Lumenier RB2205C-12 2400KV SKITZO Ceramic Bearing Motor
Thread Tools
Old Jun 30, 2006, 09:03 PM
RD Blakeslee is offline
Find More Posts by RD Blakeslee
Registered User
Data

A123 Systems Li-Ion, CBA+10X Amp. Graphs


MaxAmps donated this cell and the manufacturer's application sheet.

Because of the 10X current amplifier, all the amperage and mah figures are low by a factor of 10, so it's necessary to mentally move the decimal point one place to the right.

The voltage figures are correct as shown.

- RD
Last edited by RD Blakeslee; Oct 12, 2006 at 09:39 AM.
Sign up now
to remove ads between posts
Old Jun 30, 2006, 09:05 PM
RD Blakeslee is offline
Find More Posts by RD Blakeslee
Registered User
Charges were @ 1C.

Higher charge rates, multiple maximum rate discharges and condition checks to follow.

- RD
Old Jun 30, 2006, 09:19 PM
TMetalMan is offline
Find More Posts by TMetalMan
Registered User
Do you have any plans for pulse discharging? IMO, those continuous-current graphs aren't the best...
Old Jun 30, 2006, 09:52 PM
RD Blakeslee is offline
Find More Posts by RD Blakeslee
Registered User
The West Mountain Radio CBA system is software controlled and there is no provision for varying the amperage during a discharge.

- RD
Old Jun 30, 2006, 11:51 PM
austinelse is offline
Find More Posts by austinelse
RD,

What rate did you charge the cell at? From the spec sheet it states you can charge at up to 10 amps. That is pretty impressive quick charging.

As far as weight/capacity, its not great but I think that it has some upsides to NIMH also like the fact that it has a hard case instead of soft. They are kinda big as far as the form factor goes. I would love to hear some comments on if we should bring this cell in or not...

-Austin
www.MaxAmps.com
Site Sponsor
Old Jul 01, 2006, 12:37 AM
Lomcevak is offline
Find More Posts by Lomcevak
It flies? I like it!
Mr. Blakesly, am I reading that graph correctly and the beige line is discharge at 3C or is the decimal on the Amps misplaced?
Old Jul 01, 2006, 05:59 AM
arx_n_sparx is offline
Find More Posts by arx_n_sparx
Dismembered Member...
arx_n_sparx's Avatar
RD - Lomcevak has a point; there is a goofed up decimal place in all of those discharges, no?

Brad
Old Jul 01, 2006, 06:13 AM
RD Blakeslee is offline
Find More Posts by RD Blakeslee
Registered User
Austin, See post #2 - I'll be doing higher charge rate tests shortly. As to commercial viability for eflight, this thread might help you decide:
https://www.rcgroups.com/forums/showthread.php?t=537359

The A 123s do accomodate greater power demand, in and out, than the contemporary generation of Saphions.

Speaking for myself, graphing LiPos has never been stress-free for me. They are too unforgiving of a mistake and voltage MUST be monitored, IMO. I do not agree with the staement on FMA's website with respect to their automatic LiPo charger: "Plug and Play and Walk Away".

It would be nice to rely on the digital readout of my CC/CV P.S., (I didn't do that while graphing, of course) without need of worrying about a little inaccuracy or drift, because of the non-critical nature of the A 123 and Saphion charging algorithm.

- RD
Old Jul 01, 2006, 06:23 AM
RD Blakeslee is offline
Find More Posts by RD Blakeslee
Registered User
Guys, when The West Mountain Radio 10X amplifier is used with the CBA, the decimal point must be mentally moved one place to the right on readouts of charging amperage and discharged AH, pending a software patch to be done by W.M.R. shortly (I hope). I should have mentioned that at the outset, sorry.

https://www.rcgroups.com/forums/showthread.php?t=528314

- RD
Old Jul 01, 2006, 07:31 AM
arx_n_sparx is offline
Find More Posts by arx_n_sparx
Dismembered Member...
arx_n_sparx's Avatar
Quote:
Originally Posted by RD Blakeslee
Guys, when The West Mountain Radio 10X amplifier is used with the CBA, the decimal point must be mentally moved one place to the right on readouts of charging amperage and discharged AH
'S okay - just don't do it again!

Brad
Old Jul 01, 2006, 02:55 PM
Neil Walker is offline
Find More Posts by Neil Walker
Texas Ranger
Neil Walker's Avatar
Anyone else notice the interesting thing about the higher discharges (20C & 26C)? After the initial dip, the voltage actually increases throughout the entire discharge almost right to the end. Heating effects - suggesting a high optimum operating temp?

ps - thanks for all the work, RD
Old Jul 01, 2006, 10:02 PM
RD Blakeslee is offline
Find More Posts by RD Blakeslee
Registered User
You're welcome, Neil.

Re high Temperatures: note that the manufacturer specifies a maximum operating temperature of 185F (85C) quite a lot higher than LiPos will tolerate.

- RD
Old Jul 01, 2006, 11:36 PM
Eagleburger is offline
Find More Posts by Eagleburger
Electric Hippy
How much are these cells? If they are cheap enough I will try some in my ducted fans.
Old Jul 02, 2006, 02:26 AM
austinelse is offline
Find More Posts by austinelse
We dont have the pricing from the supplier nailed down yet. I will let you know what it will be if we decide to bring them in.

-Austin
www.MaxAmps.com
Site Sponsor
Old Jul 02, 2006, 09:50 AM
bradpaul is offline
Find More Posts by bradpaul
Suspended Account
Thank you RD for the testing. While we sometimes disagree in threads, your time and effort spent doing cell testing, considering the risk you take is appreciated.

Some observation from being around at this stage in the introduction of Lipo for RC:

- Gen 1 Lipo's were good for about 5C, now we have 15C and claimed 20C Lipos.... if A123 improves simiarilly over time the energy density delta to Lipos may disappear.

- Saftey...... I sure hope it's true...... but in the early days of Lipo's we were told they were the safest cell type yet.... worst case they would just swell up and you could throw them away.... yeah we sure know better now.

- Cycle life.... remaims to be seen at +20C but local RC boat racers here in Florida love the A123's. They usually have to throw away a Nimh pack (GP or IB cells) after around 10 cycles to remain competative. They have yet to see the need to toss a A123 pack.

Now if only A123 would put out a +3500mah cell at around 100g I would be a very happy heli flyer.

Brad


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion A123 is introducing li-ion battery packs for R/C cart213 Batteries and Chargers 82 Aug 02, 2006 11:17 PM
Discussion Apex 2100 15C, CBA/10X Amp. Graph RD Blakeslee Batteries and Chargers 12 Jul 27, 2006 12:01 AM
Discussion Enerland 2100 20C CBA/10X Amp Graph RD Blakeslee Batteries and Chargers 0 Jun 19, 2006 11:29 PM
Discussion DN Power 2100 20C, CBA/10X Amp Graph RD Blakeslee Batteries and Chargers 0 Jun 18, 2006 09:35 PM
FS: Li-ion 1350mah pack & Batt. Amer. QN-012DC Charger sgil2001 Aircraft - Electric - Airplanes (FS/W) 0 Dec 27, 2003 08:41 PM