CR-123 Lithium Ion - Lipo alternative?

[Alistair Taylor]

Calling all leccy fliers

Several electric flight distributors are in the process of developing, or have already marketed lithium-ion/Saphion cells for electric flight.

Is anyone out there already using the now widely available rechargeable CR123 Lithium Ion cells for electric flight?

e.g. (sorry for long link)

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250141164015&ru=http%3A%2F%2Fsearch.ebay.co.uk%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26_trksid%3Dm37%26satitle%3D250141164015%26fvi%3D1

These give out 3volts, have 1000MaH capacity, are very light, and are available for £1 each. This sounds like an absolute bargain, provided they are capable of delivering reasonable amps.

Does anyone have any experience with these cells?

AlistairT

[scott cuppello]

Just looking at it today funnily enough, looks like one or two of us is going to have to try it. I do get the impression that initial packs are going to be a bit limited in terms of choice of voltage & capacity.

[Alistair Taylor]

I'd be surprised if they're capable of delivering more than 10amps (10c approx), but on a more practical level I would like to find out how resistant they are to soldering, whether the Li-Ion setting on my Prodigy MK1 charger will cope with 3-cell packs, you know, important stuff like that ~:o)

AlistairT

[David Ashby - Moderator]

We've been promised some from BRC Hobbies to review/have a look at, will report back soon, we hope.

David.

[Ian]

A colleague uses them at my club with great results.They are 3.3 volts I believe and can be soldered together to form packs.

[Ian]

Sorry I meant A123 cells 2400mah capacity !

[Helidel]

I have used them in the past but although
stronger than Lipos (being metal cased)their extra weight eventually put me off.

These were in a 3 cell pack by Overlander

[John Ogier]

Alistair, you mention Saphion cells. They are lithium phosphate not ion. I have been using some for about a year now and find them good. They are 6S2P 2400 and can be discharged at 15C 36 amps. One advantage over lipos is they can be discharged to almost empty without any danger of fire. Being in metal cans they are slightly heavier than my 5S1P 3300 lipo equivalent but still give a good performance. Price wise a little cheaper than lipos.
John

[Alistair Taylor]

Thanks for the replies.

I might give these a try as either micro 6V RX packs, or speed 400 sized packs. I suspect that in the latter application they'll be happier in relatively low-current aplpications.


AlistairT

[Bill Ashton]

Charging requirements for Saphion Cells - can you use a Delta-peak type - when do you know cells are fully charged?

[John Ogier]

Bill,
I charge my saphions on a chameleon charger on the li-ion 3.6V program. This seems to work well. You can't balance them as there are no balance leads on the bats., but I have had no problems so far without the balancing; I still put around 2200-2300ma in each time. The charger switches off automatically at the end of charge and displays what it has put in. I have just bought a Bantam BC6 charger which has a li-fe 3.3V program that suits the saphions better. Their Volts are 3.1 per cell. If you have either of these programs on your Delta-peak it should be alright. Overlander are the peaple who sell them. Hope this helps
John

[Danny Fenton]

I have been using A123 cells, stripped from DeWalt battery packs for a little while and they are perfect for blasting my Wot4 about. I use 6S1P through an 800 watt motor and can recharge in the plane on the field in about 15 minutes @ 10A
http://media.putfile.com/First-flight-electric-conversion-Wot-4

[Scrooge Howard]

If we are talking of "Saphions" ,John Ogier states correctly , they are Lithium Phosphate cells.
Myself & four friends have been using them for around 2 years now and found them to be excellent , trouble free , tolerant of abuse ,equivalent in voltage ,( 9.6v/ 3 cell pack),to an 8 cell NiMh pack but lighter, and found to enhance the performance of all the models we have used them in . We now no longer purchase 8 cell Ni based packs for 1200Mah , applications and can`t think why they are not more popular.
After watching a fellow club member using another "Lithium Phosphate" based, (A123),pack , early days yet ,but so far we are equally impressed .
Nothing yet however quite seems to match the sheer power/weight ratio of the Li-Po`s ,so in spite of their draw backs we are tending to use them more & more

[Peter Burgess]

Will these cells be offered in a 2s pack as according to guys in the USA they make an excellent Rx pack? (Good voltage stability and no need for a regulator)

Pete

[Scrooge Howard]

More thoughts . We use very basic, but good, 3 cell £16 Perkins Lipo chargers .
The "Saphions" are almost idiot proof, certainly no more hazardous than their NiCad equivalents , they hold their charge well , we have flown them sucessfully several weeks after their last charge , without "Topping Up" , unlike Ni/types , & they also seem to have at least as good a shelf life . Unfortunately up till now , they have only been available in one cell size , but we have sucessfully "Paralled" 2 Standard 3 cell S packs , (to power an "Axi 28/20 /10" motor , using a 12 x 6 prop) .
Occasionally , when I`ve over discharged during a flight , I`ve been able to restore to normal use by carefully applying a small charge, ( about 250 Ma for about 5 mins), using an ordinary Ni/type charger , before connecting to the LiPo charger for completion , (something I would not even contemplate doing with a LiPoly or LiIon battery) . But "Hey" don`t copy me , use your loaf & don`t over discharge in the !st place .
I look forward to seeing more suppliers/manufactures providing greater choice in this "Not So Worrying" Phosphate technology.

[John Dobson 2]

Lithium ion and Saphion cells have been around for some time now ,why have they taken so long to get recognised for modelling purposes. They are more stable than the dreaded Lipos.Or is there some ulterior motive against them?. Regards John Dobson.

[Danny Fenton]

A possible reason John, and not wishing to come across as a cynic, but LiPos are probably good for business, after all they are fairly easy to damage, and therefore need replacing. Add to that they take a while to charge, therefore you need spare packs. M1's on the other hand, you only need one set of cells, and it charges in 15 mins. Lipos do have a better power to weight ratio, but in my oppinion that is all they have in their favour.

[John Ogier]

One of the things that restrict the saphions a bit is their discharge rate. They can only be used at 15C. I use 2400 19.5 6S2P packs which means I can only use 36 amps. I have used more (42-43amps) by mistake and they sort of collapse, but seem alright after the next charge. The 3300 18.5v 5S lipos can be used at higher amps with no problems and seem to hold their voltage better which gives a slightly better performance at the 37 amp max. of the motor.

[Danny Fenton]

Hi John, I am referring to lithium Ion, nano phoshates, A123 M1 cells, these can be (we have done it) discharged at up 110A, and recharged from flat in 15 mins. The Sapphions I am not familiar with.

[Danny Fenton]

Something that is often forgotten, A123's will give their power right up to the 2300mAH, then the voltage crashes, but up to that point the voltage is solid. How far can/dare you push a 2300mAH LiPo?.... 1700.....2000? They may be heavier than LiPo but if you have to double up your LiPo packs to get the capacity then the weight advantage soon vanishes. M1's will deliver as much power at the end of the flight as they do at the start.

Danny

[Helidel]

Hi everybody,

Have just charged my Orca Tx lipo for the first time since installing it in my Spekky

in June !! Clock says 11.6 hrs on-time.

Was bought at Wings & Wheels and was more costly than from UH but well worthit.

Trying to convert some of my "oily" flyer friends seems to be a waste of time, they often recharge after a couple of flights! so I've stopped telling them about the advantages.  

Timbo,

A long time ago I mentioned the Lipos I got from HK cheap-cheap, I've used them in my Katana30e and my Vanquish and they are still holding up as well as my dear-dear ones! But moving to 4S I'll go for FP.

Helidel