I see a lot of people doing this successfully. I don't think they are using the balance port though. One guy showed me how to bypass it by soldering a balance port to the main pos & neg leads then plugging that directly to the charger (bypassing the balance plug on the back of the battery). Hope I'm explaining this right, Any thoughts?

On my A123s I charge inside the plane (they are hard to get too). They are only 2 cell for receiver so I soldered regular servo wire leads to the balance ports then I ran them to the main hatch where I use them to balance charge. I never charge with out balancing. Its the best way to catch a cell going bad and keep from cooking something.

Any mistake on your part in setting the charger, connecting the plug(s), or a problem with the pack thats not diagnosed and your plane, workshop, or immediate area are at risk of fire.
Best advice if your not sure, but even then its not good practice, is to remove your battery pack, any chemistry, and charge the pack out of the plane/vehicle. Its the safest way to ensure you know the packs condition and your able to respond to a problem immediately.
Best of all get a steel box like an ammo box, electrical junction box, or similar and modify it to be your charging bunker. Pass the wires through the wall and use a rubber grommet, thats it, and you will have a secure charging set up. Just be sure to allow some sort of exhaust port to let the pressure and hot gases to exit the box. Otherwise it can be dangerous as well.

A123's I think are fine to charge in the plane through the balance port. I agree with always balancing. Make sure you trust yourself and your charger. It's easy to select the wrong chemestry or charge rates and that's when bad things happen.

I'm careful about it but I sometimes even charge Lipos in the plane .. that's when you need to be extra careful. Never more than 1C and monitor it like a hawk. I've never had a lipo catch fire at any charge rate but others have. The thing I have had with a lipo is a hole poked into the foil .... BAD NEWS. When charging the gas comes out of the hole and it's incredibly flamable. Dont use them .. with a hole in them the cell goes dead pretty soon anyway.

I have had NiMh batteries explode. Even when set to the right charge rate. They did not catch fire but the explosion was powerful to blow the pack apart.

I plan on doing a really pretty install utilizing the simulated carbon material, & need to figure an easily removable tray for battery access, but there will be a lot of connecting/disconnecting every flight. It may actually be safer to extend the balance port & charge my dual life packs inside. It seems to be what most people are doing

Something like this? I built this for my CARF Tucano.





Regards, Bart.

If you are using A123's as its only two cell you can use an ordinary Rx plug for both the charge and balance lead, just use the signal wire as the center tap, I use one of the external fus charge sockets to retain the plug inside the airframe and plug my balance lead into it, hope I have explained that OK.

Mike

I never charge in the plane...it's not worth burning down my plane
I velcro in all my packs in a spot I can reach them

Thanks guys... Bart, that looks really cool!

same me,<span style="font-family: Verdana, Arial; font-size: 13px; background-color: rgb(251, 252, 255);">use one of the external fus charge sockets to retain the plug inside the airframe and plug my balance lead into it, hope I have explained that OK.</span><font face="Verdana, Arial" size="2"></font>

I charge my A123's in the plane using a basic switch withcharge port. All you have to do is pull the signal wire that goes to the receiver, so that the receiver gets only the red and black leads. Otherwise you'll have 3.3 volts going into the receiver on the signal wire, whichcan damage the receiver.

Here's the link that explains how to make the mod.http://hangtimes.com/a123rxsetup.html. Read the "Basic Combo Solution Switch Mod..." section.

Very simple and convenient.

Joe

Maybe I need to read that again, but it appears they're saying you need a gen2 charger (no banana plugs) & a special NoBS (combo charge/balance lead, no molex port) liFe pack. My hobbico lifeSource has a molex balance lead on one end, & apparently my TP820 is a gen1 charger.

The battery pack needs to have a standard servo plug on the balance lead. A lot of A123 packs are sold that way.

You can usea Gen 1 charger if you have his adapter harness, oryou can make your own. If you have a Gen 2 chargerthenyou need an adapter with a balance plug on one end and a standard servo plug on the other.

Once you have the adapter harness it's very easy to convertyourplanes from nicads to A123's. There are no special switches or anything else to buy.

Joe

I own a few hundred Li-Po packs, all my jets use Li-Po's on ECU and Rx (2) (OK actually I have a Li-Fe in my Bobcat P-100Rx) I've been using Li-Po's since they were released in the early 2000's and other than showing people what can happen with charge abuse, I've never had an explosion or fire. I have blown up lots of duff/massive out of balance packs to learn what it takes.
You get lots of notice, so people that say they 'just exploded' are normally not telling you the whole story. Sound (the bags/heat shrink make lots of noise stretching) Smell...sweet odour is always present just before they go, temperature, warm cells are BAD!
I would not install Li-Po's where you couldn't quickly get them out-most of my packs have just HD Velcro and no strap. All easily accessible.
I have thousands of charge cycles and I'm very comfortable charging Li-Pos, but I use good clear chargers and always charge while i'm in the room. I monitor the cell voltages (easy on good chargers) I check when its first put on charge and 3-4 times during each charge. Cells that are more than 0.1V out of balance need careful consideration as they are probably never going to be right (if new) and need special attention if they were good balanced cells and have now got way out...Even one instance of huge abuse will reduce the life of a pack...

It comes down to you, your attention span and ability to be regimented on your routine.

Dw

Oh, I always connect the balancer..

From what I'm reading on LifePo packs, you probably couldn't get them to catch fire if you tried. It seems the highest possibility will be to puncture them. I can not find a single incident of a Life pack catching fire inside a model, So I am leaning toward carefully charging them inside on my aircraft, unless I can devise the setup I want & figure a way to remove the 3packs. Joe- that's some very good info, & Dave, this is for my UF.. If I place my 2-2100mah bats in the standard location with my P-100rx, I will have to add lead, & I HATE, HATE, HATE LEAD!!! so I'll probably shift the batts into the nose & figue a way to extend the balance leads, then charge carefully & watch them like a hawk. thought about making the nose removable with a batt tray, then I could remove & charge all 3 batts, but dont really want to add the weight of that either

that looks awesome! any pics of it installed? you remove the entire plate then charge outside the plane?

Depends on your Rx Li-Po sizes The battery pockets we devised on the Flash range is where my batteries sit. With a P-100 (lighter) you should get away without any weight. I build the model and select battery capacity to make up the weight!

Dave

Agreed 100%, best technique going! I'll do my fancy textured paint/carbon fiber deck I want, then see what batt position works. MAH=good ballast (Much better than lead).. But as far forward as possible = less MAH & weight necessary to get it done.