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Old 09-03-2016, 12:18 AM
racefreak2002 is offline
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Originally Posted by Zeeb View Post
Okay, some misconceptions here....

Remember that these cells were originally used in DeWalt cordless power tools. Those get run until they quit, then recharged and all those packs had balancing circuitry, trust me, those of us who harvested the cells from those battery packs can tell you the same.

When I cycle my A123's for cell balance issues, I take them down to 2.5 volts per cell under a 3 amp discharge load. When done, they'll usually rebound to almost 6 volts on a two cell pack. I do that three times. If there is still a problem, I run 'em down to 2.0 volts per cell and they'll usually rebound to about 5.5 volts per two cell pack when the load is removed. I've not had an issue yet with a CellPro charger not recharging them at that level.

Worst case scenario is if you run 'em dead. In most cases they can be rejuvenated by "jump starting" the charger to get some power in then go to the A123/LiFe chemistry.

Yes they will "float" about 3.45 volts per cell when taken off the charger and allowed to sit for a few minutes but when you put a load on 'em, they drop to 3.3 and pretty much stay there until they fall off the cliff. Five cell NiCD or NiMH come off the charger at about 7,2 volts and drop pretty quickly to 6.9 and then gradually decrease as they discharge to about 6.1 volts which is where you better charge 'em as there's not much left.

In short; any component rated for "6 volts" means it'll take a five cell NiCD/NiMH and with those voltages, anything rated for that will take a two cell A123/LiFe pack. While they do not like being completely drained, that is not the end of the A123 cells, I cannot speak to the LiFe as I only run the A123 brand cells for my flight packs.
Well said facts right there !!!!
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Old 09-03-2016, 01:15 AM
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Well said facts right there !!!!
I still see no reason to cycle them...
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Old 09-03-2016, 04:24 AM
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Yeah same, cycling is old school, but I also have not used A123 in years either.
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Old 09-03-2016, 05:06 AM
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Only time I cycle mine is when they are new, just to check total MAH. Otherwise, I use em as intended...
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Old 09-03-2016, 05:12 AM
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Good post Zeeb.

These cells do not benefit from cycling like the Nicad or Nimh do.

However, for peace of mind...

It may be considered that if a person is wanting to use their A123's for multi years that they may cycle them yearly to get an trend on capacities over time. I have customers still using the same packs after multiple years (Donnie is going on 7 or 8 I think with this fleet of birds)

Where to stop? I dont know. The A123 Nano Phosphates have a 10 year shelf life. This means after 10 years on the shelf you can put them into service as new.

The factory has learned a few things. For example, the 2300 cells were upgraded to 2500 cells with the same casing and 2 grams more nano-phosphate. I see 2500's cycling (new build) with more than 2600 regularly. (based at 2v per cell) The factory originally recommended 10 amp fast charge and 3 amp normal charge on the 2300's. They now recommend on the 2500 cells 10 amp fast charge and 2.5 amps normal. It may be offered they learned that a lower charge rate will contribute to longer battery life. A factory test on the 2500's showed that after 2000 full cycles of 25 amps out, 2.5 amps back in the batteries still spec'd out at 100% capacity.

As others have said, the mfg minimum voltage is 2v per cell or (4v) per 2S1P. The difference in energy between this and 2.5v (5v) is not very much at all.

Take a look at this projection from a company using the 2500 cells in a auto size battery configuration. Very interesting.
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Old 09-03-2016, 09:04 AM
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Originally Posted by WrongWayRC View Post
Where to stop? I dont know. The A123 Nano Phosphates have a 10 year shelf life. This means after 10 years on the shelf you can put them into service as new.

The factory has learned a few things. For example, the 2300 cells were upgraded to 2500 cells with the same casing and 2 grams more nano-phosphate. I see 2500's cycling (new build) with more than 2600 regularly. (based at 2v per cell) The factory originally recommended 10 amp fast charge and 3 amp normal charge on the 2300's. They now recommend on the 2500 cells 10 amp fast charge and 2.5 amps normal. It may be offered they learned that a lower charge rate will contribute to longer battery life. A factory test on the 2500's showed that after 2000 full cycles of 25 amps out, 2.5 amps back in the batteries still spec'd out at 100% capacity.

As others have said, the mfg minimum voltage is 2v per cell or (4v) per 2S1P. The difference in energy between this and 2.5v (5v) is not very much at all.

Take a look at this projection from a company using the 2500 cells in a auto size battery configuration. Very interesting.

Wow, some great information......sure takes the 'worry' factor out of having A123's in a plane for multiple years!

Thanks so much for sharing

Bill
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Old 09-03-2016, 11:54 AM
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Quote:
Originally Posted by Hinckley Bill View Post
Wow, some great information......sure takes the 'worry' factor out of having A123's in a plane for multiple years!

Thanks so much for sharing

Bill
I started with the cells harvested from the DeWalt battery packs as I mentioned. I still have some 2300mah size packs made from those cells in use as well as newer packs I've gotten from WrongWay RC. I don't know that I've ever thrown one out due to capacity loss or some other problem. I do have one cell in one of the three packs in my 2.6 Comp-Arf Extra 260 that's been getting ignorant about balancing, but that thing has got to be at least 8 years old. I guess I ought to replace it this Winter....
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Old 09-03-2016, 12:09 PM
Luchnia is offline
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Quote:
Originally Posted by WrongWayRC View Post
Good post Zeeb.

These cells do not benefit from cycling like the Nicad or Nimh do.

However, for peace of mind...

It may be considered that if a person is wanting to use their A123's for multi years that they may cycle them yearly to get an trend on capacities over time. I have customers still using the same packs after multiple years (Donnie is going on 7 or 8 I think with this fleet of birds)

Where to stop? I dont know. The A123 Nano Phosphates have a 10 year shelf life. This means after 10 years on the shelf you can put them into service as new.

The factory has learned a few things. For example, the 2300 cells were upgraded to 2500 cells with the same casing and 2 grams more nano-phosphate. I see 2500's cycling (new build) with more than 2600 regularly. (based at 2v per cell) The factory originally recommended 10 amp fast charge and 3 amp normal charge on the 2300's. They now recommend on the 2500 cells 10 amp fast charge and 2.5 amps normal. It may be offered they learned that a lower charge rate will contribute to longer battery life. A factory test on the 2500's showed that after 2000 full cycles of 25 amps out, 2.5 amps back in the batteries still spec'd out at 100% capacity.

As others have said, the mfg minimum voltage is 2v per cell or (4v) per 2S1P. The difference in energy between this and 2.5v (5v) is not very much at all.

Take a look at this projection from a company using the 2500 cells in a auto size battery configuration. Very interesting.
If I am not mistaken, this would be the five season I have been flying these batteries and they are rock solid.

I recently put 2 of your 2600 hundreds in a 35%er and I am amazed at how well they are performing. All of my planes but one 35%er have these batteries now. As close to bulletproof as one can imagine.
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Old 09-03-2016, 04:13 PM
rcflip - Ozzy is offline
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Yeah I like A123 when I did use them, did not like the weight and the low voltage made them redundant for me but I understand why people like and use them. You would be surprised how robust a SubC nimh is though, we abused them back in the 1/10th scale racing days, but i would not put them in a plane either.
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Old 09-04-2016, 05:16 AM
WrongWayRC is offline
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Quote:
Originally Posted by Hinckley Bill View Post
Wow, some great information......sure takes the 'worry' factor out of having A123's in a plane for multiple years!

Thanks so much for sharing

Bill
Great, you are welcome. I guess the only thing that I might add is to inspect your wiring on some kind of schedule for any chaffing or other issues. As any electrical component does, the batteries should be soft mounted on Velcro or foam.

Also many brands will use spot welded tabs to join the wires and if the battery is not properly installed and is exposed to high vibration there could be issues with long term tab separation.(usually low probability) At WWRC we have a technique that allows us to join the wiring directly to the cells on all of our A123' to avoid the possible long term tab issue.
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Old 09-04-2016, 07:00 AM
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Originally Posted by WrongWayRC View Post
Great, you are welcome. I guess the only thing that I might add is to inspect your wiring on some kind of schedule for any chaffing or other issues. As any electrical component does, the batteries should be soft mounted on Velcro or foam.

Also many brands will use spot welded tabs to join the wires and if the battery is not properly installed and is exposed to high vibration there could be issues with long term tab separation.(usually low probability) At WWRC we have a technique that allows us to join the wiring directly to the cells on all of our A123' to avoid the possible long term tab issue.
That's just one of the reasons I like Richards A123's, He does great work.
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Old 09-04-2016, 03:10 PM
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Originally Posted by WrongWayRC View Post
.............................. At WWRC we have a technique that allows us to join the wiring directly to the cells on all of our A123' to avoid the possible long term tab issue.
Got any details of that process WrongWay?
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Old 09-12-2016, 01:32 PM
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That is the best excuse that I have ever heard for not having a spot welder. I would buy packs from Hangtimes Hobbies that DOES have a spot welder.
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Old 09-12-2016, 01:46 PM
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Old 09-12-2016, 03:08 PM
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