The REAL A123 1100mAh Battery Thread - Get Them NOW!!!

Mr.Pibb · Nov 06, 2007, 08:37 PM

OK, I think I'll call this official and say that we all have a source for the new A123 1100mAh batteries, and it isn't in a DeWalt battery pack (not really anyway!

)

It turns out they are in the new Black&Decker VPX packs.
See here for the original thread. Black&Decker owns DeWalt, and it turns out that Black&Decker is who has an arrangement with A123Systems for the batteries.

I'm proud to be the first (I think) person here on RCGroups to open up a pack and verify that they really are A123 batteries.

(Edit: OK, I may not have been the first one to open them up but I was the first one to post the pictures!

)

I've attached pictures of the disassembly and the connection layout. They were real easy to take apart, but I actualy found that the spot welds on one of the cells had broken on my pack, and I don't really think I broke it when I took it apart.

Cell Size 19mm x 65mm (3/4"x 2 5/8") (approx)
Cell weight (based on weighing the pair) 42g (1.5oz)

I measured them (roughly) with a multimeter initially and both cells were 3.3v. I discharged them with a 12v light bulb until my amp meter started to fade out (at about 4.4v). I recharged them with my cellpro.
I don't think their charging algorithm for A123's knew exactly how to handle the lower capacity cells. It thought they were 90% charged when it had put in about 550 mAh, but then settled in at the very end at a very low charge rate. Part of the problem might have been that the cells were slightly out of balance. It's still charging right now, and it has put in 1030mAh and the cells are showing 3.53 and 3.59V. The one cell hit 3.59V a while ago and it has been charging at a .03A rate for quite a while.

The price at Home Depot is $20 BUT....
You can get them right now at Amazon for $19.50 each, BUY 3 GET THE 4TH ONE FREE, FREE SHIPPING. $58.50 shipped for 4 packs = $7.31/cell.

http://www.amazon.com/Black-Decker-V...4398114&sr=8-2

Looks like we can get A123's in some smaller planes now!!!

I don't have any setups to test higher current draws. I need to purchase more cells from Amazon now that I've verified that they really are A123's!

Edit:
everydayflyer (Charles) has been analyzing these cells here:
http://www.rcgroups.com/forums/showthread.php?t=768729

PeteB · Nov 06, 2007, 08:43 PM

Great job! Thank you for your effort to confirm that these are in fact A123 cells.

Carlyle Harper · Nov 06, 2007, 09:36 PM

At $7.31/cell that's still cheaper than a comparable lipo. Power to weight ratio appears to have decreased slightly compared with the original cell. I have a pico tiger moth on the work table being put together. If I used two of these cells instead of the 800mah 2s lipo I just bought there would be a 1.5 oz weight gain, basically twice the weight of the 800mah lipo. Next up to compare it against a lipo of its own size and capability. Take the flightpower evo 7.4 1345mah which weighs 2.5 oz. Since you can only use 80% of a lipo's capacity for longetivity at best that leaves 1076 mah. So then two small A123 would be 0.5 oz heavier. Not too bad at all given that ALL the mah in an A123 can be used.

Smyk · Nov 06, 2007, 09:37 PM

"You can get them right now at Amazon for $19.50 each, BUY 3 GET THE 4TH ONE FREE, FREE SHIPPING. $58.50 shipped for 4 packs = $7.31/cell."

I have been trying to get this deal, but does not go with 4 pieces of the same item. Am I doing something wrong?

Sure at $7.31 would be a great deal
I love these cell.

ZM

Mr.Pibb · Nov 06, 2007, 09:41 PM

Quote:

Originally Posted by Smyk

"You can get them right now at Amazon for $19.50 each, BUY 3 GET THE 4TH ONE FREE, FREE SHIPPING. $58.50 shipped for 4 packs = $7.31/cell."

I have been trying to get this deal, but does not go with 4 pieces of the same item. Am I doing something wrong?

Sure at $7.31 would be a great deal
I love these cell.

ZM

It shows up at the end right before you submit the order.

jbierling · Nov 06, 2007, 09:47 PM

What would be the advantage of these cells over these at less than 1/2 the price?

http://www.dealextreme.com/details.dx/sku.1879

Just (dis)charge rates?

-Joel

ozace · Nov 06, 2007, 09:49 PM

I hope these work out, amazon wont ship international with these so i will have to wait for them to show up else where.

Nice find btw

everydayflyer · Nov 06, 2007, 09:56 PM

Quote:

Originally Posted by jbierling

What would be the advantage of these cells over these at less than 1/2 the price?

http://www.dealextreme.com/details.dx/sku.1879

Just (dis)charge rates?

-Joel

Well the true A123 2300 mAh cells have proven they can be charged at 8C and last for hundreds of cycles. they can deliver 30C cont, and 50C burst be discharged to 2 volts per cell ,etc. and keep coming back for more.

It is asumed at least by me that their 1100 mSh cells are as good / rugged.

Charles

Mr.Pibb · Nov 06, 2007, 09:58 PM

Quote:

Originally Posted by jbierling

What would be the advantage of these cells over these at less than 1/2 the price?

http://www.dealextreme.com/details.dx/sku.1879

Just (dis)charge rates?

-Joel

So far I've never seen anyone get good results with the Chinese A123 copies. They typically don't measure up when it comes to discharge rates and they typically don't really have the listed capacity.

I'd like to be proven wrong, though!

They aren't 1/2 the price, they are $6.90 a cell vs $7.31 a cell for the 1100mAh real A123's (when you buy them from Amazon).

Mr.Pibb · Nov 06, 2007, 10:00 PM

Quote:

Originally Posted by everydayflyer

Well the true A123 2300 mAh cells have proven they can be charged at 8C and last for hundreds of cycles. they can deliver 30C cont, and 50C burst be discharged to 2 volts per cell ,etc. and keep coming back for more.

It is asumed at least by me that their 1100 mSh cells are as good / rugged.

Charles

I wondered when you'd jump in here

Are you going to beat the snot out of some of these cells too and give us all the results?

I just ordered 4 packs from Amazon. Once I get them I'll be able to give some better high output data.

jbierling · Nov 06, 2007, 10:00 PM

Quote:

Originally Posted by Mr.Pibb

They aren't 1/2 the price, they are $6.90 a cell vs $7.31 a cell for the 1100mAh real A123's (when you buy them from Amazon).

That link is a 2 pack -- $3.45 per cell.

-Joel

Mr.Pibb · Nov 06, 2007, 10:01 PM

Quote:

Originally Posted by jbierling

That link is a 2 pack -- $3.45 per cell.

-Joel

oops! missed that.

I'd be glad to be proven wrong, but I've yet to see good numbers on the cheap copies.

jbierling · Nov 06, 2007, 10:17 PM

Quote:

Originally Posted by Mr.Pibb

I'd be glad to be proven wrong, but I've yet to see good numbers on the cheap copies.

I have 4 headed my way, but I don't have the expertise/hardware to do a proper comparison with any other cells. My main application is bike lights which is a bit different than the usual requirements here.

-Joel

mark963 · Nov 07, 2007, 01:06 AM

OK, quick test.

Fully charged about 2-3 weeks ago. Two cells from the opened VPX pack. Roughly 13A load for about 30 seconds. Voltage as measured on the cell terminals was 5.5V or 2.75V/cell with the load applied.

Reviewing the A123 spec on the ANR26650 (M1) cell, 2.75V is like a 30A load which is supposed to be in their comfortable range. Assuming that voltage under load is an indicator of internal impedance and assuming that defines the limits of what is acceptable to a cell... That 13A load may have been OK. Since these are generally "safe" I'm more willing to abuse them to see what they do.

The 18650 size, 45g, LiFePO4 1200mA cells from Spendid's spec is supposed to handle 20A max continuous. It's possible these VPX cells are in the same neighborhood.

These results looked a lot better than I was thinking when I shelved these and cussed myself out for an impulse buy.

Mr.Pibb · Nov 07, 2007, 07:06 AM

Mark,

Looks like you beat me to the purchase and breaking the pack open, but I just beat you to posting the pictures

.

A123's are known to sag voltage under load so I guess I'm not that worried about your numbers. I'd like to see what they do under a 20C or 30C load.

I'd like to drain and recharge the batteries I have again to look more closely at how the Cellpro is handling them. I eventually took them off of the charge, but it seemed to be having a problem balancing the two cells. Also, it pushed right up to a 4A charge when it was charging, that's 3.6C which should be fine based on other A123 tests. The cells had warmed ever so slightly during the charge, but you could barely tell.

Nov 06, 2007, 08:37 PM	#1
Mr.Pibb Cleanroom Ninja Join Date: Jun 2006 Location: Lewis Center, OH Posts: 1,817	The REAL A123 1100mAh Battery Thread - Get Them NOW!!! OK, I think I'll call this official and say that we all have a source for the new A123 1100mAh batteries, and it isn't in a DeWalt battery pack (not really anyway! ) It turns out they are in the new Black&Decker VPX packs. See here for the original thread. Black&Decker owns DeWalt, and it turns out that Black&Decker is who has an arrangement with A123Systems for the batteries. I'm proud to be the first (I think) person here on RCGroups to open up a pack and verify that they really are A123 batteries. (Edit: OK, I may not have been the first one to open them up but I was the first one to post the pictures! ) I've attached pictures of the disassembly and the connection layout. They were real easy to take apart, but I actualy found that the spot welds on one of the cells had broken on my pack, and I don't really think I broke it when I took it apart. Cell Size 19mm x 65mm (3/4"x 2 5/8") (approx) Cell weight (based on weighing the pair) 42g (1.5oz) I measured them (roughly) with a multimeter initially and both cells were 3.3v. I discharged them with a 12v light bulb until my amp meter started to fade out (at about 4.4v). I recharged them with my cellpro. I don't think their charging algorithm for A123's knew exactly how to handle the lower capacity cells. It thought they were 90% charged when it had put in about 550 mAh, but then settled in at the very end at a very low charge rate. Part of the problem might have been that the cells were slightly out of balance. It's still charging right now, and it has put in 1030mAh and the cells are showing 3.53 and 3.59V. The one cell hit 3.59V a while ago and it has been charging at a .03A rate for quite a while. The price at Home Depot is $20 BUT.... You can get them right now at Amazon for $19.50 each, BUY 3 GET THE 4TH ONE FREE, FREE SHIPPING. $58.50 shipped for 4 packs = $7.31/cell. http://www.amazon.com/Black-Decker-V...4398114&sr=8-2 Looks like we can get A123's in some smaller planes now!!! I don't have any setups to test higher current draws. I need to purchase more cells from Amazon now that I've verified that they really are A123's! Edit: everydayflyer (Charles) has been analyzing these cells here: http://www.rcgroups.com/forums/showthread.php?t=768729 Attached Thumbnails 142.2 KB · Views: 1041 97.8 KB · Views: 723 164.5 KB · Views: 758 124.3 KB · Views: 1223 109.8 KB · Views: 1355 111.7 KB · Views: 2233 27.5 KB · Views: 810 Last edited by Mr.Pibb; Nov 08, 2007 at 01:26 PM.

Nov 06, 2007, 09:36 PM	#3
Carlyle Harper Registered User Join Date: Feb 2007 Posts: 985	Analysis At $7.31/cell that's still cheaper than a comparable lipo. Power to weight ratio appears to have decreased slightly compared with the original cell. I have a pico tiger moth on the work table being put together. If I used two of these cells instead of the 800mah 2s lipo I just bought there would be a 1.5 oz weight gain, basically twice the weight of the 800mah lipo. Next up to compare it against a lipo of its own size and capability. Take the flightpower evo 7.4 1345mah which weighs 2.5 oz. Since you can only use 80% of a lipo's capacity for longetivity at best that leaves 1076 mah. So then two small A123 would be 0.5 oz heavier. Not too bad at all given that ALL the mah in an A123 can be used.

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Nov 06, 2007, 08:43 PM	#2
PeteB Registered User Join Date: Jan 2002 Location: USA Posts: 2,587	Great job! Thank you for your effort to confirm that these are in fact A123 cells.

Nov 06, 2007, 09:37 PM	#4
Smyk Registered User Join Date: Mar 2004 Location: Queens, NY Posts: 481	"You can get them right now at Amazon for $19.50 each, BUY 3 GET THE 4TH ONE FREE, FREE SHIPPING. $58.50 shipped for 4 packs = $7.31/cell." I have been trying to get this deal, but does not go with 4 pieces of the same item. Am I doing something wrong? Sure at $7.31 would be a great deal I love these cell. ZM

Nov 06, 2007, 09:47 PM	#6
jbierling Registered User Join Date: Oct 2007 Posts: 3	What would be the advantage of these cells over these at less than 1/2 the price? http://www.dealextreme.com/details.dx/sku.1879 Just (dis)charge rates? -Joel

Nov 06, 2007, 09:49 PM	#7
ozace Renewed interest Join Date: Jun 2002 Location: Melbourne , Australia Posts: 8,916	I hope these work out, amazon wont ship international with these so i will have to wait for them to show up else where. Nice find btw

Nov 07, 2007, 01:06 AM	#14
mark963 Registered User Join Date: Apr 2006 Posts: 344	OK, quick test. Fully charged about 2-3 weeks ago. Two cells from the opened VPX pack. Roughly 13A load for about 30 seconds. Voltage as measured on the cell terminals was 5.5V or 2.75V/cell with the load applied. Reviewing the A123 spec on the ANR26650 (M1) cell, 2.75V is like a 30A load which is supposed to be in their comfortable range. Assuming that voltage under load is an indicator of internal impedance and assuming that defines the limits of what is acceptable to a cell... That 13A load may have been OK. Since these are generally "safe" I'm more willing to abuse them to see what they do. The 18650 size, 45g, LiFePO4 1200mA cells from Spendid's spec is supposed to handle 20A max continuous. It's possible these VPX cells are in the same neighborhood. These results looked a lot better than I was thinking when I shelved these and cussed myself out for an impulse buy.

Nov 07, 2007, 07:06 AM	#15
Mr.Pibb Cleanroom Ninja Join Date: Jun 2006 Location: Lewis Center, OH Posts: 1,817	Mark, Looks like you beat me to the purchase and breaking the pack open, but I just beat you to posting the pictures . A123's are known to sag voltage under load so I guess I'm not that worried about your numbers. I'd like to see what they do under a 20C or 30C load. I'd like to drain and recharge the batteries I have again to look more closely at how the Cellpro is handling them. I eventually took them off of the charge, but it seemed to be having a problem balancing the two cells. Also, it pushed right up to a 4A charge when it was charging, that's 3.6C which should be fine based on other A123 tests. The cells had warmed ever so slightly during the charge, but you could barely tell.