Lets talk Batteries
 

I am re configuring one of my jets to lose some dead nose weight. Right now I am running two A123 2300mAh batteries that I can remove from the jet for charging.

I have always set my jets up to be able to remove the batteries for charging with the exception of my F-86 that has a single 5 cell 2300mAh Nicad in the nose that is not accessible. I charge the Nicad on board.

My jet I am re doing will have a Powerbox Royal with the regulator set for the 6.0 volts. The lead in the nose of this jet will be removed and I can put the two A123's in the nose for balance. I am concerned with charging the A123's in the jet.

My other option is to install two 2300mAh 6 cell Nicad packs in the nose and i would be able to charge them in the jet.

What are your thoughts on this?
Anyone charging A123's on board your jet?
Any issues I.E. packs exploding.

Thanks Joe Lewis
Kingtech
K-80 and K-140 owner

I don't have 123s in my jets,Im a diehard fromeco li-ion guy, but I do have 123s in multiple other planes, and I have balance charged them in the plane from day 1, never any worries. I know the chemistry in them not supposed to be as volatile as Lipos, but I also believe lipos got their bad rep from people charging then wrong.

Charge them in the plane Joe. No more worries than charging NiCad's or Nickel metals.

Joe:

I have been using and charging A123 in my jets since early 2008. I use FMA 4s chargers (oldy but goodie).
Never an issue with A123s. I had 2 2S A123 and 2 3S A123 in my large A-10 and no issues charging without removing. Extremely safe.

Nick

I've been using A123s since they hit the market pretty much. I use them so I can charge them IN the airplane. Never had an issue and don't anticipate one. By far the most dummy proof batteries out there if you ask me.

I use A123's in my jets and never remove them from the plane for charginghttp://www.rcuniverse.com/forum/atta...mentid=2124364

All my jets have A123 2s packs and I charge all of them in the planes without removal. They are safe to be charged inside the fuse unlike LiPo batteries..

I absolutely hate to charge batteries in the plane. What a PITA to get at them with the planes in the trailer. And then, if you forget to charge them, you have to wait to charge them before flying versus just putting in some fresh ones. Also you are committed to the batteries in the plane. If you detect a weak battery = no flying, at least for an hour. And, ... then there is stopping in the middle of the day to charge them back up again, ... another hour. This also forces you to carry a generator or a 12 Volt battery, if you don't mind waiting for a longer charge off a battery. And then you have to remember to charge that battery before you go.

Also, if you do not have permanent batteries, you can use just a couple packs for multiple planes. This way you don't have to have dedicated packs for each plane. Saves $s and you don't have to worry about putting batteries in storage mode when the plane is not being used for a while, etc.

If there is any way to avoid installing batteries permanently in a plane I do it. You don't know what your missing until you set up the plane to allow easy battery removal for charging and just swapping in fresh ones.

I do have one plane that I am forced to have installed batteries. I have A123s because they are not supposed to catch fire. Also, Electro-Dynamics has a nice setup for balance charging these in the plane.

We have had one jet in our club burn down with LiPo charging in the Plane. That fire also got a second plane. Can not attest to how that battery was being charged. But I have never had a LiPo go up in smoke when charging. And I have charged LiPos that were bashed, puffed and had marginal cells. I even still have one I use that puffed and I bled off the gas in each cell and resealed it, ... two years ago. It still works and charges fine! Although, I would never charge that one in a plane.

I do like LiPos. I use all HV Digital Servos and some sort of powerbox or power expanders. In a plane that does not need the fast servo response or higher torque, I cut the voltage back. A HV servo will never burn out on 6 volts. I trust LiPos. But I do not charge them in a plane as I enjoy the advantages of them not being permanently installed.

You can charge the a123s in the plane but make sure your cell count on your charger is set right or have a smart charger like the cell pro 4. I blew the nose off my shockjet once when I charged one of me flight pack 2 cells on 3 cell charge rate. Charged about 5 minutes then pow the nose was gone. Picked up a cell pro 4 and been charging batteries in plane for a couple of years now.

+1

I have been using LiFe (a123s and others) for the last 5 years. I use them on everything. Fuel pump Air compressor,Blower, even my dustbuster. I tried to blow one up early on just to see what happened. The only thing that happened was the cap popped off the can. The other reason is that they hold a charge for a very long time (very low self discharge rate) and with a top off are ready to go quickly

Thank you for all the advice. It seems that charging them on board is not an issue so I believe they will get installed in the nose. I really don't like to carry dead weight, so the lead in the nose is going. The batteries will become my nose weight. Just so happens that the batteries weight the same as the lead in the nose.

Thanks
Joe Lewis
Kingtech
K-80 and K-140
Owner

HI, I been charging both the original A-123"s and now Electrodymanics A123"s since they first came out in my Bobcats and Bandits, never a problem, and you can"t kill these batteries, they just keep on working.
Rcpete

There are advantages and disadvantages to everything. But I hate dead weight so much that in some planes where there is little extra room and CG issues, I do the exact same thing you will do by using batts as ballast in sometimes inaccessible areas. I do have the ability to swap a pack out in 15 minutes though, if I chose, bc I built in a way to get at the packs but I'd hate to do it every time. It's so easy to charge in the jet if you set yourself up for success and that's easy. I have a long charge lead and balance lead that is zip tied together. I also zip tie the balance lead to the battery connector where it is easy to access in the jet to hook up for charging so there is no fussing for connectors. I hook up from the charger to the batteries and use a portable deep cycle battery as my field charger so it's no issue to charge at the plane, in the car, at the table, or anywhere else for that matter. Totally portable and not a pain at all. I've been charging Lipos since 2003 and Life and A123 are NOT Lipos. They are perfectly fine to charge in jets and do not represent a hazard during charge like Lipos do. The one thing I'd humbly recommend you do is to occasionally discharge and re charge the A123's or Life packs with a quality charger using a cycle function. It helps you know what the capacity of the packs are doing over time to make sure you don't have a battery problem. The charger will diagnose the pack when it cycles it if you have a good charger like a Revolectrix or what have you.

Another thing I forgot to mention is that the genuine A123 cell are recommended to be stored fully charged as opposed to the LiPo packs. The self discharge of these batteries is extremely low and so they will hold charge for weeks and even months.

I never charge in the jet . Life cell will puff also and can explode to... They keep the charge but not for month!!

A123 batteries are round cells and I have never seen one puff or explode. They hold the charge for a very long time. I have recharged after a few months and they hardly take any further charge if stored at full capacity as recommended. I always charge mine in the model and try to make sure I use no other batteries. I use them for fuel filler, air pump etc as well as 2 cell for Rx and 3 cell for ECU. I always charge at 4 amps so charging several planes does not take very long.

John

I am by no means an expert on RC and related electrical jelly bean stuff but having used LiFe batteries for at least the last three years almost exclusively I have not had a battery related issue whatsoever, indeed I just measured the capacity of two packs that have not been used for a considerable length of time (in excess of 18 months). Using a H9 battery load tester, battery one indicated 6.6v and under a 2 amp load dropped to 6.13v, battery two was similar but dropped to 6.15v; I understand that LiFe batteries exhibit different characteristics to conventional batteries but I believe this to be indicative of this chemistry and as a result I have the utmost confidence in my batteries, btw not all LiFe cells are created equal, these are from Booma RC.

Any A123 pack that loses more than 5% of it's capacity per year is junk, get rid of it. Also, genuine A123, as opposed to the foil encased LiFE packs are cylindrical steel case cells and will never puff, they are also vent before they explode. While there is no such thing as a 100% safe battery technology, genuine A123 packs come as close as anything out there today. I also use the FMA chargers and select 2.0C and they determine the capacity of the pack automatically during charge. I don't charge in the trailer as it's too inconvenient and simply charge at the filed while assembling the airplane. Rarely takes more than 15 minutes unless I had seriously drained the packs on the last outing.

Wayne

Sorry but you may want to read a bit more on true/genuine A123 cylindrical cells. They DO NOT PUFF. They cannot physically puff. they Will vent first in extreme abusive situation such as severe physical damage or excessive over-voltage charge. ALL my current jets (BVM Bandit MK II, Ultra Flash, BVM Bobcat, Comp Arf Spark) all have these genuine A123 cylindrical cells. Per spec they are recommended to be stored fully charged. In the past, after one year of storage I have barely put it 20-30mAh charge in a 2300mAh 2s packs,

Here is some info to start with.

http://hangtimes.com/a123_batteries_for_giants_faq.html

You right round cell do not puff they vent..I was mistaken with LIFE not A123

If you are going to an on board regulator from a PB or CB... and need to bury the batteries, to me its a No Brainer..LiONs..

put some Fromeco Lithium Ion 5200 packs in the nose.. they are almost the same weight as the A123 pack.. you can charge them at 1C in the jet.. Have done it for years.. Thats my preferred setup with a regulator. High capacity, good Impedence. easy peasy to charge..

Call them and tell them what config and how long of wire and what plug.. I usually get them in a 2x2 long stick with 12 inches and a Deans.

No balancing required.


IFyou are not using regulators, then A123's or recently I started using BUDDY RC Life Packs.. you must balance charge A123/Life every time however.. If you balance charge and check them every time, you will be fine.. I did a lot and I mean a lot of testing on A123's back in the day.. they are insidious about getting out of balance due to the flat discharge curve..

Bottom line go with something you understand and are comfortable with..

I have to disagree with you on this one as Lions are about the only battery technology I won't use anymore. They simply have the lowest C ratings of any of the battery technologies that we currently use and take forever to recharge compared to A123s. I'm sure they would be fine for a jet as they don't draw nearly as much as a typical giant scale aerobatics plane but since they charge so slowly and I need to run such BIG packs in order for LIONS to cover the demands of a giant scale aerobatics airplane I stopped using them a long time ago..

Yup Wayne, respectfully, it was just my opinion for what its worth..

Most of my planes have A123/Life packs.
Yes Life's charge faster and are much more convenient, but if I have to bury the packs with a regulator, it is the proven safest power system.
If I had to bury packs without a regulator, then the 2300 A123 is a preferred. But I still like to be able to touch them for warmth, or smell them if they vent.. I have had about 6 cells vent over the years. but since I started using higher quality balance chargers, Life's have been perfect.

You pointed out the downsides of course.. everything is a tradeoff as you know.

If using Life's or A123's for buried packs, then suggest to Jetpilot24 to ditch the regulator, it isn't needed. Lots of ways to skin the cat, Thats why I really Like the Jeti CB200. and the spectrum Powersafe receivers..

Yup, just opinions and everyone decides for themselves what is best. I was simply offering a different point of view and why I felt that way so others could judge the merit of that opinion for themselves. As long as equipment choices are based on an understanding of your needs and the pluses and minuses of your choices then that's a good decision. My real point was that for a different model, there may be very different requirements and therefore different equipment choices may be better. Even for the same model, someone with different needs / requirements may feel very differently about what's best for them.

I also always liked the power-safe receivers and now that I've switched to Jeti, I like the CB200 even better. Still, for some of my models that I don't feel need a power expander such as the CB200, I still prefer the simplicity of a single receiver. For example, my Boomerang XL, which I allow others to fly so they can try a turbine, has a single receiver since my DS16 can't use dual path while operating in Student/Teacher mode. If I didn't have the requirement of using student teacher mode, the boomerang may well have a CB200 installed. Still, review of the telemetry logs from MANY flights on the Boomerang have shown that the single receiver has always performed flawlessly and that it was a perfectly good choice for this model.