any reason noones tried the yuntongs/lifepo4
 

saw this and it looked pretty interesting.

https://www.unitedhobbies.com/UNITED...idProduct=5632

3.2v
2700 mah
fast charge time

seems like an a123 cell.

when i sell some stuff on in the next couple weeks i might try and pick 10 of these up for a 5s2p setup in my xt8

I'm sure people have. Does seem like an A123 cell. 5s2p would weight in at 28oz (1.75lbs), rated for 16v (3.2v/cell) and 5700mAh, for a price of $115 (plus wire, shrink, etc). Not too bad. If you do get these, make sure to post back here... :smile:

lol i sure will.

ive seen one video with these

http://youtube.com/watch?v=0c1kr7EnGV0

imagine that with a neu 1.5d:intello::intello::intello:


only reason i am slightly interested in these is because of the fast charge time.

if i can get these charged in 15-20 minutes then run for 15-20 minutes it will be a fun time for me.

I read some of the user reviews at the bottom, and people are saying it's really just like an A123 cell, and that the capacity is closer to 2300mAh.

I would say that a 10s1p configuration would be a better use of these cells. Good for a HV setup in a mt with a lower kv (1000 or so) motor. Maybe use the oem rc 100a hv esc and A KB 10XL? that united sells, and make the packs fit in and around the existing trans, etc. Would be safe to bash with! Only prob would be a charger that could charge the cells in series.

ya i read the same about it being like a a123 cell but people were also saying that there is a special way you are supposed to charge these right when you get them.

something about discharging all the way then charging them or something.

anyways we will see soon if i get them.

65mm x 25mm:oh: It's long and big:surprised: Never i'll can place it in my revo batterie tray as a 6s2p configuration, too bad...

They are an odd size, just like the A123s, but a bit narrower; you could make a hump pck of sorts I expect from 5 cells.

well ill have to see if i have room before doing anything i guess.

There not exactly like A123 cells, but there similar. Metalman has used them for quite some time...

A123 cells or the ones this thread is about? I've been using A123 cells for well over a year, and still use my first-ever homemade pack. However, I haven't heard of these 2700mah cells before, or used them for that matter. Perhaps you're confusing them with the 1300mah LiFePO4 cells I was using a couple years ago?

I'd be interested to see what the performance difference is between these and the A123's

Yea, I was refering to the LiFePO4 cells you were using. I didn't know of the mah difference, but either way, there the same type.

Yep, they are. A123s are also LiFePO4, so lots of people have been using them :angel:.

That's my video BTW :) The performance should have become even better since I switched from stock ATV to GPM Bow-Tie-Style tires and changed the connectors from MPX to Deans.
Those cells have close to 80 amps of discharge in a 2P setup.

Just a question about building a 2P A123 style pack:
i want to build a 5s2p, so can i just build 2 independant 5s pack, and after that, simply use the output power leads and connect them in parallel using a "Y" harness make with dean plug???

If YES, could i charge this 5s2p pack using this "Y" harness to charge them in same time on my Hyperion 0610i??

Thank you!

if your charger can do it im sure. you might wanna balance the packs. i do not think it is NEEDED but i would reccommend it.

and yes you can do what you are wanting to do.

it would have a little more wiring but it is ok to do.

I got 6 of the 1200mah LifePo4 cells from united hobbies. (it doesnt look like they have them in the store any more) I got them to build (3) 2 cell Rx packs for my nitros and they work fine for this application. They do charge fast like a a 123 but they hold voltage for s#!t under load. They claimed 20c on the United Hobby store, but at only a 5A constant load (thats the most I can test to with my chargers discharge mode) they hit the 2V cutoff I set at only 850mah or so. As soon as the load was removed they recovered quickly to the nominal 3.3v and were able to discharge another 100mah at a 2A load. These low loads are no where near 20c advertised capability.

I know this isnt for the 2700 cells that you linked in this thread, but I figured I would share my experience with smaller the LifePo4 cells. The 2700 might be better than the smaller ones.

I heard the United hobbies cells are not as good as the A123's and since they are even more expensive why bother.

Yes you can build 5s1p packs then use a harness to convert them to either a 10s or 5s2p pack.

I went the 6s route. The A123's are slightly lower voltage then Lipo's so the 6s pack is more like a 5s lipo pack.

I use 3s packs and then harness them to a 6s pack. Nice thing is you can then zip charge them.

Zip charge = 10-15 min charge and no need to buy a charger just a coupel of bucks of parts :)

Highflier

ya thats the only thing i was thinking about.

i know a123s are nice so why buy these other ones.

but i figured if they were what they say (2700 mah 20c 3.2v) why not give it a try.