Westart 10ah graphene cells

999zip999

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I'm planning on dropping the hammer on 40 10ah graphene cells for $605.00usd door to door. 10c cell 20c max. For two 20s1p packs to run at 80amps. Or could be paralleled for 20ah as two 20s 10ah packs. So what you think ? Having hard time downloading pdf and link.
 
Plus in PayPal. They added a note. Need transfer from aluminum to nickel tab for ez assembly for spot welding. I don't want to spotweld just bolt together so can make as 20s2p if needed for c-rate ?
Edit
 
No link, weird disembodied messages. You drinking?

Anyway http://www.szwestart.com/ProductView.asp?ID=1083

That's the link. I would be pretty skeptical because the cycle count is a total guess and another one of their batteries was like "SAME AS TESLA" when it was a different chemistry and pouch format too.

In other words who's to say these aren't regular lipo with no graphene?
 
I was typing as I was getting new messages from them so it is an evolving conversation. Sorry flat tire. As things are changing. As a lot of talks with china. Thanks for the link. Yes some big numbers there.
Here's a link to an e.s. member build a 10ah pack. https://endless-sphere.com/forums/viewtopic.php?f=14&t=80395&p=1230344#p1245995
 
Why not just 18650's?
Why not Tesla cells?

You've been posting for a while. You're kinda all over the place... what are you looking for?
Just get some 18650's, man. Stay away from Chinese cells. Stay away from pouch cells.
 
okashira said:
Stay away from Chinese cells. Stay away from pouch cells.

Terrible advice if you want awesome performance. RC Lipo (vast majority Chinese made) is THE best battery source yet known for electric bikes. For a given discharge rate it has the highest energy capacity and they also have an awesome voltage curve other batteries can only dream about with really low internal resistance and really little voltage sag.

The only downside is you need more intelligence to safely manage them. But really not that much.

Note, these Westart cells aren't RC lipo so I have no idea whether they're good or not. Personally, I wouldn't buy at this time.
 
I'm using 10 of these in my bike: https://hobbyking.com/en_us/turnigy-graphene-10000mah-4s-15c-w-5-5mm-bullet-connector.html

They go on sale at HK for $49.99 regularly. They are already assembled and are very (very) well constructed. If you are patient for the next sale, you can save some money and make for less work on your part.

I don't have any life time info yet as I'm just finishing the bike now, but they came from HK well balanced and have stayed that way in the first few discharges on the bike.

Note that these have a little different specs in that they are only rated by HK to 15C but also are advertised at 5C charge rate.

-Jim
 
I'm having a hard time finding information about the safety of graphene cells. Ncm or lipo ? I like the claim cycle life over 18650. But the claims seem too good to be true. 18650 have so many connections and low cycle life.
 
There's loads of info on this site on all the cells stated, I have the graphene 24s 10ah worth for my new project and yes they hold the volts high and perform well but I have not had them long enough to give any long term analysis, but I've had my multistars 4s 16ah cells in a 16s 16ah configuration for 2 years now they have covered around 1000 miles or so been kept at decent voltage ranges but by no way pampered and they still show 100% capacity, The key is to build a pack with enough discharge to handle your rides max discharge easy so the battery never gets much more than ambient, never discharge them below 80% or run them flat out in the cold.

I don't use bms either I prefer to live monitor the pack voltage of individual cells and run a shunt with a watthour display then when I finish my ride the cells lift straight out and go into storage I will use a simular approach on my a2b metro but with a lockable battery's box to the rear that charges on or off the bike and can be stored away from the bike or anything else then use the old fashion method for charging of rc chargers but it's never let me down yet so I say why add complexity keep it simple silly and if it ain't broke don't fix it.
 
I don't use a bms as I have a 20ah A123 pack with four 6s pig tails for checking and balancing. I started with a 1420 then two 1220. Now just bulk charge. Just bought an anc9plus+ but only used once because there are balance after 1,004 cycles. This is because of quality and using at 90amp or below. There are just too big and heavy. Going to work may send invoice tonite for new batteries.
 
Nearly all NMC pouch cells for EVs all are using graphene and have been for many years (they use a fraction of a percent graphene in anode. )

The cell could be amazing or could be terrible, until you test, merely reading graphene in the name isn't that important.
 
And honestly, a well made pouch cell is no better or worse than a well made 18650. Both cell types have performance characteristics you need to match to your application.
 
jonescg said:
And honestly, a well made pouch cell is no better or worse than a well made 18650. Both cell types have performance characteristics you need to match to your application.

No, this is flat out wrong. 18650 has less theoretical energy per mass and volume because you've got a metal case and they have a lot of wasted space if you group them together. PLUS, to my knowledge, nobody makes 18650 format cells with RC lipo contents so you don't have really huge discharge ratings available. About 10C is a practical maximum but RC lipo goes WAY the hell up there.

Bottom line, high discharge RC lipo is the highest performance ebike battery category around and it kicks ass.
 
Nothing is safe like iron phosphate it's way way ahead of all other lithium EV chemistries in terms of safety. Of course it also has much crappier performance.
 
A123 20ah cell 20c 1,200 cycles. I think 200 amps. It's about quality. .
I think you are as you say you are flat tire or no miles. A hotdod that lost it's mustard ? Get some miles.
 
flat tire said:
RC Lipo (vast majority Chinese made) is THE best battery source yet known for electric bikes.

Reliability? Safety? Longevity? Percent of cells that are duds? I'm not sure you understand what "best" means. Because for most of us, RC lithium cobalt is far from best.
 
I'd trust buying cells from companies that have been around for decades any day over some fly by night Chinese company with an unknown quality reputation and track record. I've been selling 18650 format cells for almost 10 years, and I've tested tons of random no name Chinese companies cells. Let's just say 75% of cells from random companies are pure garbage. They might work well for a little while but later on you have problems.

Unless you're making an electric drag racing bike, I'd stick with something tried and tested.... Unless you like taking risks and doing other companies Q&A for them.
 
Chalo said:
Reliability? Safety? Longevity? Percent of cells that are duds? I'm not sure you understand what "best" means. Because for most of us, RC lithium cobalt is far from best.
The cathode material is not the important part, all the high energy lithium chemistries are dangerous iron phosphate mostly excepted.

You're right, though, I used the wrong term. RC lipo is the HIGHEST PERFORMANCE battery category available. Maybe not the best for everyone, but I think those who don't care for it are frankly a little boring considering how ridiculously vast the performance difference is between the RC lipo and even a really good 18650. Let's say you put a bunch of the 18650 in parallel so there's very little sag, well, it will still suck things compared to a RC lipo because the discharge curve goes way, way down in voltage before you've got most of the energy out. RC lipo you can finish around 3.7 and enjoy much less reduction in performance and speed at the end of your pack.
 
How do you have THAT MANY posts on the forum but you don't understand something so basic as the typical risks of this kind of battery? If you want safety, and are ok with the big performance hit, go with LiFePO4.

It's not an extremely safe battery. In the worst case, it could catch fire. You will probably be very safe with proper battery management but things like damage or manufacturing defects can lead to internal shorts that can cause fires even if you have perfect soc management.
 
I know how safe lifepo4 is and A123. Was asking the safety of graphene cells. Flat all batteries can make fires. Go play with a 9v and some steel wool. I was wondering if they are as volatile as rc lipo ect. I like a big capacity cell less connections. But also need to know about quality ? That's the question.
 
999zip999 said:
I was looking for real life safety testing of westart graphene cells. How safe are they ?

Time to get them to send you a couple samples and find out. Overcharge one, short one and crush another. Hobbyking multistars actually passed these tests in my backyard so it goes to show you never know.
 
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