Nanophosphate batteries?

[Rolex]

I'm shopping around for a 19.8V battery for a 500 size heli.
There's the 6s LiPo 5000 going for $44 to $270.
There is also an A123 battery. Who's familiar with these? They are not dangerous like the LiPos, but I don't know what the charger should be set at...NiMh, Lipo, charge rate?

Nanophosphate is what they are, and here's a link:

http://www.hobbypartz.com/a123-systems-2300mah-19-8v-6s1p.html

 

[HPIguy]

Rolex, true A123 cells are known as LiFeP04. So you would set your charger to the LiFe mode. But there are differing LiFe technologies out there, so be sure what your packs are made of beforehand to be safe.

 

[Lessen]

My Hyperian can charge A123 & Life, but both are done on the Life setting.

 

[Rolex]

Thanks for that info.

My new charger does all the batts, including LiPo and LiFe, so I've got that covered. Any info as to memory or low voltage cut off?

 

[HPIguy]

Here's some good info on them Rolex

http://www.sincityjets.com/batteries/a123info.html

 

[K1ller Rc]

Never even herd of them? Hmmmmm??

 

[olds97_lss]

Considering all the plus's on a123 cells, surprising they aren't used more...

 

[Rolex]

HPIguy, that's some great information.
Seems like all pros and no cons. I might look into using them in all my helis since I don't have to worry about where I store them and can leave them in.

 

[hamz9561]

The nominal voltage of a LiPo cell is 3.7 V and the LiFE cells are about 3.3. A different cutoff value is needed.

 

[trax de max]

do you use cut offs when using LiFE. you do with LiPO, but i don`t think its needed for LiFE batteries

 

[Rolex]

That's what I'm wondering about. Are they similar to NiMh with no memory or low cut off to worry about?

 

[trax de max]

here is a info page.http://www.flyelectric.ukgateway.net/lithium-a123.htm
memory is confused by a lot of people.
most think its about charging, this is correct but there is also running memory, where the batteries give out a discharge of power for a few runs and that becomes memory too.
eg. if you ran Nimhs on half throttle for a few runs then decide to run it at full throttle the memory makes it give out what was that same discharge as running at half throttle.Why Nimhs decide to all of a sudden start to get hot, when the motor is pulling more amps out the battery to run full throttle.With r/c`s its not as bad as most of the time its either full throttle or none at all.people who do crawling would of experienced that, Then say there batteries are dying when really its just memory effect. They go through a lot of Nimhs not realizing that and buy better more expensive Nimhs just for it to keep happening.

 

[flm_savage]

what about weight? Aren't they around the same as nimh? That would make a big diff on a heli

 

[Rolex]

Here's the initial comparison from the trax de max link. (Thanks trax)

A123 Systems introduced a new cell in 2006. It is known mainly as 'A123' but also 'M1'. The chemistry is Lithium Iron Phosphate which is sometimes abbreviated Li-Fe or Li-FePo4. These cells have most of the good features of both Lithium Polymer and Nicads. More specifically:

* Light enough to be in same league as lipos
* High enough voltage to be almost as good as lipos
* Flat discharge curve better than nicads and lipos
* Non-critical voltage extremes so less likely to be damaged inadvertantly
* Not sensitive to heat like lipos
* Inherently much safer and don't have to be monitored like lipos
* Cab be charged quicker than nicads! (15-20 minutes)
* Cheaper than lipos (if bought as DeWalt packs)
* Physically much stronger than lipos to withstand more crashes
* Easy to make DIY charger

Disadvantages:
* Only two sizes available
* Larger/bulkier than lipos
* Likely to need new chargers and balancers
* Have to consider ESC voltage and BEC implications
* Being marketed with their charge voltage (3.6v) rather than nominal voltage; very confusing for people (eg: both Li-Ion and A123 cells are marketed as "3.6v" but they are not the same measure)

I'm about to pull the trigger on a battery, so let me know what all of you think. One of them is specifically designed with a curve for the last cell so it will fit in the nose of a 500 heli.

 

[Lessen]

I like the concept of Life cells. I think they will catch on a bit more in time, albeit NOT in the racing scene because of the voltage difference. Racers and organizations will not run at a 0.6v disadvantage and 9.9 is certainly way off the gold standard. For casual r/c use I so no reason not to go Life.

 

[Rolex]

It took me several hours to disassemble a scale fuselage to pull the heli out in order to remove the LiPo batt that was installed on the floor of the body, under the frame.
Someone here had made a post about a LiPo lighting up all on its own, and I wasn't about to take that chance with a thousand dollar heli.
No such problem with this Life batt, and the slightly lower voltage won't matter in this case.

 

[Rolex]

The battery is here, but I'm not able to get the charger to do its thing. THIS is the charger, so you can see the connections.

When I hit the start button to charge, I get the message "connection break" and it shuts off.

I'm using the balance adapter for the LiPo cells, with the batt plugged into the 6S socket.

Any advise you have to share would be very helpful.

 

[neobart]

Maybe try putting the balance tab directly in the charger, if it fits. Other then that I'm scratching my head here.

 

[Rolex]

Wow, this was an odd one.
I spent about 2 hours reading and rereading the manual and going through the settings. Some of the settings were not on my readout. Chinese instructions should be banned from this country.
It turns out that you plug the balance plug into the adapter and then into the charger, then use the banana plug outputs with the Deans connector to plug into the power cord of the battery. As soon as I had the balls to try that, I got all the readings from the battery to show up on the screen. After checking and double checking a dozen times, I finally pressed the go button.

It was a little scary since it's a 19.8 volt battery. I sat with it the whole time, keeping an eye on it and checking temps by hand.

All went well.

I also found out why they are called LiFe Po4 batteries....Lithium, Iron and Phosphate. Fortunately I excelled in Science, so I remembered that Iron was Fe for Ferrite. (Also known as a Ferrous material if it contains enough Iron.)

 

[neobart]

Ahh, they all have to have both the power leads and balance plug plugged in to charge.