I have a 11.1V 1250mah 3S 15c Lipo Battery, heres a link to it. [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJRY3]Link[/link] And I have the [link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXHNW5]Great Planes PolyCharge Lithium Polymer DC Charger[/link]. It has a 3 selection switch for 250, 500, or 1000mA. Which setting do I use it for my battery. Also I tried clipping the charger to my 12V battery wall charger and it just beeped the whole time, so instead I just clipped the charger to the 12V battery and it doens beep but the light for charging comes on. Could someone give me some tips on charging these types of batteries and how to tell what setting to charge on with different batteries.

.1C is considered the maximum charge rate for LiPo packs. That's 1/10th battery capacity. 1250 mah battery pack (1.25 Amp Hours) means to charge it at a charge rate of about .125 amps. In this case, 250 is the lowest range on your charger.. to bad you don't have that goes one octave down.. 125 ma.. but if that's what you have, then that will have to do. Just be careful.

There are fast chargers that do it much faster, but be very careful using them.

ALWAYS charge your LiPo packs outside never in the house, or in your car/truck/van whatever. LiPo packs are dangerous.

CGr.

A guy from the field had his car burn to the ground when his battery pack exploded while charging between flights. So I guess there is no safe place to charge. I wonder if the AMA would cover something like that? Anyone know?

Set the charger on 1000mAh

Clip it to a 12v battery (I use my car battery)

Plug in the battery. BE SURE THE BATTERY IS IN A SAFE PLACE - Do a YouTube search for "Exploading LiPo" and you'll see why.

The light should come on. When the pack is fully charged (About an hour, maybe two) it should start beeping.

If the charger starts beeping right away, the pack may be too low to start with. If that happens let me know and we'll try something else.

LiPo safety has gotten a lot better, largely due to improved charging methods. I still keep my batteries in a "LiPo Sack" when charging them. It's just a reinforced bag with a Velcro enclosure. If something goes wrong, it'll vent the gas and contain the fire. It's just one way of doing it. People use ammo cans, large ceramic pots, you name it.

I just set it to 1000mA and its not beeping so it seems to be fine. Im still learning this stuff so why did CGretired say to set it to 250 and you say 1000, whats the difference?

Minn, it just started beeping, it was only charging for 5 mins then it started to beep. Do you know why?

Ok, sometimes, if a LiPo drops below a certain voltage, the charger won't charge it.

What I have done... And this is NOT a safe thing to do... is to hook it directly to the 12v battery. BUT, Only for about 3 - 5 minutes and stay right there holding it to make sure it doesn't get hot!

After a few minutes, disconnect it and try using the charger again.

PS, Also, before you try the above, make sure the 12v battery you are using is fully charged. I have an extra car battery in my garage that I would charge LiPos with, and had the same problem as you once - it turned out the 12v battery had run down.

You can charge the Lipo at 1C in most cases. That means a 1250mAh battery could be charged at 1250mA (1.25A). With your charger, 1000mA is as close as you can get.

If I am at home and time is not a factor, I charge at 1/2C. I just figure it is easier on the batteries but I don't know for certain that is actually the case. At the field, I charge at 1C since it is quicker. You can always charge at any rate less than 1C just be sure to never exceed 1C.

If you want a good lipo charger you can grow with, check out the Turnigy Acucell-6 from www.hobbycity.com It's only $39 and will charge/balance up to 6-cell packs and up to 5A. I was skeptical at first but it has turned out to be the best charger I own.

You should always balance your lipos. It will make them last much longer and perform better.

A lipo-sack is a good investment but an old ammo can or ceramic jar with a lid is better than nothing too.

I went to the site but which charger is it?

Since Beach has a 3c battery, doesn't it need to be balanced? I have a 2c battery, and everyone keeps saying "you CAN balance it" but I don't know what that means. It would be nice to hear about balancing for those of us also new at lipos.

If you have a 3-cell Lipo pack, and one cell is lower than the other two, and you charge all three in series (Like NiCad cells are charged) you run the risk of over-charging two of the cells - which could lead to a fire or explosion.

Most pack nowadays have two plugs. One is for running the airplane and it's in series. The other is a single ground, but it has a positive lead for each cell. When you use a balancer (or a balanced charger) the charger detects the amount of charge in each cell and charges them as they need it so that no one cell gets too much.

I think you might be getting the C-rating mixed up with the cell count. "C" stands for capacity. You'll see a lipo rated at say "20C". That means for example that a 1000mAh (1A) battery, it can provide 20A of current (20 x Capacity).

When it comes to charging, 1C is generally the max current you can put into the battery. For example, a 2200mAh battery should be charged at no more than 2200ma (2.2A). You can always charge at a lower rate of course.

When denoting cell count manufacturers sometimes use an "S". For example you will see 2s (2 cell), 3S (3cell) and so on.

Here is a link to the charge I mentioned earlier. The thing is an excellent value: http://www.hobbycity.com/hobbycity/s...lancer/Charger

They also have one that ships from their US warehouse. It is $10 more but you pay less shipping.

Like Minnflyer said, good batteries will have a balance plug that allows a good charger to charge each cell equally. This is safer, will give better battery performance and prolong the life. You can see the balancing plug in the picture below.

Yeah I meant 2S and 3S. Batteries are listed as 2S for "2 cells in series" and 3s for "3 cells in series". Just a little confusing since we reference them as 2 cell and 3 cell and stuff.

So it sounds like a lipo should be balanced every time, and I should be balancing my two cell?

> Also I tried clipping the charger to my 12V battery wall charger <

You cannot drive a nicad or lipo charger from a wall charger. You must use a good source of DC current such as a lead-acid storage battery of adequate capacity or a power supply that runs on house current.

That's not exactly correct. The LiPo that I just bought came with a charger which has two methods of powering it. 1. From a cigarette lighter in a car/truck/RV/whatever, and 2. from a wall-wart type charger. Granted, the wall wart charger was made for it, so it's appropriate, however, it IS slow.

beachbrada

I also have a Triton and an ICE charger. Both will do a full charge in about an hour, and yeah, after I checked, it can be safely charged at 1C. 1/10 C (.1 C) will do it, but it will take several hours. I don't fly electrics all that often, so I forgot that I DO charge using my ICE charger at 1C. Sorry, beachbrada, for the confusion or the incomplete information.

CGr.

If it has a balance plug, it would be a good idea. Is it just a receiver battery? If so you may get away with regular charging at the field but balance it when charging at home. It won't get nearly as depleted or take the same abuse as a lipo driving a motor to power the plane.

Well Im still having trouble getting this battery charged, I hooked it up to my 12v battery fully charged and had it set to 1000mA and it sits for an hour then it beeps like its done charging. I hook it up to the plane and its weak, the reciever light is very dim and the servos dont move. Then I hooked up my regular reciever battery to the reciever and it comes online just fine with tons of power. So Im not sure if there is something wrong with the battery or charger. Im going to take it to the field today and hopefully the guy with the triton charger shows up so we can try it that way. Also Ive already tried hooking it up to the battery directly to try and jump start it like Minnflyer said but that didnt help.

Beach are you balancing your cells when charging? I think I read somewhere that the first charge is pretty crucial. Based on the information I've gathered from above, you might be charging only a cell or two if you're not balancing; the charger could be reading that these cells are full, but the extra 'empty' cell could be causing a lack of juice.

If it charged for an hour and beeped but it's still weak, I would have someone who KNOWS LiPos to check it out. If it still soesn't work, send it back if it's still in warranty, or get rid of it if it's not

If you are going to be using electric power much, it will behoove you to buy yourself a voltmeter. It doesn't have to be an expensive one either, even the $3/5 Harbor Freight units will do the job. Now you can measure each cell of your battery. On LiPo's, a fully charged cell will be 4.2 volts. Try to never discharge one below 3 volts/cell as that will often ruin it. And yes, it is good practice to always balance your battery when charging as, as said above, if one cell falls much below the others, you will most probably overcharge one or more cells. This is the most dangerous aspect of LiPo's (overchargeing) as that is when you can build up enough gas pressure to rupture the outside casing and possibly erupt in flame.

Guys thanks for all the help, it turns out it was something I overlooked that was causing the problem. I took the battery to the field and a fellow flyer had his fancy charger with him. We hooked it up and the battery showed that it was a little over charged, which was probably from me trying to charge it so much. Well we discharged it and pulled out about 600 mA from it. Then we charged it back up to 12.6v. I brought it back home and hooked it up, still not enough juice for the receiver. So the only thing left was trying a different servo extension, and it finally worked. So it turns out my servo extension was bad. It would send some power to the reciever just enough to turn the light on but thats it. Now with the new extension it works fine. Thanks again