider building another emoto after battery energy density increases 4 to 5 fold, but due to the much better power to weight ratio of a high power ebike I will always have an ebike, even once proper emoto and ecars become available for reasonable prices.
Also, every one of my ebikes has out performed the lead pig emoto that I built first.

A high performance ebike was my original plan. I opted for an emoto for legality reasons. Whizzing around doing 50mph on a uninsured bike doesn't fly with me since I'm employed by the local authorities.

Thanks to everyone for the input.

 

[zEEz]

Well, If I can get them for that price then I definitely would go ahead with the conversion project. Currently, according to his ebay pricing, 40 cells would cost me $1250.
I had a close look at the HK batteries but I had a hard time figuring out the best way to charge them. I was planning to have an onboard charger. Can you provide a link to the balancer that you are suggesting?

According to the taobao prices, one cell not exposed tab is 12$ and one exposed is 16$ ,
if you use the actual change between china currency and dollars ... :wink:
I would not settle for anything higher in case I would buy 40 cells ... 8)
so you can understand the ebay prices are -as usual- not convenient at best.

This is the balancer I use :
http://www.ebay.de/itm/320744258648?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

A high performance ebike was my original plan. I opted for an emoto for legality reasons. Whizzing around doing 50mph on a uninsured bike doesn't fly with me since I'm employed by the local authorities.

Thanks to everyone for the input.

Perfectly clear, for me too a legal e-bike with 20mph pedaling is a uninteresting piece of crap:
I prefer to pedal and build up some muscles ...
A legal e-moto would be great, if feasible within a reasonable money drain ...

have fun!